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5555a83c82
fix comments, 80-column tweak Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: yangge <yangge1116@126.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
7093 lines
197 KiB
C
7093 lines
197 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/mm/page_alloc.c
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*
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* Manages the free list, the system allocates free pages here.
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* Note that kmalloc() lives in slab.c
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*
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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* Swap reorganised 29.12.95, Stephen Tweedie
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* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
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* Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
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* Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
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* Zone balancing, Kanoj Sarcar, SGI, Jan 2000
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* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
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* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
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*/
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#include <linux/stddef.h>
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#include <linux/mm.h>
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#include <linux/highmem.h>
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#include <linux/interrupt.h>
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#include <linux/jiffies.h>
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#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <linux/kasan.h>
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#include <linux/kmsan.h>
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#include <linux/module.h>
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#include <linux/suspend.h>
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#include <linux/ratelimit.h>
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#include <linux/oom.h>
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#include <linux/topology.h>
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#include <linux/sysctl.h>
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#include <linux/cpu.h>
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#include <linux/cpuset.h>
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#include <linux/pagevec.h>
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#include <linux/memory_hotplug.h>
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#include <linux/nodemask.h>
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#include <linux/vmstat.h>
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#include <linux/fault-inject.h>
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#include <linux/compaction.h>
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#include <trace/events/kmem.h>
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#include <trace/events/oom.h>
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#include <linux/prefetch.h>
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#include <linux/mm_inline.h>
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#include <linux/mmu_notifier.h>
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#include <linux/migrate.h>
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#include <linux/sched/mm.h>
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#include <linux/page_owner.h>
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#include <linux/page_table_check.h>
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#include <linux/memcontrol.h>
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#include <linux/ftrace.h>
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#include <linux/lockdep.h>
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#include <linux/psi.h>
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#include <linux/khugepaged.h>
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#include <linux/delayacct.h>
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#include <linux/cacheinfo.h>
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#include <linux/pgalloc_tag.h>
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#include <asm/div64.h>
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#include "internal.h"
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#include "shuffle.h"
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#include "page_reporting.h"
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/* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
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typedef int __bitwise fpi_t;
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/* No special request */
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#define FPI_NONE ((__force fpi_t)0)
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/*
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* Skip free page reporting notification for the (possibly merged) page.
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* This does not hinder free page reporting from grabbing the page,
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* reporting it and marking it "reported" - it only skips notifying
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* the free page reporting infrastructure about a newly freed page. For
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* example, used when temporarily pulling a page from a freelist and
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* putting it back unmodified.
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*/
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#define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
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/*
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* Place the (possibly merged) page to the tail of the freelist. Will ignore
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* page shuffling (relevant code - e.g., memory onlining - is expected to
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* shuffle the whole zone).
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*
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* Note: No code should rely on this flag for correctness - it's purely
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* to allow for optimizations when handing back either fresh pages
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* (memory onlining) or untouched pages (page isolation, free page
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* reporting).
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*/
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#define FPI_TO_TAIL ((__force fpi_t)BIT(1))
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/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
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static DEFINE_MUTEX(pcp_batch_high_lock);
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#define MIN_PERCPU_PAGELIST_HIGH_FRACTION (8)
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#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
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/*
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* On SMP, spin_trylock is sufficient protection.
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* On PREEMPT_RT, spin_trylock is equivalent on both SMP and UP.
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*/
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#define pcp_trylock_prepare(flags) do { } while (0)
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#define pcp_trylock_finish(flag) do { } while (0)
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#else
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/* UP spin_trylock always succeeds so disable IRQs to prevent re-entrancy. */
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#define pcp_trylock_prepare(flags) local_irq_save(flags)
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#define pcp_trylock_finish(flags) local_irq_restore(flags)
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#endif
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/*
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* Locking a pcp requires a PCP lookup followed by a spinlock. To avoid
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* a migration causing the wrong PCP to be locked and remote memory being
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* potentially allocated, pin the task to the CPU for the lookup+lock.
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* preempt_disable is used on !RT because it is faster than migrate_disable.
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* migrate_disable is used on RT because otherwise RT spinlock usage is
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* interfered with and a high priority task cannot preempt the allocator.
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*/
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#ifndef CONFIG_PREEMPT_RT
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#define pcpu_task_pin() preempt_disable()
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#define pcpu_task_unpin() preempt_enable()
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#else
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#define pcpu_task_pin() migrate_disable()
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#define pcpu_task_unpin() migrate_enable()
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#endif
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/*
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* Generic helper to lookup and a per-cpu variable with an embedded spinlock.
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* Return value should be used with equivalent unlock helper.
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*/
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#define pcpu_spin_lock(type, member, ptr) \
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({ \
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type *_ret; \
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pcpu_task_pin(); \
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_ret = this_cpu_ptr(ptr); \
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spin_lock(&_ret->member); \
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_ret; \
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})
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#define pcpu_spin_trylock(type, member, ptr) \
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({ \
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type *_ret; \
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pcpu_task_pin(); \
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_ret = this_cpu_ptr(ptr); \
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if (!spin_trylock(&_ret->member)) { \
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pcpu_task_unpin(); \
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_ret = NULL; \
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} \
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_ret; \
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})
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#define pcpu_spin_unlock(member, ptr) \
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({ \
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spin_unlock(&ptr->member); \
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pcpu_task_unpin(); \
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})
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/* struct per_cpu_pages specific helpers. */
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#define pcp_spin_lock(ptr) \
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pcpu_spin_lock(struct per_cpu_pages, lock, ptr)
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#define pcp_spin_trylock(ptr) \
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pcpu_spin_trylock(struct per_cpu_pages, lock, ptr)
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#define pcp_spin_unlock(ptr) \
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pcpu_spin_unlock(lock, ptr)
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#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
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DEFINE_PER_CPU(int, numa_node);
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EXPORT_PER_CPU_SYMBOL(numa_node);
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#endif
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DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
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#ifdef CONFIG_HAVE_MEMORYLESS_NODES
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/*
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* N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
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* It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
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* Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
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* defined in <linux/topology.h>.
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*/
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DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
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EXPORT_PER_CPU_SYMBOL(_numa_mem_);
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#endif
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static DEFINE_MUTEX(pcpu_drain_mutex);
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#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
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volatile unsigned long latent_entropy __latent_entropy;
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EXPORT_SYMBOL(latent_entropy);
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#endif
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/*
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* Array of node states.
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*/
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nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
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[N_POSSIBLE] = NODE_MASK_ALL,
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[N_ONLINE] = { { [0] = 1UL } },
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#ifndef CONFIG_NUMA
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[N_NORMAL_MEMORY] = { { [0] = 1UL } },
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#ifdef CONFIG_HIGHMEM
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[N_HIGH_MEMORY] = { { [0] = 1UL } },
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#endif
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[N_MEMORY] = { { [0] = 1UL } },
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[N_CPU] = { { [0] = 1UL } },
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#endif /* NUMA */
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};
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EXPORT_SYMBOL(node_states);
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gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
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unsigned int pageblock_order __read_mostly;
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#endif
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static void __free_pages_ok(struct page *page, unsigned int order,
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fpi_t fpi_flags);
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/*
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* results with 256, 32 in the lowmem_reserve sysctl:
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* 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
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* 1G machine -> (16M dma, 784M normal, 224M high)
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* NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
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* HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
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* HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
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*
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* TBD: should special case ZONE_DMA32 machines here - in those we normally
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* don't need any ZONE_NORMAL reservation
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*/
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static int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
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#ifdef CONFIG_ZONE_DMA
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[ZONE_DMA] = 256,
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#endif
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#ifdef CONFIG_ZONE_DMA32
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[ZONE_DMA32] = 256,
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#endif
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[ZONE_NORMAL] = 32,
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#ifdef CONFIG_HIGHMEM
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[ZONE_HIGHMEM] = 0,
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#endif
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[ZONE_MOVABLE] = 0,
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};
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char * const zone_names[MAX_NR_ZONES] = {
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#ifdef CONFIG_ZONE_DMA
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"DMA",
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#endif
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#ifdef CONFIG_ZONE_DMA32
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"DMA32",
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#endif
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"Normal",
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#ifdef CONFIG_HIGHMEM
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"HighMem",
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#endif
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"Movable",
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#ifdef CONFIG_ZONE_DEVICE
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"Device",
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#endif
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};
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const char * const migratetype_names[MIGRATE_TYPES] = {
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"Unmovable",
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"Movable",
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"Reclaimable",
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"HighAtomic",
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#ifdef CONFIG_CMA
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"CMA",
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#endif
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#ifdef CONFIG_MEMORY_ISOLATION
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"Isolate",
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#endif
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};
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int min_free_kbytes = 1024;
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int user_min_free_kbytes = -1;
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static int watermark_boost_factor __read_mostly = 15000;
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static int watermark_scale_factor = 10;
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/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
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int movable_zone;
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EXPORT_SYMBOL(movable_zone);
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#if MAX_NUMNODES > 1
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unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
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unsigned int nr_online_nodes __read_mostly = 1;
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EXPORT_SYMBOL(nr_node_ids);
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EXPORT_SYMBOL(nr_online_nodes);
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#endif
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static bool page_contains_unaccepted(struct page *page, unsigned int order);
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static bool cond_accept_memory(struct zone *zone, unsigned int order);
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static bool __free_unaccepted(struct page *page);
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int page_group_by_mobility_disabled __read_mostly;
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#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
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/*
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* During boot we initialize deferred pages on-demand, as needed, but once
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* page_alloc_init_late() has finished, the deferred pages are all initialized,
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* and we can permanently disable that path.
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*/
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DEFINE_STATIC_KEY_TRUE(deferred_pages);
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static inline bool deferred_pages_enabled(void)
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{
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return static_branch_unlikely(&deferred_pages);
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}
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/*
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* deferred_grow_zone() is __init, but it is called from
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* get_page_from_freelist() during early boot until deferred_pages permanently
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* disables this call. This is why we have refdata wrapper to avoid warning,
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* and to ensure that the function body gets unloaded.
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*/
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static bool __ref
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_deferred_grow_zone(struct zone *zone, unsigned int order)
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{
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return deferred_grow_zone(zone, order);
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}
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#else
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static inline bool deferred_pages_enabled(void)
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{
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return false;
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}
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static inline bool _deferred_grow_zone(struct zone *zone, unsigned int order)
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{
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return false;
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}
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#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
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/* Return a pointer to the bitmap storing bits affecting a block of pages */
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static inline unsigned long *get_pageblock_bitmap(const struct page *page,
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unsigned long pfn)
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{
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#ifdef CONFIG_SPARSEMEM
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return section_to_usemap(__pfn_to_section(pfn));
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#else
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return page_zone(page)->pageblock_flags;
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#endif /* CONFIG_SPARSEMEM */
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}
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static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn)
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{
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#ifdef CONFIG_SPARSEMEM
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pfn &= (PAGES_PER_SECTION-1);
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#else
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pfn = pfn - pageblock_start_pfn(page_zone(page)->zone_start_pfn);
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#endif /* CONFIG_SPARSEMEM */
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return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
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}
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/**
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* get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
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* @page: The page within the block of interest
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* @pfn: The target page frame number
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* @mask: mask of bits that the caller is interested in
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*
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* Return: pageblock_bits flags
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*/
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unsigned long get_pfnblock_flags_mask(const struct page *page,
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unsigned long pfn, unsigned long mask)
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{
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unsigned long *bitmap;
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unsigned long bitidx, word_bitidx;
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unsigned long word;
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bitmap = get_pageblock_bitmap(page, pfn);
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bitidx = pfn_to_bitidx(page, pfn);
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word_bitidx = bitidx / BITS_PER_LONG;
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bitidx &= (BITS_PER_LONG-1);
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/*
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* This races, without locks, with set_pfnblock_flags_mask(). Ensure
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* a consistent read of the memory array, so that results, even though
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* racy, are not corrupted.
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*/
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word = READ_ONCE(bitmap[word_bitidx]);
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return (word >> bitidx) & mask;
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}
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static __always_inline int get_pfnblock_migratetype(const struct page *page,
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unsigned long pfn)
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{
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return get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK);
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}
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/**
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* set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
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* @page: The page within the block of interest
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* @flags: The flags to set
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* @pfn: The target page frame number
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* @mask: mask of bits that the caller is interested in
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*/
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void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
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unsigned long pfn,
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unsigned long mask)
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{
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unsigned long *bitmap;
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unsigned long bitidx, word_bitidx;
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unsigned long word;
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BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
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BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
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bitmap = get_pageblock_bitmap(page, pfn);
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bitidx = pfn_to_bitidx(page, pfn);
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word_bitidx = bitidx / BITS_PER_LONG;
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bitidx &= (BITS_PER_LONG-1);
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VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
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mask <<= bitidx;
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flags <<= bitidx;
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word = READ_ONCE(bitmap[word_bitidx]);
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do {
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} while (!try_cmpxchg(&bitmap[word_bitidx], &word, (word & ~mask) | flags));
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}
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void set_pageblock_migratetype(struct page *page, int migratetype)
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{
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if (unlikely(page_group_by_mobility_disabled &&
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migratetype < MIGRATE_PCPTYPES))
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migratetype = MIGRATE_UNMOVABLE;
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set_pfnblock_flags_mask(page, (unsigned long)migratetype,
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page_to_pfn(page), MIGRATETYPE_MASK);
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}
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#ifdef CONFIG_DEBUG_VM
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static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
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{
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int ret;
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unsigned seq;
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unsigned long pfn = page_to_pfn(page);
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unsigned long sp, start_pfn;
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do {
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seq = zone_span_seqbegin(zone);
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start_pfn = zone->zone_start_pfn;
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sp = zone->spanned_pages;
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ret = !zone_spans_pfn(zone, pfn);
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} while (zone_span_seqretry(zone, seq));
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if (ret)
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pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
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pfn, zone_to_nid(zone), zone->name,
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start_pfn, start_pfn + sp);
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return ret;
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}
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/*
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* Temporary debugging check for pages not lying within a given zone.
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*/
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static bool __maybe_unused bad_range(struct zone *zone, struct page *page)
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{
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if (page_outside_zone_boundaries(zone, page))
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return true;
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if (zone != page_zone(page))
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return true;
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return false;
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}
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#else
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static inline bool __maybe_unused bad_range(struct zone *zone, struct page *page)
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{
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return false;
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}
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#endif
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static void bad_page(struct page *page, const char *reason)
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{
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static unsigned long resume;
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static unsigned long nr_shown;
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static unsigned long nr_unshown;
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/*
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* Allow a burst of 60 reports, then keep quiet for that minute;
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* or allow a steady drip of one report per second.
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|
*/
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if (nr_shown == 60) {
|
|
if (time_before(jiffies, resume)) {
|
|
nr_unshown++;
|
|
goto out;
|
|
}
|
|
if (nr_unshown) {
|
|
pr_alert(
|
|
"BUG: Bad page state: %lu messages suppressed\n",
|
|
nr_unshown);
|
|
nr_unshown = 0;
|
|
}
|
|
nr_shown = 0;
|
|
}
|
|
if (nr_shown++ == 0)
|
|
resume = jiffies + 60 * HZ;
|
|
|
|
pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
|
|
current->comm, page_to_pfn(page));
|
|
dump_page(page, reason);
|
|
|
|
print_modules();
|
|
dump_stack();
|
|
out:
|
|
/* Leave bad fields for debug, except PageBuddy could make trouble */
|
|
if (PageBuddy(page))
|
|
__ClearPageBuddy(page);
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
}
|
|
|
|
static inline unsigned int order_to_pindex(int migratetype, int order)
|
|
{
|
|
bool __maybe_unused movable;
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
if (order > PAGE_ALLOC_COSTLY_ORDER) {
|
|
VM_BUG_ON(order != HPAGE_PMD_ORDER);
|
|
|
|
movable = migratetype == MIGRATE_MOVABLE;
|
|
|
|
return NR_LOWORDER_PCP_LISTS + movable;
|
|
}
|
|
#else
|
|
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
|
|
#endif
|
|
|
|
return (MIGRATE_PCPTYPES * order) + migratetype;
|
|
}
|
|
|
|
static inline int pindex_to_order(unsigned int pindex)
|
|
{
|
|
int order = pindex / MIGRATE_PCPTYPES;
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
if (pindex >= NR_LOWORDER_PCP_LISTS)
|
|
order = HPAGE_PMD_ORDER;
|
|
#else
|
|
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
|
|
#endif
|
|
|
|
return order;
|
|
}
|
|
|
|
static inline bool pcp_allowed_order(unsigned int order)
|
|
{
|
|
if (order <= PAGE_ALLOC_COSTLY_ORDER)
|
|
return true;
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
if (order == HPAGE_PMD_ORDER)
|
|
return true;
|
|
#endif
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Higher-order pages are called "compound pages". They are structured thusly:
|
|
*
|
|
* The first PAGE_SIZE page is called the "head page" and have PG_head set.
|
|
*
|
|
* The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
|
|
* in bit 0 of page->compound_head. The rest of bits is pointer to head page.
|
|
*
|
|
* The first tail page's ->compound_order holds the order of allocation.
|
|
* This usage means that zero-order pages may not be compound.
|
|
*/
|
|
|
|
void prep_compound_page(struct page *page, unsigned int order)
|
|
{
|
|
int i;
|
|
int nr_pages = 1 << order;
|
|
|
|
__SetPageHead(page);
|
|
for (i = 1; i < nr_pages; i++)
|
|
prep_compound_tail(page, i);
|
|
|
|
prep_compound_head(page, order);
|
|
}
|
|
|
|
static inline void set_buddy_order(struct page *page, unsigned int order)
|
|
{
|
|
set_page_private(page, order);
|
|
__SetPageBuddy(page);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPACTION
|
|
static inline struct capture_control *task_capc(struct zone *zone)
|
|
{
|
|
struct capture_control *capc = current->capture_control;
|
|
|
|
return unlikely(capc) &&
|
|
!(current->flags & PF_KTHREAD) &&
|
|
!capc->page &&
|
|
capc->cc->zone == zone ? capc : NULL;
|
|
}
|
|
|
|
static inline bool
|
|
compaction_capture(struct capture_control *capc, struct page *page,
|
|
int order, int migratetype)
|
|
{
|
|
if (!capc || order != capc->cc->order)
|
|
return false;
|
|
|
|
/* Do not accidentally pollute CMA or isolated regions*/
|
|
if (is_migrate_cma(migratetype) ||
|
|
is_migrate_isolate(migratetype))
|
|
return false;
|
|
|
|
/*
|
|
* Do not let lower order allocations pollute a movable pageblock
|
|
* unless compaction is also requesting movable pages.
|
|
* This might let an unmovable request use a reclaimable pageblock
|
|
* and vice-versa but no more than normal fallback logic which can
|
|
* have trouble finding a high-order free page.
|
|
*/
|
|
if (order < pageblock_order && migratetype == MIGRATE_MOVABLE &&
|
|
capc->cc->migratetype != MIGRATE_MOVABLE)
|
|
return false;
|
|
|
|
capc->page = page;
|
|
return true;
|
|
}
|
|
|
|
#else
|
|
static inline struct capture_control *task_capc(struct zone *zone)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline bool
|
|
compaction_capture(struct capture_control *capc, struct page *page,
|
|
int order, int migratetype)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_COMPACTION */
|
|
|
|
static inline void account_freepages(struct zone *zone, int nr_pages,
|
|
int migratetype)
|
|
{
|
|
lockdep_assert_held(&zone->lock);
|
|
|
|
if (is_migrate_isolate(migratetype))
|
|
return;
|
|
|
|
__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
|
|
|
|
if (is_migrate_cma(migratetype))
|
|
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
|
|
else if (is_migrate_highatomic(migratetype))
|
|
WRITE_ONCE(zone->nr_free_highatomic,
|
|
zone->nr_free_highatomic + nr_pages);
|
|
}
|
|
|
|
/* Used for pages not on another list */
|
|
static inline void __add_to_free_list(struct page *page, struct zone *zone,
|
|
unsigned int order, int migratetype,
|
|
bool tail)
|
|
{
|
|
struct free_area *area = &zone->free_area[order];
|
|
|
|
VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
|
|
"page type is %lu, passed migratetype is %d (nr=%d)\n",
|
|
get_pageblock_migratetype(page), migratetype, 1 << order);
|
|
|
|
if (tail)
|
|
list_add_tail(&page->buddy_list, &area->free_list[migratetype]);
|
|
else
|
|
list_add(&page->buddy_list, &area->free_list[migratetype]);
|
|
area->nr_free++;
|
|
}
|
|
|
|
/*
|
|
* Used for pages which are on another list. Move the pages to the tail
|
|
* of the list - so the moved pages won't immediately be considered for
|
|
* allocation again (e.g., optimization for memory onlining).
|
|
*/
|
|
static inline void move_to_free_list(struct page *page, struct zone *zone,
|
|
unsigned int order, int old_mt, int new_mt)
|
|
{
|
|
struct free_area *area = &zone->free_area[order];
|
|
|
|
/* Free page moving can fail, so it happens before the type update */
|
|
VM_WARN_ONCE(get_pageblock_migratetype(page) != old_mt,
|
|
"page type is %lu, passed migratetype is %d (nr=%d)\n",
|
|
get_pageblock_migratetype(page), old_mt, 1 << order);
|
|
|
|
list_move_tail(&page->buddy_list, &area->free_list[new_mt]);
|
|
|
|
account_freepages(zone, -(1 << order), old_mt);
|
|
account_freepages(zone, 1 << order, new_mt);
|
|
}
|
|
|
|
static inline void __del_page_from_free_list(struct page *page, struct zone *zone,
|
|
unsigned int order, int migratetype)
|
|
{
|
|
VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
|
|
"page type is %lu, passed migratetype is %d (nr=%d)\n",
|
|
get_pageblock_migratetype(page), migratetype, 1 << order);
|
|
|
|
/* clear reported state and update reported page count */
|
|
if (page_reported(page))
|
|
__ClearPageReported(page);
|
|
|
|
list_del(&page->buddy_list);
|
|
__ClearPageBuddy(page);
|
|
set_page_private(page, 0);
|
|
zone->free_area[order].nr_free--;
|
|
}
|
|
|
|
static inline void del_page_from_free_list(struct page *page, struct zone *zone,
|
|
unsigned int order, int migratetype)
|
|
{
|
|
__del_page_from_free_list(page, zone, order, migratetype);
|
|
account_freepages(zone, -(1 << order), migratetype);
|
|
}
|
|
|
|
static inline struct page *get_page_from_free_area(struct free_area *area,
|
|
int migratetype)
|
|
{
|
|
return list_first_entry_or_null(&area->free_list[migratetype],
|
|
struct page, buddy_list);
|
|
}
|
|
|
|
/*
|
|
* If this is less than the 2nd largest possible page, check if the buddy
|
|
* of the next-higher order is free. If it is, it's possible
|
|
* that pages are being freed that will coalesce soon. In case,
|
|
* that is happening, add the free page to the tail of the list
|
|
* so it's less likely to be used soon and more likely to be merged
|
|
* as a 2-level higher order page
|
|
*/
|
|
static inline bool
|
|
buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
|
|
struct page *page, unsigned int order)
|
|
{
|
|
unsigned long higher_page_pfn;
|
|
struct page *higher_page;
|
|
|
|
if (order >= MAX_PAGE_ORDER - 1)
|
|
return false;
|
|
|
|
higher_page_pfn = buddy_pfn & pfn;
|
|
higher_page = page + (higher_page_pfn - pfn);
|
|
|
|
return find_buddy_page_pfn(higher_page, higher_page_pfn, order + 1,
|
|
NULL) != NULL;
|
|
}
|
|
|
|
/*
|
|
* Freeing function for a buddy system allocator.
|
|
*
|
|
* The concept of a buddy system is to maintain direct-mapped table
|
|
* (containing bit values) for memory blocks of various "orders".
|
|
* The bottom level table contains the map for the smallest allocatable
|
|
* units of memory (here, pages), and each level above it describes
|
|
* pairs of units from the levels below, hence, "buddies".
|
|
* At a high level, all that happens here is marking the table entry
|
|
* at the bottom level available, and propagating the changes upward
|
|
* as necessary, plus some accounting needed to play nicely with other
|
|
* parts of the VM system.
|
|
* At each level, we keep a list of pages, which are heads of continuous
|
|
* free pages of length of (1 << order) and marked with PageBuddy.
|
|
* Page's order is recorded in page_private(page) field.
|
|
* So when we are allocating or freeing one, we can derive the state of the
|
|
* other. That is, if we allocate a small block, and both were
|
|
* free, the remainder of the region must be split into blocks.
|
|
* If a block is freed, and its buddy is also free, then this
|
|
* triggers coalescing into a block of larger size.
|
|
*
|
|
* -- nyc
|
|
*/
|
|
|
|
static inline void __free_one_page(struct page *page,
|
|
unsigned long pfn,
|
|
struct zone *zone, unsigned int order,
|
|
int migratetype, fpi_t fpi_flags)
|
|
{
|
|
struct capture_control *capc = task_capc(zone);
|
|
unsigned long buddy_pfn = 0;
|
|
unsigned long combined_pfn;
|
|
struct page *buddy;
|
|
bool to_tail;
|
|
|
|
VM_BUG_ON(!zone_is_initialized(zone));
|
|
VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
|
|
|
|
VM_BUG_ON(migratetype == -1);
|
|
VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
|
|
VM_BUG_ON_PAGE(bad_range(zone, page), page);
|
|
|
|
account_freepages(zone, 1 << order, migratetype);
|
|
|
|
while (order < MAX_PAGE_ORDER) {
|
|
int buddy_mt = migratetype;
|
|
|
|
if (compaction_capture(capc, page, order, migratetype)) {
|
|
account_freepages(zone, -(1 << order), migratetype);
|
|
return;
|
|
}
|
|
|
|
buddy = find_buddy_page_pfn(page, pfn, order, &buddy_pfn);
|
|
if (!buddy)
|
|
goto done_merging;
|
|
|
|
if (unlikely(order >= pageblock_order)) {
|
|
/*
|
|
* We want to prevent merge between freepages on pageblock
|
|
* without fallbacks and normal pageblock. Without this,
|
|
* pageblock isolation could cause incorrect freepage or CMA
|
|
* accounting or HIGHATOMIC accounting.
|
|
*/
|
|
buddy_mt = get_pfnblock_migratetype(buddy, buddy_pfn);
|
|
|
|
if (migratetype != buddy_mt &&
|
|
(!migratetype_is_mergeable(migratetype) ||
|
|
!migratetype_is_mergeable(buddy_mt)))
|
|
goto done_merging;
|
|
}
|
|
|
|
/*
|
|
* Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
|
|
* merge with it and move up one order.
|
|
*/
|
|
if (page_is_guard(buddy))
|
|
clear_page_guard(zone, buddy, order);
|
|
else
|
|
__del_page_from_free_list(buddy, zone, order, buddy_mt);
|
|
|
|
if (unlikely(buddy_mt != migratetype)) {
|
|
/*
|
|
* Match buddy type. This ensures that an
|
|
* expand() down the line puts the sub-blocks
|
|
* on the right freelists.
|
|
*/
|
|
set_pageblock_migratetype(buddy, migratetype);
|
|
}
|
|
|
|
combined_pfn = buddy_pfn & pfn;
|
|
page = page + (combined_pfn - pfn);
|
|
pfn = combined_pfn;
|
|
order++;
|
|
}
|
|
|
|
done_merging:
|
|
set_buddy_order(page, order);
|
|
|
|
if (fpi_flags & FPI_TO_TAIL)
|
|
to_tail = true;
|
|
else if (is_shuffle_order(order))
|
|
to_tail = shuffle_pick_tail();
|
|
else
|
|
to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
|
|
|
|
__add_to_free_list(page, zone, order, migratetype, to_tail);
|
|
|
|
/* Notify page reporting subsystem of freed page */
|
|
if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY))
|
|
page_reporting_notify_free(order);
|
|
}
|
|
|
|
/*
|
|
* A bad page could be due to a number of fields. Instead of multiple branches,
|
|
* try and check multiple fields with one check. The caller must do a detailed
|
|
* check if necessary.
|
|
*/
|
|
static inline bool page_expected_state(struct page *page,
|
|
unsigned long check_flags)
|
|
{
|
|
if (unlikely(atomic_read(&page->_mapcount) != -1))
|
|
return false;
|
|
|
|
if (unlikely((unsigned long)page->mapping |
|
|
page_ref_count(page) |
|
|
#ifdef CONFIG_MEMCG
|
|
page->memcg_data |
|
|
#endif
|
|
#ifdef CONFIG_PAGE_POOL
|
|
((page->pp_magic & ~0x3UL) == PP_SIGNATURE) |
|
|
#endif
|
|
(page->flags & check_flags)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static const char *page_bad_reason(struct page *page, unsigned long flags)
|
|
{
|
|
const char *bad_reason = NULL;
|
|
|
|
if (unlikely(atomic_read(&page->_mapcount) != -1))
|
|
bad_reason = "nonzero mapcount";
|
|
if (unlikely(page->mapping != NULL))
|
|
bad_reason = "non-NULL mapping";
|
|
if (unlikely(page_ref_count(page) != 0))
|
|
bad_reason = "nonzero _refcount";
|
|
if (unlikely(page->flags & flags)) {
|
|
if (flags == PAGE_FLAGS_CHECK_AT_PREP)
|
|
bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
|
|
else
|
|
bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
|
|
}
|
|
#ifdef CONFIG_MEMCG
|
|
if (unlikely(page->memcg_data))
|
|
bad_reason = "page still charged to cgroup";
|
|
#endif
|
|
#ifdef CONFIG_PAGE_POOL
|
|
if (unlikely((page->pp_magic & ~0x3UL) == PP_SIGNATURE))
|
|
bad_reason = "page_pool leak";
|
|
#endif
|
|
return bad_reason;
|
|
}
|
|
|
|
static void free_page_is_bad_report(struct page *page)
|
|
{
|
|
bad_page(page,
|
|
page_bad_reason(page, PAGE_FLAGS_CHECK_AT_FREE));
|
|
}
|
|
|
|
static inline bool free_page_is_bad(struct page *page)
|
|
{
|
|
if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
|
|
return false;
|
|
|
|
/* Something has gone sideways, find it */
|
|
free_page_is_bad_report(page);
|
|
return true;
|
|
}
|
|
|
|
static inline bool is_check_pages_enabled(void)
|
|
{
|
|
return static_branch_unlikely(&check_pages_enabled);
|
|
}
|
|
|
|
static int free_tail_page_prepare(struct page *head_page, struct page *page)
|
|
{
|
|
struct folio *folio = (struct folio *)head_page;
|
|
int ret = 1;
|
|
|
|
/*
|
|
* We rely page->lru.next never has bit 0 set, unless the page
|
|
* is PageTail(). Let's make sure that's true even for poisoned ->lru.
|
|
*/
|
|
BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
|
|
|
|
if (!is_check_pages_enabled()) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
switch (page - head_page) {
|
|
case 1:
|
|
/* the first tail page: these may be in place of ->mapping */
|
|
if (unlikely(folio_entire_mapcount(folio))) {
|
|
bad_page(page, "nonzero entire_mapcount");
|
|
goto out;
|
|
}
|
|
if (unlikely(folio_large_mapcount(folio))) {
|
|
bad_page(page, "nonzero large_mapcount");
|
|
goto out;
|
|
}
|
|
if (unlikely(atomic_read(&folio->_nr_pages_mapped))) {
|
|
bad_page(page, "nonzero nr_pages_mapped");
|
|
goto out;
|
|
}
|
|
if (unlikely(atomic_read(&folio->_pincount))) {
|
|
bad_page(page, "nonzero pincount");
|
|
goto out;
|
|
}
|
|
break;
|
|
case 2:
|
|
/* the second tail page: deferred_list overlaps ->mapping */
|
|
if (unlikely(!list_empty(&folio->_deferred_list))) {
|
|
bad_page(page, "on deferred list");
|
|
goto out;
|
|
}
|
|
break;
|
|
default:
|
|
if (page->mapping != TAIL_MAPPING) {
|
|
bad_page(page, "corrupted mapping in tail page");
|
|
goto out;
|
|
}
|
|
break;
|
|
}
|
|
if (unlikely(!PageTail(page))) {
|
|
bad_page(page, "PageTail not set");
|
|
goto out;
|
|
}
|
|
if (unlikely(compound_head(page) != head_page)) {
|
|
bad_page(page, "compound_head not consistent");
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
page->mapping = NULL;
|
|
clear_compound_head(page);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Skip KASAN memory poisoning when either:
|
|
*
|
|
* 1. For generic KASAN: deferred memory initialization has not yet completed.
|
|
* Tag-based KASAN modes skip pages freed via deferred memory initialization
|
|
* using page tags instead (see below).
|
|
* 2. For tag-based KASAN modes: the page has a match-all KASAN tag, indicating
|
|
* that error detection is disabled for accesses via the page address.
|
|
*
|
|
* Pages will have match-all tags in the following circumstances:
|
|
*
|
|
* 1. Pages are being initialized for the first time, including during deferred
|
|
* memory init; see the call to page_kasan_tag_reset in __init_single_page.
|
|
* 2. The allocation was not unpoisoned due to __GFP_SKIP_KASAN, with the
|
|
* exception of pages unpoisoned by kasan_unpoison_vmalloc.
|
|
* 3. The allocation was excluded from being checked due to sampling,
|
|
* see the call to kasan_unpoison_pages.
|
|
*
|
|
* Poisoning pages during deferred memory init will greatly lengthen the
|
|
* process and cause problem in large memory systems as the deferred pages
|
|
* initialization is done with interrupt disabled.
|
|
*
|
|
* Assuming that there will be no reference to those newly initialized
|
|
* pages before they are ever allocated, this should have no effect on
|
|
* KASAN memory tracking as the poison will be properly inserted at page
|
|
* allocation time. The only corner case is when pages are allocated by
|
|
* on-demand allocation and then freed again before the deferred pages
|
|
* initialization is done, but this is not likely to happen.
|
|
*/
|
|
static inline bool should_skip_kasan_poison(struct page *page)
|
|
{
|
|
if (IS_ENABLED(CONFIG_KASAN_GENERIC))
|
|
return deferred_pages_enabled();
|
|
|
|
return page_kasan_tag(page) == KASAN_TAG_KERNEL;
|
|
}
|
|
|
|
static void kernel_init_pages(struct page *page, int numpages)
|
|
{
|
|
int i;
|
|
|
|
/* s390's use of memset() could override KASAN redzones. */
|
|
kasan_disable_current();
|
|
for (i = 0; i < numpages; i++)
|
|
clear_highpage_kasan_tagged(page + i);
|
|
kasan_enable_current();
|
|
}
|
|
|
|
__always_inline bool free_pages_prepare(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
int bad = 0;
|
|
bool skip_kasan_poison = should_skip_kasan_poison(page);
|
|
bool init = want_init_on_free();
|
|
bool compound = PageCompound(page);
|
|
struct folio *folio = page_folio(page);
|
|
|
|
VM_BUG_ON_PAGE(PageTail(page), page);
|
|
|
|
trace_mm_page_free(page, order);
|
|
kmsan_free_page(page, order);
|
|
|
|
if (memcg_kmem_online() && PageMemcgKmem(page))
|
|
__memcg_kmem_uncharge_page(page, order);
|
|
|
|
/*
|
|
* In rare cases, when truncation or holepunching raced with
|
|
* munlock after VM_LOCKED was cleared, Mlocked may still be
|
|
* found set here. This does not indicate a problem, unless
|
|
* "unevictable_pgs_cleared" appears worryingly large.
|
|
*/
|
|
if (unlikely(folio_test_mlocked(folio))) {
|
|
long nr_pages = folio_nr_pages(folio);
|
|
|
|
__folio_clear_mlocked(folio);
|
|
zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
|
|
count_vm_events(UNEVICTABLE_PGCLEARED, nr_pages);
|
|
}
|
|
|
|
if (unlikely(PageHWPoison(page)) && !order) {
|
|
/* Do not let hwpoison pages hit pcplists/buddy */
|
|
reset_page_owner(page, order);
|
|
page_table_check_free(page, order);
|
|
pgalloc_tag_sub(page, 1 << order);
|
|
|
|
/*
|
|
* The page is isolated and accounted for.
|
|
* Mark the codetag as empty to avoid accounting error
|
|
* when the page is freed by unpoison_memory().
|
|
*/
|
|
clear_page_tag_ref(page);
|
|
return false;
|
|
}
|
|
|
|
VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
|
|
|
|
/*
|
|
* Check tail pages before head page information is cleared to
|
|
* avoid checking PageCompound for order-0 pages.
|
|
*/
|
|
if (unlikely(order)) {
|
|
int i;
|
|
|
|
if (compound)
|
|
page[1].flags &= ~PAGE_FLAGS_SECOND;
|
|
for (i = 1; i < (1 << order); i++) {
|
|
if (compound)
|
|
bad += free_tail_page_prepare(page, page + i);
|
|
if (is_check_pages_enabled()) {
|
|
if (free_page_is_bad(page + i)) {
|
|
bad++;
|
|
continue;
|
|
}
|
|
}
|
|
(page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
|
|
}
|
|
}
|
|
if (PageMappingFlags(page)) {
|
|
if (PageAnon(page))
|
|
mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1);
|
|
page->mapping = NULL;
|
|
}
|
|
if (is_check_pages_enabled()) {
|
|
if (free_page_is_bad(page))
|
|
bad++;
|
|
if (bad)
|
|
return false;
|
|
}
|
|
|
|
page_cpupid_reset_last(page);
|
|
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
|
|
reset_page_owner(page, order);
|
|
page_table_check_free(page, order);
|
|
pgalloc_tag_sub(page, 1 << order);
|
|
|
|
if (!PageHighMem(page)) {
|
|
debug_check_no_locks_freed(page_address(page),
|
|
PAGE_SIZE << order);
|
|
debug_check_no_obj_freed(page_address(page),
|
|
PAGE_SIZE << order);
|
|
}
|
|
|
|
kernel_poison_pages(page, 1 << order);
|
|
|
|
/*
|
|
* As memory initialization might be integrated into KASAN,
|
|
* KASAN poisoning and memory initialization code must be
|
|
* kept together to avoid discrepancies in behavior.
|
|
*
|
|
* With hardware tag-based KASAN, memory tags must be set before the
|
|
* page becomes unavailable via debug_pagealloc or arch_free_page.
|
|
*/
|
|
if (!skip_kasan_poison) {
|
|
kasan_poison_pages(page, order, init);
|
|
|
|
/* Memory is already initialized if KASAN did it internally. */
|
|
if (kasan_has_integrated_init())
|
|
init = false;
|
|
}
|
|
if (init)
|
|
kernel_init_pages(page, 1 << order);
|
|
|
|
/*
|
|
* arch_free_page() can make the page's contents inaccessible. s390
|
|
* does this. So nothing which can access the page's contents should
|
|
* happen after this.
|
|
*/
|
|
arch_free_page(page, order);
|
|
|
|
debug_pagealloc_unmap_pages(page, 1 << order);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Frees a number of pages from the PCP lists
|
|
* Assumes all pages on list are in same zone.
|
|
* count is the number of pages to free.
|
|
*/
|
|
static void free_pcppages_bulk(struct zone *zone, int count,
|
|
struct per_cpu_pages *pcp,
|
|
int pindex)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int order;
|
|
struct page *page;
|
|
|
|
/*
|
|
* Ensure proper count is passed which otherwise would stuck in the
|
|
* below while (list_empty(list)) loop.
|
|
*/
|
|
count = min(pcp->count, count);
|
|
|
|
/* Ensure requested pindex is drained first. */
|
|
pindex = pindex - 1;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
|
|
while (count > 0) {
|
|
struct list_head *list;
|
|
int nr_pages;
|
|
|
|
/* Remove pages from lists in a round-robin fashion. */
|
|
do {
|
|
if (++pindex > NR_PCP_LISTS - 1)
|
|
pindex = 0;
|
|
list = &pcp->lists[pindex];
|
|
} while (list_empty(list));
|
|
|
|
order = pindex_to_order(pindex);
|
|
nr_pages = 1 << order;
|
|
do {
|
|
unsigned long pfn;
|
|
int mt;
|
|
|
|
page = list_last_entry(list, struct page, pcp_list);
|
|
pfn = page_to_pfn(page);
|
|
mt = get_pfnblock_migratetype(page, pfn);
|
|
|
|
/* must delete to avoid corrupting pcp list */
|
|
list_del(&page->pcp_list);
|
|
count -= nr_pages;
|
|
pcp->count -= nr_pages;
|
|
|
|
__free_one_page(page, pfn, zone, order, mt, FPI_NONE);
|
|
trace_mm_page_pcpu_drain(page, order, mt);
|
|
} while (count > 0 && !list_empty(list));
|
|
}
|
|
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
|
|
/* Split a multi-block free page into its individual pageblocks. */
|
|
static void split_large_buddy(struct zone *zone, struct page *page,
|
|
unsigned long pfn, int order, fpi_t fpi)
|
|
{
|
|
unsigned long end = pfn + (1 << order);
|
|
|
|
VM_WARN_ON_ONCE(!IS_ALIGNED(pfn, 1 << order));
|
|
/* Caller removed page from freelist, buddy info cleared! */
|
|
VM_WARN_ON_ONCE(PageBuddy(page));
|
|
|
|
if (order > pageblock_order)
|
|
order = pageblock_order;
|
|
|
|
do {
|
|
int mt = get_pfnblock_migratetype(page, pfn);
|
|
|
|
__free_one_page(page, pfn, zone, order, mt, fpi);
|
|
pfn += 1 << order;
|
|
if (pfn == end)
|
|
break;
|
|
page = pfn_to_page(pfn);
|
|
} while (1);
|
|
}
|
|
|
|
static void free_one_page(struct zone *zone, struct page *page,
|
|
unsigned long pfn, unsigned int order,
|
|
fpi_t fpi_flags)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
split_large_buddy(zone, page, pfn, order, fpi_flags);
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
|
|
__count_vm_events(PGFREE, 1 << order);
|
|
}
|
|
|
|
static void __free_pages_ok(struct page *page, unsigned int order,
|
|
fpi_t fpi_flags)
|
|
{
|
|
unsigned long pfn = page_to_pfn(page);
|
|
struct zone *zone = page_zone(page);
|
|
|
|
if (free_pages_prepare(page, order))
|
|
free_one_page(zone, page, pfn, order, fpi_flags);
|
|
}
|
|
|
|
void __meminit __free_pages_core(struct page *page, unsigned int order,
|
|
enum meminit_context context)
|
|
{
|
|
unsigned int nr_pages = 1 << order;
|
|
struct page *p = page;
|
|
unsigned int loop;
|
|
|
|
/*
|
|
* When initializing the memmap, __init_single_page() sets the refcount
|
|
* of all pages to 1 ("allocated"/"not free"). We have to set the
|
|
* refcount of all involved pages to 0.
|
|
*
|
|
* Note that hotplugged memory pages are initialized to PageOffline().
|
|
* Pages freed from memblock might be marked as reserved.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG) &&
|
|
unlikely(context == MEMINIT_HOTPLUG)) {
|
|
for (loop = 0; loop < nr_pages; loop++, p++) {
|
|
VM_WARN_ON_ONCE(PageReserved(p));
|
|
__ClearPageOffline(p);
|
|
set_page_count(p, 0);
|
|
}
|
|
|
|
adjust_managed_page_count(page, nr_pages);
|
|
} else {
|
|
for (loop = 0; loop < nr_pages; loop++, p++) {
|
|
__ClearPageReserved(p);
|
|
set_page_count(p, 0);
|
|
}
|
|
|
|
/* memblock adjusts totalram_pages() manually. */
|
|
atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
|
|
}
|
|
|
|
if (page_contains_unaccepted(page, order)) {
|
|
if (order == MAX_PAGE_ORDER && __free_unaccepted(page))
|
|
return;
|
|
|
|
accept_memory(page_to_phys(page), PAGE_SIZE << order);
|
|
}
|
|
|
|
/*
|
|
* Bypass PCP and place fresh pages right to the tail, primarily
|
|
* relevant for memory onlining.
|
|
*/
|
|
__free_pages_ok(page, order, FPI_TO_TAIL);
|
|
}
|
|
|
|
/*
|
|
* Check that the whole (or subset of) a pageblock given by the interval of
|
|
* [start_pfn, end_pfn) is valid and within the same zone, before scanning it
|
|
* with the migration of free compaction scanner.
|
|
*
|
|
* Return struct page pointer of start_pfn, or NULL if checks were not passed.
|
|
*
|
|
* It's possible on some configurations to have a setup like node0 node1 node0
|
|
* i.e. it's possible that all pages within a zones range of pages do not
|
|
* belong to a single zone. We assume that a border between node0 and node1
|
|
* can occur within a single pageblock, but not a node0 node1 node0
|
|
* interleaving within a single pageblock. It is therefore sufficient to check
|
|
* the first and last page of a pageblock and avoid checking each individual
|
|
* page in a pageblock.
|
|
*
|
|
* Note: the function may return non-NULL struct page even for a page block
|
|
* which contains a memory hole (i.e. there is no physical memory for a subset
|
|
* of the pfn range). For example, if the pageblock order is MAX_PAGE_ORDER, which
|
|
* will fall into 2 sub-sections, and the end pfn of the pageblock may be hole
|
|
* even though the start pfn is online and valid. This should be safe most of
|
|
* the time because struct pages are still initialized via init_unavailable_range()
|
|
* and pfn walkers shouldn't touch any physical memory range for which they do
|
|
* not recognize any specific metadata in struct pages.
|
|
*/
|
|
struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
|
|
unsigned long end_pfn, struct zone *zone)
|
|
{
|
|
struct page *start_page;
|
|
struct page *end_page;
|
|
|
|
/* end_pfn is one past the range we are checking */
|
|
end_pfn--;
|
|
|
|
if (!pfn_valid(end_pfn))
|
|
return NULL;
|
|
|
|
start_page = pfn_to_online_page(start_pfn);
|
|
if (!start_page)
|
|
return NULL;
|
|
|
|
if (page_zone(start_page) != zone)
|
|
return NULL;
|
|
|
|
end_page = pfn_to_page(end_pfn);
|
|
|
|
/* This gives a shorter code than deriving page_zone(end_page) */
|
|
if (page_zone_id(start_page) != page_zone_id(end_page))
|
|
return NULL;
|
|
|
|
return start_page;
|
|
}
|
|
|
|
/*
|
|
* The order of subdivision here is critical for the IO subsystem.
|
|
* Please do not alter this order without good reasons and regression
|
|
* testing. Specifically, as large blocks of memory are subdivided,
|
|
* the order in which smaller blocks are delivered depends on the order
|
|
* they're subdivided in this function. This is the primary factor
|
|
* influencing the order in which pages are delivered to the IO
|
|
* subsystem according to empirical testing, and this is also justified
|
|
* by considering the behavior of a buddy system containing a single
|
|
* large block of memory acted on by a series of small allocations.
|
|
* This behavior is a critical factor in sglist merging's success.
|
|
*
|
|
* -- nyc
|
|
*/
|
|
static inline unsigned int expand(struct zone *zone, struct page *page, int low,
|
|
int high, int migratetype)
|
|
{
|
|
unsigned int size = 1 << high;
|
|
unsigned int nr_added = 0;
|
|
|
|
while (high > low) {
|
|
high--;
|
|
size >>= 1;
|
|
VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
|
|
|
|
/*
|
|
* Mark as guard pages (or page), that will allow to
|
|
* merge back to allocator when buddy will be freed.
|
|
* Corresponding page table entries will not be touched,
|
|
* pages will stay not present in virtual address space
|
|
*/
|
|
if (set_page_guard(zone, &page[size], high))
|
|
continue;
|
|
|
|
__add_to_free_list(&page[size], zone, high, migratetype, false);
|
|
set_buddy_order(&page[size], high);
|
|
nr_added += size;
|
|
}
|
|
|
|
return nr_added;
|
|
}
|
|
|
|
static __always_inline void page_del_and_expand(struct zone *zone,
|
|
struct page *page, int low,
|
|
int high, int migratetype)
|
|
{
|
|
int nr_pages = 1 << high;
|
|
|
|
__del_page_from_free_list(page, zone, high, migratetype);
|
|
nr_pages -= expand(zone, page, low, high, migratetype);
|
|
account_freepages(zone, -nr_pages, migratetype);
|
|
}
|
|
|
|
static void check_new_page_bad(struct page *page)
|
|
{
|
|
if (unlikely(page->flags & __PG_HWPOISON)) {
|
|
/* Don't complain about hwpoisoned pages */
|
|
if (PageBuddy(page))
|
|
__ClearPageBuddy(page);
|
|
return;
|
|
}
|
|
|
|
bad_page(page,
|
|
page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
|
|
}
|
|
|
|
/*
|
|
* This page is about to be returned from the page allocator
|
|
*/
|
|
static bool check_new_page(struct page *page)
|
|
{
|
|
if (likely(page_expected_state(page,
|
|
PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
|
|
return false;
|
|
|
|
check_new_page_bad(page);
|
|
return true;
|
|
}
|
|
|
|
static inline bool check_new_pages(struct page *page, unsigned int order)
|
|
{
|
|
if (is_check_pages_enabled()) {
|
|
for (int i = 0; i < (1 << order); i++) {
|
|
struct page *p = page + i;
|
|
|
|
if (check_new_page(p))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool should_skip_kasan_unpoison(gfp_t flags)
|
|
{
|
|
/* Don't skip if a software KASAN mode is enabled. */
|
|
if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
|
|
IS_ENABLED(CONFIG_KASAN_SW_TAGS))
|
|
return false;
|
|
|
|
/* Skip, if hardware tag-based KASAN is not enabled. */
|
|
if (!kasan_hw_tags_enabled())
|
|
return true;
|
|
|
|
/*
|
|
* With hardware tag-based KASAN enabled, skip if this has been
|
|
* requested via __GFP_SKIP_KASAN.
|
|
*/
|
|
return flags & __GFP_SKIP_KASAN;
|
|
}
|
|
|
|
static inline bool should_skip_init(gfp_t flags)
|
|
{
|
|
/* Don't skip, if hardware tag-based KASAN is not enabled. */
|
|
if (!kasan_hw_tags_enabled())
|
|
return false;
|
|
|
|
/* For hardware tag-based KASAN, skip if requested. */
|
|
return (flags & __GFP_SKIP_ZERO);
|
|
}
|
|
|
|
inline void post_alloc_hook(struct page *page, unsigned int order,
|
|
gfp_t gfp_flags)
|
|
{
|
|
bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags) &&
|
|
!should_skip_init(gfp_flags);
|
|
bool zero_tags = init && (gfp_flags & __GFP_ZEROTAGS);
|
|
int i;
|
|
|
|
set_page_private(page, 0);
|
|
|
|
arch_alloc_page(page, order);
|
|
debug_pagealloc_map_pages(page, 1 << order);
|
|
|
|
/*
|
|
* Page unpoisoning must happen before memory initialization.
|
|
* Otherwise, the poison pattern will be overwritten for __GFP_ZERO
|
|
* allocations and the page unpoisoning code will complain.
|
|
*/
|
|
kernel_unpoison_pages(page, 1 << order);
|
|
|
|
/*
|
|
* As memory initialization might be integrated into KASAN,
|
|
* KASAN unpoisoning and memory initializion code must be
|
|
* kept together to avoid discrepancies in behavior.
|
|
*/
|
|
|
|
/*
|
|
* If memory tags should be zeroed
|
|
* (which happens only when memory should be initialized as well).
|
|
*/
|
|
if (zero_tags) {
|
|
/* Initialize both memory and memory tags. */
|
|
for (i = 0; i != 1 << order; ++i)
|
|
tag_clear_highpage(page + i);
|
|
|
|
/* Take note that memory was initialized by the loop above. */
|
|
init = false;
|
|
}
|
|
if (!should_skip_kasan_unpoison(gfp_flags) &&
|
|
kasan_unpoison_pages(page, order, init)) {
|
|
/* Take note that memory was initialized by KASAN. */
|
|
if (kasan_has_integrated_init())
|
|
init = false;
|
|
} else {
|
|
/*
|
|
* If memory tags have not been set by KASAN, reset the page
|
|
* tags to ensure page_address() dereferencing does not fault.
|
|
*/
|
|
for (i = 0; i != 1 << order; ++i)
|
|
page_kasan_tag_reset(page + i);
|
|
}
|
|
/* If memory is still not initialized, initialize it now. */
|
|
if (init)
|
|
kernel_init_pages(page, 1 << order);
|
|
|
|
set_page_owner(page, order, gfp_flags);
|
|
page_table_check_alloc(page, order);
|
|
pgalloc_tag_add(page, current, 1 << order);
|
|
}
|
|
|
|
static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
|
|
unsigned int alloc_flags)
|
|
{
|
|
post_alloc_hook(page, order, gfp_flags);
|
|
|
|
if (order && (gfp_flags & __GFP_COMP))
|
|
prep_compound_page(page, order);
|
|
|
|
/*
|
|
* page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
|
|
* allocate the page. The expectation is that the caller is taking
|
|
* steps that will free more memory. The caller should avoid the page
|
|
* being used for !PFMEMALLOC purposes.
|
|
*/
|
|
if (alloc_flags & ALLOC_NO_WATERMARKS)
|
|
set_page_pfmemalloc(page);
|
|
else
|
|
clear_page_pfmemalloc(page);
|
|
}
|
|
|
|
/*
|
|
* Go through the free lists for the given migratetype and remove
|
|
* the smallest available page from the freelists
|
|
*/
|
|
static __always_inline
|
|
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
|
|
int migratetype)
|
|
{
|
|
unsigned int current_order;
|
|
struct free_area *area;
|
|
struct page *page;
|
|
|
|
/* Find a page of the appropriate size in the preferred list */
|
|
for (current_order = order; current_order < NR_PAGE_ORDERS; ++current_order) {
|
|
area = &(zone->free_area[current_order]);
|
|
page = get_page_from_free_area(area, migratetype);
|
|
if (!page)
|
|
continue;
|
|
|
|
page_del_and_expand(zone, page, order, current_order,
|
|
migratetype);
|
|
trace_mm_page_alloc_zone_locked(page, order, migratetype,
|
|
pcp_allowed_order(order) &&
|
|
migratetype < MIGRATE_PCPTYPES);
|
|
return page;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* This array describes the order lists are fallen back to when
|
|
* the free lists for the desirable migrate type are depleted
|
|
*
|
|
* The other migratetypes do not have fallbacks.
|
|
*/
|
|
static int fallbacks[MIGRATE_PCPTYPES][MIGRATE_PCPTYPES - 1] = {
|
|
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE },
|
|
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE },
|
|
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE },
|
|
};
|
|
|
|
#ifdef CONFIG_CMA
|
|
static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
|
|
unsigned int order)
|
|
{
|
|
return __rmqueue_smallest(zone, order, MIGRATE_CMA);
|
|
}
|
|
#else
|
|
static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
|
|
unsigned int order) { return NULL; }
|
|
#endif
|
|
|
|
/*
|
|
* Change the type of a block and move all its free pages to that
|
|
* type's freelist.
|
|
*/
|
|
static int __move_freepages_block(struct zone *zone, unsigned long start_pfn,
|
|
int old_mt, int new_mt)
|
|
{
|
|
struct page *page;
|
|
unsigned long pfn, end_pfn;
|
|
unsigned int order;
|
|
int pages_moved = 0;
|
|
|
|
VM_WARN_ON(start_pfn & (pageblock_nr_pages - 1));
|
|
end_pfn = pageblock_end_pfn(start_pfn);
|
|
|
|
for (pfn = start_pfn; pfn < end_pfn;) {
|
|
page = pfn_to_page(pfn);
|
|
if (!PageBuddy(page)) {
|
|
pfn++;
|
|
continue;
|
|
}
|
|
|
|
/* Make sure we are not inadvertently changing nodes */
|
|
VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
|
|
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
|
|
|
|
order = buddy_order(page);
|
|
|
|
move_to_free_list(page, zone, order, old_mt, new_mt);
|
|
|
|
pfn += 1 << order;
|
|
pages_moved += 1 << order;
|
|
}
|
|
|
|
set_pageblock_migratetype(pfn_to_page(start_pfn), new_mt);
|
|
|
|
return pages_moved;
|
|
}
|
|
|
|
static bool prep_move_freepages_block(struct zone *zone, struct page *page,
|
|
unsigned long *start_pfn,
|
|
int *num_free, int *num_movable)
|
|
{
|
|
unsigned long pfn, start, end;
|
|
|
|
pfn = page_to_pfn(page);
|
|
start = pageblock_start_pfn(pfn);
|
|
end = pageblock_end_pfn(pfn);
|
|
|
|
/*
|
|
* The caller only has the lock for @zone, don't touch ranges
|
|
* that straddle into other zones. While we could move part of
|
|
* the range that's inside the zone, this call is usually
|
|
* accompanied by other operations such as migratetype updates
|
|
* which also should be locked.
|
|
*/
|
|
if (!zone_spans_pfn(zone, start))
|
|
return false;
|
|
if (!zone_spans_pfn(zone, end - 1))
|
|
return false;
|
|
|
|
*start_pfn = start;
|
|
|
|
if (num_free) {
|
|
*num_free = 0;
|
|
*num_movable = 0;
|
|
for (pfn = start; pfn < end;) {
|
|
page = pfn_to_page(pfn);
|
|
if (PageBuddy(page)) {
|
|
int nr = 1 << buddy_order(page);
|
|
|
|
*num_free += nr;
|
|
pfn += nr;
|
|
continue;
|
|
}
|
|
/*
|
|
* We assume that pages that could be isolated for
|
|
* migration are movable. But we don't actually try
|
|
* isolating, as that would be expensive.
|
|
*/
|
|
if (PageLRU(page) || __PageMovable(page))
|
|
(*num_movable)++;
|
|
pfn++;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int move_freepages_block(struct zone *zone, struct page *page,
|
|
int old_mt, int new_mt)
|
|
{
|
|
unsigned long start_pfn;
|
|
|
|
if (!prep_move_freepages_block(zone, page, &start_pfn, NULL, NULL))
|
|
return -1;
|
|
|
|
return __move_freepages_block(zone, start_pfn, old_mt, new_mt);
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_ISOLATION
|
|
/* Look for a buddy that straddles start_pfn */
|
|
static unsigned long find_large_buddy(unsigned long start_pfn)
|
|
{
|
|
int order = 0;
|
|
struct page *page;
|
|
unsigned long pfn = start_pfn;
|
|
|
|
while (!PageBuddy(page = pfn_to_page(pfn))) {
|
|
/* Nothing found */
|
|
if (++order > MAX_PAGE_ORDER)
|
|
return start_pfn;
|
|
pfn &= ~0UL << order;
|
|
}
|
|
|
|
/*
|
|
* Found a preceding buddy, but does it straddle?
|
|
*/
|
|
if (pfn + (1 << buddy_order(page)) > start_pfn)
|
|
return pfn;
|
|
|
|
/* Nothing found */
|
|
return start_pfn;
|
|
}
|
|
|
|
/**
|
|
* move_freepages_block_isolate - move free pages in block for page isolation
|
|
* @zone: the zone
|
|
* @page: the pageblock page
|
|
* @migratetype: migratetype to set on the pageblock
|
|
*
|
|
* This is similar to move_freepages_block(), but handles the special
|
|
* case encountered in page isolation, where the block of interest
|
|
* might be part of a larger buddy spanning multiple pageblocks.
|
|
*
|
|
* Unlike the regular page allocator path, which moves pages while
|
|
* stealing buddies off the freelist, page isolation is interested in
|
|
* arbitrary pfn ranges that may have overlapping buddies on both ends.
|
|
*
|
|
* This function handles that. Straddling buddies are split into
|
|
* individual pageblocks. Only the block of interest is moved.
|
|
*
|
|
* Returns %true if pages could be moved, %false otherwise.
|
|
*/
|
|
bool move_freepages_block_isolate(struct zone *zone, struct page *page,
|
|
int migratetype)
|
|
{
|
|
unsigned long start_pfn, pfn;
|
|
|
|
if (!prep_move_freepages_block(zone, page, &start_pfn, NULL, NULL))
|
|
return false;
|
|
|
|
/* No splits needed if buddies can't span multiple blocks */
|
|
if (pageblock_order == MAX_PAGE_ORDER)
|
|
goto move;
|
|
|
|
/* We're a tail block in a larger buddy */
|
|
pfn = find_large_buddy(start_pfn);
|
|
if (pfn != start_pfn) {
|
|
struct page *buddy = pfn_to_page(pfn);
|
|
int order = buddy_order(buddy);
|
|
|
|
del_page_from_free_list(buddy, zone, order,
|
|
get_pfnblock_migratetype(buddy, pfn));
|
|
set_pageblock_migratetype(page, migratetype);
|
|
split_large_buddy(zone, buddy, pfn, order, FPI_NONE);
|
|
return true;
|
|
}
|
|
|
|
/* We're the starting block of a larger buddy */
|
|
if (PageBuddy(page) && buddy_order(page) > pageblock_order) {
|
|
int order = buddy_order(page);
|
|
|
|
del_page_from_free_list(page, zone, order,
|
|
get_pfnblock_migratetype(page, pfn));
|
|
set_pageblock_migratetype(page, migratetype);
|
|
split_large_buddy(zone, page, pfn, order, FPI_NONE);
|
|
return true;
|
|
}
|
|
move:
|
|
__move_freepages_block(zone, start_pfn,
|
|
get_pfnblock_migratetype(page, start_pfn),
|
|
migratetype);
|
|
return true;
|
|
}
|
|
#endif /* CONFIG_MEMORY_ISOLATION */
|
|
|
|
static void change_pageblock_range(struct page *pageblock_page,
|
|
int start_order, int migratetype)
|
|
{
|
|
int nr_pageblocks = 1 << (start_order - pageblock_order);
|
|
|
|
while (nr_pageblocks--) {
|
|
set_pageblock_migratetype(pageblock_page, migratetype);
|
|
pageblock_page += pageblock_nr_pages;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* When we are falling back to another migratetype during allocation, try to
|
|
* steal extra free pages from the same pageblocks to satisfy further
|
|
* allocations, instead of polluting multiple pageblocks.
|
|
*
|
|
* If we are stealing a relatively large buddy page, it is likely there will
|
|
* be more free pages in the pageblock, so try to steal them all. For
|
|
* reclaimable and unmovable allocations, we steal regardless of page size,
|
|
* as fragmentation caused by those allocations polluting movable pageblocks
|
|
* is worse than movable allocations stealing from unmovable and reclaimable
|
|
* pageblocks.
|
|
*/
|
|
static bool can_steal_fallback(unsigned int order, int start_mt)
|
|
{
|
|
/*
|
|
* Leaving this order check is intended, although there is
|
|
* relaxed order check in next check. The reason is that
|
|
* we can actually steal whole pageblock if this condition met,
|
|
* but, below check doesn't guarantee it and that is just heuristic
|
|
* so could be changed anytime.
|
|
*/
|
|
if (order >= pageblock_order)
|
|
return true;
|
|
|
|
/*
|
|
* Movable pages won't cause permanent fragmentation, so when you alloc
|
|
* small pages, you just need to temporarily steal unmovable or
|
|
* reclaimable pages that are closest to the request size. After a
|
|
* while, memory compaction may occur to form large contiguous pages,
|
|
* and the next movable allocation may not need to steal. Unmovable and
|
|
* reclaimable allocations need to actually steal pages.
|
|
*/
|
|
if (order >= pageblock_order / 2 ||
|
|
start_mt == MIGRATE_RECLAIMABLE ||
|
|
start_mt == MIGRATE_UNMOVABLE ||
|
|
page_group_by_mobility_disabled)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool boost_watermark(struct zone *zone)
|
|
{
|
|
unsigned long max_boost;
|
|
|
|
if (!watermark_boost_factor)
|
|
return false;
|
|
/*
|
|
* Don't bother in zones that are unlikely to produce results.
|
|
* On small machines, including kdump capture kernels running
|
|
* in a small area, boosting the watermark can cause an out of
|
|
* memory situation immediately.
|
|
*/
|
|
if ((pageblock_nr_pages * 4) > zone_managed_pages(zone))
|
|
return false;
|
|
|
|
max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
|
|
watermark_boost_factor, 10000);
|
|
|
|
/*
|
|
* high watermark may be uninitialised if fragmentation occurs
|
|
* very early in boot so do not boost. We do not fall
|
|
* through and boost by pageblock_nr_pages as failing
|
|
* allocations that early means that reclaim is not going
|
|
* to help and it may even be impossible to reclaim the
|
|
* boosted watermark resulting in a hang.
|
|
*/
|
|
if (!max_boost)
|
|
return false;
|
|
|
|
max_boost = max(pageblock_nr_pages, max_boost);
|
|
|
|
zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
|
|
max_boost);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* This function implements actual steal behaviour. If order is large enough, we
|
|
* can claim the whole pageblock for the requested migratetype. If not, we check
|
|
* the pageblock for constituent pages; if at least half of the pages are free
|
|
* or compatible, we can still claim the whole block, so pages freed in the
|
|
* future will be put on the correct free list. Otherwise, we isolate exactly
|
|
* the order we need from the fallback block and leave its migratetype alone.
|
|
*/
|
|
static struct page *
|
|
steal_suitable_fallback(struct zone *zone, struct page *page,
|
|
int current_order, int order, int start_type,
|
|
unsigned int alloc_flags, bool whole_block)
|
|
{
|
|
int free_pages, movable_pages, alike_pages;
|
|
unsigned long start_pfn;
|
|
int block_type;
|
|
|
|
block_type = get_pageblock_migratetype(page);
|
|
|
|
/*
|
|
* This can happen due to races and we want to prevent broken
|
|
* highatomic accounting.
|
|
*/
|
|
if (is_migrate_highatomic(block_type))
|
|
goto single_page;
|
|
|
|
/* Take ownership for orders >= pageblock_order */
|
|
if (current_order >= pageblock_order) {
|
|
unsigned int nr_added;
|
|
|
|
del_page_from_free_list(page, zone, current_order, block_type);
|
|
change_pageblock_range(page, current_order, start_type);
|
|
nr_added = expand(zone, page, order, current_order, start_type);
|
|
account_freepages(zone, nr_added, start_type);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Boost watermarks to increase reclaim pressure to reduce the
|
|
* likelihood of future fallbacks. Wake kswapd now as the node
|
|
* may be balanced overall and kswapd will not wake naturally.
|
|
*/
|
|
if (boost_watermark(zone) && (alloc_flags & ALLOC_KSWAPD))
|
|
set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
|
|
|
|
/* We are not allowed to try stealing from the whole block */
|
|
if (!whole_block)
|
|
goto single_page;
|
|
|
|
/* moving whole block can fail due to zone boundary conditions */
|
|
if (!prep_move_freepages_block(zone, page, &start_pfn, &free_pages,
|
|
&movable_pages))
|
|
goto single_page;
|
|
|
|
/*
|
|
* Determine how many pages are compatible with our allocation.
|
|
* For movable allocation, it's the number of movable pages which
|
|
* we just obtained. For other types it's a bit more tricky.
|
|
*/
|
|
if (start_type == MIGRATE_MOVABLE) {
|
|
alike_pages = movable_pages;
|
|
} else {
|
|
/*
|
|
* If we are falling back a RECLAIMABLE or UNMOVABLE allocation
|
|
* to MOVABLE pageblock, consider all non-movable pages as
|
|
* compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
|
|
* vice versa, be conservative since we can't distinguish the
|
|
* exact migratetype of non-movable pages.
|
|
*/
|
|
if (block_type == MIGRATE_MOVABLE)
|
|
alike_pages = pageblock_nr_pages
|
|
- (free_pages + movable_pages);
|
|
else
|
|
alike_pages = 0;
|
|
}
|
|
/*
|
|
* If a sufficient number of pages in the block are either free or of
|
|
* compatible migratability as our allocation, claim the whole block.
|
|
*/
|
|
if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
|
|
page_group_by_mobility_disabled) {
|
|
__move_freepages_block(zone, start_pfn, block_type, start_type);
|
|
return __rmqueue_smallest(zone, order, start_type);
|
|
}
|
|
|
|
single_page:
|
|
page_del_and_expand(zone, page, order, current_order, block_type);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Check whether there is a suitable fallback freepage with requested order.
|
|
* If only_stealable is true, this function returns fallback_mt only if
|
|
* we can steal other freepages all together. This would help to reduce
|
|
* fragmentation due to mixed migratetype pages in one pageblock.
|
|
*/
|
|
int find_suitable_fallback(struct free_area *area, unsigned int order,
|
|
int migratetype, bool only_stealable, bool *can_steal)
|
|
{
|
|
int i;
|
|
int fallback_mt;
|
|
|
|
if (area->nr_free == 0)
|
|
return -1;
|
|
|
|
*can_steal = false;
|
|
for (i = 0; i < MIGRATE_PCPTYPES - 1 ; i++) {
|
|
fallback_mt = fallbacks[migratetype][i];
|
|
if (free_area_empty(area, fallback_mt))
|
|
continue;
|
|
|
|
if (can_steal_fallback(order, migratetype))
|
|
*can_steal = true;
|
|
|
|
if (!only_stealable)
|
|
return fallback_mt;
|
|
|
|
if (*can_steal)
|
|
return fallback_mt;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Reserve the pageblock(s) surrounding an allocation request for
|
|
* exclusive use of high-order atomic allocations if there are no
|
|
* empty page blocks that contain a page with a suitable order
|
|
*/
|
|
static void reserve_highatomic_pageblock(struct page *page, int order,
|
|
struct zone *zone)
|
|
{
|
|
int mt;
|
|
unsigned long max_managed, flags;
|
|
|
|
/*
|
|
* The number reserved as: minimum is 1 pageblock, maximum is
|
|
* roughly 1% of a zone. But if 1% of a zone falls below a
|
|
* pageblock size, then don't reserve any pageblocks.
|
|
* Check is race-prone but harmless.
|
|
*/
|
|
if ((zone_managed_pages(zone) / 100) < pageblock_nr_pages)
|
|
return;
|
|
max_managed = ALIGN((zone_managed_pages(zone) / 100), pageblock_nr_pages);
|
|
if (zone->nr_reserved_highatomic >= max_managed)
|
|
return;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
|
|
/* Recheck the nr_reserved_highatomic limit under the lock */
|
|
if (zone->nr_reserved_highatomic >= max_managed)
|
|
goto out_unlock;
|
|
|
|
/* Yoink! */
|
|
mt = get_pageblock_migratetype(page);
|
|
/* Only reserve normal pageblocks (i.e., they can merge with others) */
|
|
if (!migratetype_is_mergeable(mt))
|
|
goto out_unlock;
|
|
|
|
if (order < pageblock_order) {
|
|
if (move_freepages_block(zone, page, mt, MIGRATE_HIGHATOMIC) == -1)
|
|
goto out_unlock;
|
|
zone->nr_reserved_highatomic += pageblock_nr_pages;
|
|
} else {
|
|
change_pageblock_range(page, order, MIGRATE_HIGHATOMIC);
|
|
zone->nr_reserved_highatomic += 1 << order;
|
|
}
|
|
|
|
out_unlock:
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
|
|
/*
|
|
* Used when an allocation is about to fail under memory pressure. This
|
|
* potentially hurts the reliability of high-order allocations when under
|
|
* intense memory pressure but failed atomic allocations should be easier
|
|
* to recover from than an OOM.
|
|
*
|
|
* If @force is true, try to unreserve pageblocks even though highatomic
|
|
* pageblock is exhausted.
|
|
*/
|
|
static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
|
|
bool force)
|
|
{
|
|
struct zonelist *zonelist = ac->zonelist;
|
|
unsigned long flags;
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
struct page *page;
|
|
int order;
|
|
int ret;
|
|
|
|
for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
|
|
ac->nodemask) {
|
|
/*
|
|
* Preserve at least one pageblock unless memory pressure
|
|
* is really high.
|
|
*/
|
|
if (!force && zone->nr_reserved_highatomic <=
|
|
pageblock_nr_pages)
|
|
continue;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
for (order = 0; order < NR_PAGE_ORDERS; order++) {
|
|
struct free_area *area = &(zone->free_area[order]);
|
|
int mt;
|
|
|
|
page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
|
|
if (!page)
|
|
continue;
|
|
|
|
mt = get_pageblock_migratetype(page);
|
|
/*
|
|
* In page freeing path, migratetype change is racy so
|
|
* we can counter several free pages in a pageblock
|
|
* in this loop although we changed the pageblock type
|
|
* from highatomic to ac->migratetype. So we should
|
|
* adjust the count once.
|
|
*/
|
|
if (is_migrate_highatomic(mt)) {
|
|
unsigned long size;
|
|
/*
|
|
* It should never happen but changes to
|
|
* locking could inadvertently allow a per-cpu
|
|
* drain to add pages to MIGRATE_HIGHATOMIC
|
|
* while unreserving so be safe and watch for
|
|
* underflows.
|
|
*/
|
|
size = max(pageblock_nr_pages, 1UL << order);
|
|
size = min(size, zone->nr_reserved_highatomic);
|
|
zone->nr_reserved_highatomic -= size;
|
|
}
|
|
|
|
/*
|
|
* Convert to ac->migratetype and avoid the normal
|
|
* pageblock stealing heuristics. Minimally, the caller
|
|
* is doing the work and needs the pages. More
|
|
* importantly, if the block was always converted to
|
|
* MIGRATE_UNMOVABLE or another type then the number
|
|
* of pageblocks that cannot be completely freed
|
|
* may increase.
|
|
*/
|
|
if (order < pageblock_order)
|
|
ret = move_freepages_block(zone, page, mt,
|
|
ac->migratetype);
|
|
else {
|
|
move_to_free_list(page, zone, order, mt,
|
|
ac->migratetype);
|
|
change_pageblock_range(page, order,
|
|
ac->migratetype);
|
|
ret = 1;
|
|
}
|
|
/*
|
|
* Reserving the block(s) already succeeded,
|
|
* so this should not fail on zone boundaries.
|
|
*/
|
|
WARN_ON_ONCE(ret == -1);
|
|
if (ret > 0) {
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
return ret;
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Try finding a free buddy page on the fallback list and put it on the free
|
|
* list of requested migratetype, possibly along with other pages from the same
|
|
* block, depending on fragmentation avoidance heuristics. Returns true if
|
|
* fallback was found so that __rmqueue_smallest() can grab it.
|
|
*
|
|
* The use of signed ints for order and current_order is a deliberate
|
|
* deviation from the rest of this file, to make the for loop
|
|
* condition simpler.
|
|
*/
|
|
static __always_inline struct page *
|
|
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
|
|
unsigned int alloc_flags)
|
|
{
|
|
struct free_area *area;
|
|
int current_order;
|
|
int min_order = order;
|
|
struct page *page;
|
|
int fallback_mt;
|
|
bool can_steal;
|
|
|
|
/*
|
|
* Do not steal pages from freelists belonging to other pageblocks
|
|
* i.e. orders < pageblock_order. If there are no local zones free,
|
|
* the zonelists will be reiterated without ALLOC_NOFRAGMENT.
|
|
*/
|
|
if (order < pageblock_order && alloc_flags & ALLOC_NOFRAGMENT)
|
|
min_order = pageblock_order;
|
|
|
|
/*
|
|
* Find the largest available free page in the other list. This roughly
|
|
* approximates finding the pageblock with the most free pages, which
|
|
* would be too costly to do exactly.
|
|
*/
|
|
for (current_order = MAX_PAGE_ORDER; current_order >= min_order;
|
|
--current_order) {
|
|
area = &(zone->free_area[current_order]);
|
|
fallback_mt = find_suitable_fallback(area, current_order,
|
|
start_migratetype, false, &can_steal);
|
|
if (fallback_mt == -1)
|
|
continue;
|
|
|
|
/*
|
|
* We cannot steal all free pages from the pageblock and the
|
|
* requested migratetype is movable. In that case it's better to
|
|
* steal and split the smallest available page instead of the
|
|
* largest available page, because even if the next movable
|
|
* allocation falls back into a different pageblock than this
|
|
* one, it won't cause permanent fragmentation.
|
|
*/
|
|
if (!can_steal && start_migratetype == MIGRATE_MOVABLE
|
|
&& current_order > order)
|
|
goto find_smallest;
|
|
|
|
goto do_steal;
|
|
}
|
|
|
|
return NULL;
|
|
|
|
find_smallest:
|
|
for (current_order = order; current_order < NR_PAGE_ORDERS; current_order++) {
|
|
area = &(zone->free_area[current_order]);
|
|
fallback_mt = find_suitable_fallback(area, current_order,
|
|
start_migratetype, false, &can_steal);
|
|
if (fallback_mt != -1)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* This should not happen - we already found a suitable fallback
|
|
* when looking for the largest page.
|
|
*/
|
|
VM_BUG_ON(current_order > MAX_PAGE_ORDER);
|
|
|
|
do_steal:
|
|
page = get_page_from_free_area(area, fallback_mt);
|
|
|
|
/* take off list, maybe claim block, expand remainder */
|
|
page = steal_suitable_fallback(zone, page, current_order, order,
|
|
start_migratetype, alloc_flags, can_steal);
|
|
|
|
trace_mm_page_alloc_extfrag(page, order, current_order,
|
|
start_migratetype, fallback_mt);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Do the hard work of removing an element from the buddy allocator.
|
|
* Call me with the zone->lock already held.
|
|
*/
|
|
static __always_inline struct page *
|
|
__rmqueue(struct zone *zone, unsigned int order, int migratetype,
|
|
unsigned int alloc_flags)
|
|
{
|
|
struct page *page;
|
|
|
|
if (IS_ENABLED(CONFIG_CMA)) {
|
|
/*
|
|
* Balance movable allocations between regular and CMA areas by
|
|
* allocating from CMA when over half of the zone's free memory
|
|
* is in the CMA area.
|
|
*/
|
|
if (alloc_flags & ALLOC_CMA &&
|
|
zone_page_state(zone, NR_FREE_CMA_PAGES) >
|
|
zone_page_state(zone, NR_FREE_PAGES) / 2) {
|
|
page = __rmqueue_cma_fallback(zone, order);
|
|
if (page)
|
|
return page;
|
|
}
|
|
}
|
|
|
|
page = __rmqueue_smallest(zone, order, migratetype);
|
|
if (unlikely(!page)) {
|
|
if (alloc_flags & ALLOC_CMA)
|
|
page = __rmqueue_cma_fallback(zone, order);
|
|
|
|
if (!page)
|
|
page = __rmqueue_fallback(zone, order, migratetype,
|
|
alloc_flags);
|
|
}
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Obtain a specified number of elements from the buddy allocator, all under
|
|
* a single hold of the lock, for efficiency. Add them to the supplied list.
|
|
* Returns the number of new pages which were placed at *list.
|
|
*/
|
|
static int rmqueue_bulk(struct zone *zone, unsigned int order,
|
|
unsigned long count, struct list_head *list,
|
|
int migratetype, unsigned int alloc_flags)
|
|
{
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
for (i = 0; i < count; ++i) {
|
|
struct page *page = __rmqueue(zone, order, migratetype,
|
|
alloc_flags);
|
|
if (unlikely(page == NULL))
|
|
break;
|
|
|
|
/*
|
|
* Split buddy pages returned by expand() are received here in
|
|
* physical page order. The page is added to the tail of
|
|
* caller's list. From the callers perspective, the linked list
|
|
* is ordered by page number under some conditions. This is
|
|
* useful for IO devices that can forward direction from the
|
|
* head, thus also in the physical page order. This is useful
|
|
* for IO devices that can merge IO requests if the physical
|
|
* pages are ordered properly.
|
|
*/
|
|
list_add_tail(&page->pcp_list, list);
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* Called from the vmstat counter updater to decay the PCP high.
|
|
* Return whether there are addition works to do.
|
|
*/
|
|
int decay_pcp_high(struct zone *zone, struct per_cpu_pages *pcp)
|
|
{
|
|
int high_min, to_drain, batch;
|
|
int todo = 0;
|
|
|
|
high_min = READ_ONCE(pcp->high_min);
|
|
batch = READ_ONCE(pcp->batch);
|
|
/*
|
|
* Decrease pcp->high periodically to try to free possible
|
|
* idle PCP pages. And, avoid to free too many pages to
|
|
* control latency. This caps pcp->high decrement too.
|
|
*/
|
|
if (pcp->high > high_min) {
|
|
pcp->high = max3(pcp->count - (batch << CONFIG_PCP_BATCH_SCALE_MAX),
|
|
pcp->high - (pcp->high >> 3), high_min);
|
|
if (pcp->high > high_min)
|
|
todo++;
|
|
}
|
|
|
|
to_drain = pcp->count - pcp->high;
|
|
if (to_drain > 0) {
|
|
spin_lock(&pcp->lock);
|
|
free_pcppages_bulk(zone, to_drain, pcp, 0);
|
|
spin_unlock(&pcp->lock);
|
|
todo++;
|
|
}
|
|
|
|
return todo;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Called from the vmstat counter updater to drain pagesets of this
|
|
* currently executing processor on remote nodes after they have
|
|
* expired.
|
|
*/
|
|
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
|
|
{
|
|
int to_drain, batch;
|
|
|
|
batch = READ_ONCE(pcp->batch);
|
|
to_drain = min(pcp->count, batch);
|
|
if (to_drain > 0) {
|
|
spin_lock(&pcp->lock);
|
|
free_pcppages_bulk(zone, to_drain, pcp, 0);
|
|
spin_unlock(&pcp->lock);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Drain pcplists of the indicated processor and zone.
|
|
*/
|
|
static void drain_pages_zone(unsigned int cpu, struct zone *zone)
|
|
{
|
|
struct per_cpu_pages *pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
|
|
int count;
|
|
|
|
do {
|
|
spin_lock(&pcp->lock);
|
|
count = pcp->count;
|
|
if (count) {
|
|
int to_drain = min(count,
|
|
pcp->batch << CONFIG_PCP_BATCH_SCALE_MAX);
|
|
|
|
free_pcppages_bulk(zone, to_drain, pcp, 0);
|
|
count -= to_drain;
|
|
}
|
|
spin_unlock(&pcp->lock);
|
|
} while (count);
|
|
}
|
|
|
|
/*
|
|
* Drain pcplists of all zones on the indicated processor.
|
|
*/
|
|
static void drain_pages(unsigned int cpu)
|
|
{
|
|
struct zone *zone;
|
|
|
|
for_each_populated_zone(zone) {
|
|
drain_pages_zone(cpu, zone);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Spill all of this CPU's per-cpu pages back into the buddy allocator.
|
|
*/
|
|
void drain_local_pages(struct zone *zone)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
if (zone)
|
|
drain_pages_zone(cpu, zone);
|
|
else
|
|
drain_pages(cpu);
|
|
}
|
|
|
|
/*
|
|
* The implementation of drain_all_pages(), exposing an extra parameter to
|
|
* drain on all cpus.
|
|
*
|
|
* drain_all_pages() is optimized to only execute on cpus where pcplists are
|
|
* not empty. The check for non-emptiness can however race with a free to
|
|
* pcplist that has not yet increased the pcp->count from 0 to 1. Callers
|
|
* that need the guarantee that every CPU has drained can disable the
|
|
* optimizing racy check.
|
|
*/
|
|
static void __drain_all_pages(struct zone *zone, bool force_all_cpus)
|
|
{
|
|
int cpu;
|
|
|
|
/*
|
|
* Allocate in the BSS so we won't require allocation in
|
|
* direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
|
|
*/
|
|
static cpumask_t cpus_with_pcps;
|
|
|
|
/*
|
|
* Do not drain if one is already in progress unless it's specific to
|
|
* a zone. Such callers are primarily CMA and memory hotplug and need
|
|
* the drain to be complete when the call returns.
|
|
*/
|
|
if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
|
|
if (!zone)
|
|
return;
|
|
mutex_lock(&pcpu_drain_mutex);
|
|
}
|
|
|
|
/*
|
|
* We don't care about racing with CPU hotplug event
|
|
* as offline notification will cause the notified
|
|
* cpu to drain that CPU pcps and on_each_cpu_mask
|
|
* disables preemption as part of its processing
|
|
*/
|
|
for_each_online_cpu(cpu) {
|
|
struct per_cpu_pages *pcp;
|
|
struct zone *z;
|
|
bool has_pcps = false;
|
|
|
|
if (force_all_cpus) {
|
|
/*
|
|
* The pcp.count check is racy, some callers need a
|
|
* guarantee that no cpu is missed.
|
|
*/
|
|
has_pcps = true;
|
|
} else if (zone) {
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
|
|
if (pcp->count)
|
|
has_pcps = true;
|
|
} else {
|
|
for_each_populated_zone(z) {
|
|
pcp = per_cpu_ptr(z->per_cpu_pageset, cpu);
|
|
if (pcp->count) {
|
|
has_pcps = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (has_pcps)
|
|
cpumask_set_cpu(cpu, &cpus_with_pcps);
|
|
else
|
|
cpumask_clear_cpu(cpu, &cpus_with_pcps);
|
|
}
|
|
|
|
for_each_cpu(cpu, &cpus_with_pcps) {
|
|
if (zone)
|
|
drain_pages_zone(cpu, zone);
|
|
else
|
|
drain_pages(cpu);
|
|
}
|
|
|
|
mutex_unlock(&pcpu_drain_mutex);
|
|
}
|
|
|
|
/*
|
|
* Spill all the per-cpu pages from all CPUs back into the buddy allocator.
|
|
*
|
|
* When zone parameter is non-NULL, spill just the single zone's pages.
|
|
*/
|
|
void drain_all_pages(struct zone *zone)
|
|
{
|
|
__drain_all_pages(zone, false);
|
|
}
|
|
|
|
static int nr_pcp_free(struct per_cpu_pages *pcp, int batch, int high, bool free_high)
|
|
{
|
|
int min_nr_free, max_nr_free;
|
|
|
|
/* Free as much as possible if batch freeing high-order pages. */
|
|
if (unlikely(free_high))
|
|
return min(pcp->count, batch << CONFIG_PCP_BATCH_SCALE_MAX);
|
|
|
|
/* Check for PCP disabled or boot pageset */
|
|
if (unlikely(high < batch))
|
|
return 1;
|
|
|
|
/* Leave at least pcp->batch pages on the list */
|
|
min_nr_free = batch;
|
|
max_nr_free = high - batch;
|
|
|
|
/*
|
|
* Increase the batch number to the number of the consecutive
|
|
* freed pages to reduce zone lock contention.
|
|
*/
|
|
batch = clamp_t(int, pcp->free_count, min_nr_free, max_nr_free);
|
|
|
|
return batch;
|
|
}
|
|
|
|
static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone,
|
|
int batch, bool free_high)
|
|
{
|
|
int high, high_min, high_max;
|
|
|
|
high_min = READ_ONCE(pcp->high_min);
|
|
high_max = READ_ONCE(pcp->high_max);
|
|
high = pcp->high = clamp(pcp->high, high_min, high_max);
|
|
|
|
if (unlikely(!high))
|
|
return 0;
|
|
|
|
if (unlikely(free_high)) {
|
|
pcp->high = max(high - (batch << CONFIG_PCP_BATCH_SCALE_MAX),
|
|
high_min);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* If reclaim is active, limit the number of pages that can be
|
|
* stored on pcp lists
|
|
*/
|
|
if (test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags)) {
|
|
int free_count = max_t(int, pcp->free_count, batch);
|
|
|
|
pcp->high = max(high - free_count, high_min);
|
|
return min(batch << 2, pcp->high);
|
|
}
|
|
|
|
if (high_min == high_max)
|
|
return high;
|
|
|
|
if (test_bit(ZONE_BELOW_HIGH, &zone->flags)) {
|
|
int free_count = max_t(int, pcp->free_count, batch);
|
|
|
|
pcp->high = max(high - free_count, high_min);
|
|
high = max(pcp->count, high_min);
|
|
} else if (pcp->count >= high) {
|
|
int need_high = pcp->free_count + batch;
|
|
|
|
/* pcp->high should be large enough to hold batch freed pages */
|
|
if (pcp->high < need_high)
|
|
pcp->high = clamp(need_high, high_min, high_max);
|
|
}
|
|
|
|
return high;
|
|
}
|
|
|
|
static void free_frozen_page_commit(struct zone *zone,
|
|
struct per_cpu_pages *pcp, struct page *page, int migratetype,
|
|
unsigned int order)
|
|
{
|
|
int high, batch;
|
|
int pindex;
|
|
bool free_high = false;
|
|
|
|
/*
|
|
* On freeing, reduce the number of pages that are batch allocated.
|
|
* See nr_pcp_alloc() where alloc_factor is increased for subsequent
|
|
* allocations.
|
|
*/
|
|
pcp->alloc_factor >>= 1;
|
|
__count_vm_events(PGFREE, 1 << order);
|
|
pindex = order_to_pindex(migratetype, order);
|
|
list_add(&page->pcp_list, &pcp->lists[pindex]);
|
|
pcp->count += 1 << order;
|
|
|
|
batch = READ_ONCE(pcp->batch);
|
|
/*
|
|
* As high-order pages other than THP's stored on PCP can contribute
|
|
* to fragmentation, limit the number stored when PCP is heavily
|
|
* freeing without allocation. The remainder after bulk freeing
|
|
* stops will be drained from vmstat refresh context.
|
|
*/
|
|
if (order && order <= PAGE_ALLOC_COSTLY_ORDER) {
|
|
free_high = (pcp->free_count >= batch &&
|
|
(pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) &&
|
|
(!(pcp->flags & PCPF_FREE_HIGH_BATCH) ||
|
|
pcp->count >= READ_ONCE(batch)));
|
|
pcp->flags |= PCPF_PREV_FREE_HIGH_ORDER;
|
|
} else if (pcp->flags & PCPF_PREV_FREE_HIGH_ORDER) {
|
|
pcp->flags &= ~PCPF_PREV_FREE_HIGH_ORDER;
|
|
}
|
|
if (pcp->free_count < (batch << CONFIG_PCP_BATCH_SCALE_MAX))
|
|
pcp->free_count += (1 << order);
|
|
high = nr_pcp_high(pcp, zone, batch, free_high);
|
|
if (pcp->count >= high) {
|
|
free_pcppages_bulk(zone, nr_pcp_free(pcp, batch, high, free_high),
|
|
pcp, pindex);
|
|
if (test_bit(ZONE_BELOW_HIGH, &zone->flags) &&
|
|
zone_watermark_ok(zone, 0, high_wmark_pages(zone),
|
|
ZONE_MOVABLE, 0))
|
|
clear_bit(ZONE_BELOW_HIGH, &zone->flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free a pcp page
|
|
*/
|
|
void free_frozen_pages(struct page *page, unsigned int order)
|
|
{
|
|
unsigned long __maybe_unused UP_flags;
|
|
struct per_cpu_pages *pcp;
|
|
struct zone *zone;
|
|
unsigned long pfn = page_to_pfn(page);
|
|
int migratetype;
|
|
|
|
if (!pcp_allowed_order(order)) {
|
|
__free_pages_ok(page, order, FPI_NONE);
|
|
return;
|
|
}
|
|
|
|
if (!free_pages_prepare(page, order))
|
|
return;
|
|
|
|
/*
|
|
* We only track unmovable, reclaimable and movable on pcp lists.
|
|
* Place ISOLATE pages on the isolated list because they are being
|
|
* offlined but treat HIGHATOMIC and CMA as movable pages so we can
|
|
* get those areas back if necessary. Otherwise, we may have to free
|
|
* excessively into the page allocator
|
|
*/
|
|
zone = page_zone(page);
|
|
migratetype = get_pfnblock_migratetype(page, pfn);
|
|
if (unlikely(migratetype >= MIGRATE_PCPTYPES)) {
|
|
if (unlikely(is_migrate_isolate(migratetype))) {
|
|
free_one_page(zone, page, pfn, order, FPI_NONE);
|
|
return;
|
|
}
|
|
migratetype = MIGRATE_MOVABLE;
|
|
}
|
|
|
|
pcp_trylock_prepare(UP_flags);
|
|
pcp = pcp_spin_trylock(zone->per_cpu_pageset);
|
|
if (pcp) {
|
|
free_frozen_page_commit(zone, pcp, page, migratetype, order);
|
|
pcp_spin_unlock(pcp);
|
|
} else {
|
|
free_one_page(zone, page, pfn, order, FPI_NONE);
|
|
}
|
|
pcp_trylock_finish(UP_flags);
|
|
}
|
|
|
|
/*
|
|
* Free a batch of folios
|
|
*/
|
|
void free_unref_folios(struct folio_batch *folios)
|
|
{
|
|
unsigned long __maybe_unused UP_flags;
|
|
struct per_cpu_pages *pcp = NULL;
|
|
struct zone *locked_zone = NULL;
|
|
int i, j;
|
|
|
|
/* Prepare folios for freeing */
|
|
for (i = 0, j = 0; i < folios->nr; i++) {
|
|
struct folio *folio = folios->folios[i];
|
|
unsigned long pfn = folio_pfn(folio);
|
|
unsigned int order = folio_order(folio);
|
|
|
|
if (!free_pages_prepare(&folio->page, order))
|
|
continue;
|
|
/*
|
|
* Free orders not handled on the PCP directly to the
|
|
* allocator.
|
|
*/
|
|
if (!pcp_allowed_order(order)) {
|
|
free_one_page(folio_zone(folio), &folio->page,
|
|
pfn, order, FPI_NONE);
|
|
continue;
|
|
}
|
|
folio->private = (void *)(unsigned long)order;
|
|
if (j != i)
|
|
folios->folios[j] = folio;
|
|
j++;
|
|
}
|
|
folios->nr = j;
|
|
|
|
for (i = 0; i < folios->nr; i++) {
|
|
struct folio *folio = folios->folios[i];
|
|
struct zone *zone = folio_zone(folio);
|
|
unsigned long pfn = folio_pfn(folio);
|
|
unsigned int order = (unsigned long)folio->private;
|
|
int migratetype;
|
|
|
|
folio->private = NULL;
|
|
migratetype = get_pfnblock_migratetype(&folio->page, pfn);
|
|
|
|
/* Different zone requires a different pcp lock */
|
|
if (zone != locked_zone ||
|
|
is_migrate_isolate(migratetype)) {
|
|
if (pcp) {
|
|
pcp_spin_unlock(pcp);
|
|
pcp_trylock_finish(UP_flags);
|
|
locked_zone = NULL;
|
|
pcp = NULL;
|
|
}
|
|
|
|
/*
|
|
* Free isolated pages directly to the
|
|
* allocator, see comment in free_frozen_pages.
|
|
*/
|
|
if (is_migrate_isolate(migratetype)) {
|
|
free_one_page(zone, &folio->page, pfn,
|
|
order, FPI_NONE);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* trylock is necessary as folios may be getting freed
|
|
* from IRQ or SoftIRQ context after an IO completion.
|
|
*/
|
|
pcp_trylock_prepare(UP_flags);
|
|
pcp = pcp_spin_trylock(zone->per_cpu_pageset);
|
|
if (unlikely(!pcp)) {
|
|
pcp_trylock_finish(UP_flags);
|
|
free_one_page(zone, &folio->page, pfn,
|
|
order, FPI_NONE);
|
|
continue;
|
|
}
|
|
locked_zone = zone;
|
|
}
|
|
|
|
/*
|
|
* Non-isolated types over MIGRATE_PCPTYPES get added
|
|
* to the MIGRATE_MOVABLE pcp list.
|
|
*/
|
|
if (unlikely(migratetype >= MIGRATE_PCPTYPES))
|
|
migratetype = MIGRATE_MOVABLE;
|
|
|
|
trace_mm_page_free_batched(&folio->page);
|
|
free_frozen_page_commit(zone, pcp, &folio->page, migratetype,
|
|
order);
|
|
}
|
|
|
|
if (pcp) {
|
|
pcp_spin_unlock(pcp);
|
|
pcp_trylock_finish(UP_flags);
|
|
}
|
|
folio_batch_reinit(folios);
|
|
}
|
|
|
|
/*
|
|
* split_page takes a non-compound higher-order page, and splits it into
|
|
* n (1<<order) sub-pages: page[0..n]
|
|
* Each sub-page must be freed individually.
|
|
*
|
|
* Note: this is probably too low level an operation for use in drivers.
|
|
* Please consult with lkml before using this in your driver.
|
|
*/
|
|
void split_page(struct page *page, unsigned int order)
|
|
{
|
|
int i;
|
|
|
|
VM_BUG_ON_PAGE(PageCompound(page), page);
|
|
VM_BUG_ON_PAGE(!page_count(page), page);
|
|
|
|
for (i = 1; i < (1 << order); i++)
|
|
set_page_refcounted(page + i);
|
|
split_page_owner(page, order, 0);
|
|
pgalloc_tag_split(page_folio(page), order, 0);
|
|
split_page_memcg(page, order, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(split_page);
|
|
|
|
int __isolate_free_page(struct page *page, unsigned int order)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
int mt = get_pageblock_migratetype(page);
|
|
|
|
if (!is_migrate_isolate(mt)) {
|
|
unsigned long watermark;
|
|
/*
|
|
* Obey watermarks as if the page was being allocated. We can
|
|
* emulate a high-order watermark check with a raised order-0
|
|
* watermark, because we already know our high-order page
|
|
* exists.
|
|
*/
|
|
watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
|
|
if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
|
|
return 0;
|
|
}
|
|
|
|
del_page_from_free_list(page, zone, order, mt);
|
|
|
|
/*
|
|
* Set the pageblock if the isolated page is at least half of a
|
|
* pageblock
|
|
*/
|
|
if (order >= pageblock_order - 1) {
|
|
struct page *endpage = page + (1 << order) - 1;
|
|
for (; page < endpage; page += pageblock_nr_pages) {
|
|
int mt = get_pageblock_migratetype(page);
|
|
/*
|
|
* Only change normal pageblocks (i.e., they can merge
|
|
* with others)
|
|
*/
|
|
if (migratetype_is_mergeable(mt))
|
|
move_freepages_block(zone, page, mt,
|
|
MIGRATE_MOVABLE);
|
|
}
|
|
}
|
|
|
|
return 1UL << order;
|
|
}
|
|
|
|
/**
|
|
* __putback_isolated_page - Return a now-isolated page back where we got it
|
|
* @page: Page that was isolated
|
|
* @order: Order of the isolated page
|
|
* @mt: The page's pageblock's migratetype
|
|
*
|
|
* This function is meant to return a page pulled from the free lists via
|
|
* __isolate_free_page back to the free lists they were pulled from.
|
|
*/
|
|
void __putback_isolated_page(struct page *page, unsigned int order, int mt)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
|
|
/* zone lock should be held when this function is called */
|
|
lockdep_assert_held(&zone->lock);
|
|
|
|
/* Return isolated page to tail of freelist. */
|
|
__free_one_page(page, page_to_pfn(page), zone, order, mt,
|
|
FPI_SKIP_REPORT_NOTIFY | FPI_TO_TAIL);
|
|
}
|
|
|
|
/*
|
|
* Update NUMA hit/miss statistics
|
|
*/
|
|
static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
|
|
long nr_account)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
enum numa_stat_item local_stat = NUMA_LOCAL;
|
|
|
|
/* skip numa counters update if numa stats is disabled */
|
|
if (!static_branch_likely(&vm_numa_stat_key))
|
|
return;
|
|
|
|
if (zone_to_nid(z) != numa_node_id())
|
|
local_stat = NUMA_OTHER;
|
|
|
|
if (zone_to_nid(z) == zone_to_nid(preferred_zone))
|
|
__count_numa_events(z, NUMA_HIT, nr_account);
|
|
else {
|
|
__count_numa_events(z, NUMA_MISS, nr_account);
|
|
__count_numa_events(preferred_zone, NUMA_FOREIGN, nr_account);
|
|
}
|
|
__count_numa_events(z, local_stat, nr_account);
|
|
#endif
|
|
}
|
|
|
|
static __always_inline
|
|
struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
|
|
unsigned int order, unsigned int alloc_flags,
|
|
int migratetype)
|
|
{
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
do {
|
|
page = NULL;
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
if (alloc_flags & ALLOC_HIGHATOMIC)
|
|
page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
|
|
if (!page) {
|
|
page = __rmqueue(zone, order, migratetype, alloc_flags);
|
|
|
|
/*
|
|
* If the allocation fails, allow OOM handling and
|
|
* order-0 (atomic) allocs access to HIGHATOMIC
|
|
* reserves as failing now is worse than failing a
|
|
* high-order atomic allocation in the future.
|
|
*/
|
|
if (!page && (alloc_flags & (ALLOC_OOM|ALLOC_NON_BLOCK)))
|
|
page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
|
|
|
|
if (!page) {
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
return NULL;
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
} while (check_new_pages(page, order));
|
|
|
|
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
|
|
zone_statistics(preferred_zone, zone, 1);
|
|
|
|
return page;
|
|
}
|
|
|
|
static int nr_pcp_alloc(struct per_cpu_pages *pcp, struct zone *zone, int order)
|
|
{
|
|
int high, base_batch, batch, max_nr_alloc;
|
|
int high_max, high_min;
|
|
|
|
base_batch = READ_ONCE(pcp->batch);
|
|
high_min = READ_ONCE(pcp->high_min);
|
|
high_max = READ_ONCE(pcp->high_max);
|
|
high = pcp->high = clamp(pcp->high, high_min, high_max);
|
|
|
|
/* Check for PCP disabled or boot pageset */
|
|
if (unlikely(high < base_batch))
|
|
return 1;
|
|
|
|
if (order)
|
|
batch = base_batch;
|
|
else
|
|
batch = (base_batch << pcp->alloc_factor);
|
|
|
|
/*
|
|
* If we had larger pcp->high, we could avoid to allocate from
|
|
* zone.
|
|
*/
|
|
if (high_min != high_max && !test_bit(ZONE_BELOW_HIGH, &zone->flags))
|
|
high = pcp->high = min(high + batch, high_max);
|
|
|
|
if (!order) {
|
|
max_nr_alloc = max(high - pcp->count - base_batch, base_batch);
|
|
/*
|
|
* Double the number of pages allocated each time there is
|
|
* subsequent allocation of order-0 pages without any freeing.
|
|
*/
|
|
if (batch <= max_nr_alloc &&
|
|
pcp->alloc_factor < CONFIG_PCP_BATCH_SCALE_MAX)
|
|
pcp->alloc_factor++;
|
|
batch = min(batch, max_nr_alloc);
|
|
}
|
|
|
|
/*
|
|
* Scale batch relative to order if batch implies free pages
|
|
* can be stored on the PCP. Batch can be 1 for small zones or
|
|
* for boot pagesets which should never store free pages as
|
|
* the pages may belong to arbitrary zones.
|
|
*/
|
|
if (batch > 1)
|
|
batch = max(batch >> order, 2);
|
|
|
|
return batch;
|
|
}
|
|
|
|
/* Remove page from the per-cpu list, caller must protect the list */
|
|
static inline
|
|
struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order,
|
|
int migratetype,
|
|
unsigned int alloc_flags,
|
|
struct per_cpu_pages *pcp,
|
|
struct list_head *list)
|
|
{
|
|
struct page *page;
|
|
|
|
do {
|
|
if (list_empty(list)) {
|
|
int batch = nr_pcp_alloc(pcp, zone, order);
|
|
int alloced;
|
|
|
|
alloced = rmqueue_bulk(zone, order,
|
|
batch, list,
|
|
migratetype, alloc_flags);
|
|
|
|
pcp->count += alloced << order;
|
|
if (unlikely(list_empty(list)))
|
|
return NULL;
|
|
}
|
|
|
|
page = list_first_entry(list, struct page, pcp_list);
|
|
list_del(&page->pcp_list);
|
|
pcp->count -= 1 << order;
|
|
} while (check_new_pages(page, order));
|
|
|
|
return page;
|
|
}
|
|
|
|
/* Lock and remove page from the per-cpu list */
|
|
static struct page *rmqueue_pcplist(struct zone *preferred_zone,
|
|
struct zone *zone, unsigned int order,
|
|
int migratetype, unsigned int alloc_flags)
|
|
{
|
|
struct per_cpu_pages *pcp;
|
|
struct list_head *list;
|
|
struct page *page;
|
|
unsigned long __maybe_unused UP_flags;
|
|
|
|
/* spin_trylock may fail due to a parallel drain or IRQ reentrancy. */
|
|
pcp_trylock_prepare(UP_flags);
|
|
pcp = pcp_spin_trylock(zone->per_cpu_pageset);
|
|
if (!pcp) {
|
|
pcp_trylock_finish(UP_flags);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* On allocation, reduce the number of pages that are batch freed.
|
|
* See nr_pcp_free() where free_factor is increased for subsequent
|
|
* frees.
|
|
*/
|
|
pcp->free_count >>= 1;
|
|
list = &pcp->lists[order_to_pindex(migratetype, order)];
|
|
page = __rmqueue_pcplist(zone, order, migratetype, alloc_flags, pcp, list);
|
|
pcp_spin_unlock(pcp);
|
|
pcp_trylock_finish(UP_flags);
|
|
if (page) {
|
|
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
|
|
zone_statistics(preferred_zone, zone, 1);
|
|
}
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Allocate a page from the given zone.
|
|
* Use pcplists for THP or "cheap" high-order allocations.
|
|
*/
|
|
|
|
/*
|
|
* Do not instrument rmqueue() with KMSAN. This function may call
|
|
* __msan_poison_alloca() through a call to set_pfnblock_flags_mask().
|
|
* If __msan_poison_alloca() attempts to allocate pages for the stack depot, it
|
|
* may call rmqueue() again, which will result in a deadlock.
|
|
*/
|
|
__no_sanitize_memory
|
|
static inline
|
|
struct page *rmqueue(struct zone *preferred_zone,
|
|
struct zone *zone, unsigned int order,
|
|
gfp_t gfp_flags, unsigned int alloc_flags,
|
|
int migratetype)
|
|
{
|
|
struct page *page;
|
|
|
|
if (likely(pcp_allowed_order(order))) {
|
|
page = rmqueue_pcplist(preferred_zone, zone, order,
|
|
migratetype, alloc_flags);
|
|
if (likely(page))
|
|
goto out;
|
|
}
|
|
|
|
page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags,
|
|
migratetype);
|
|
|
|
out:
|
|
/* Separate test+clear to avoid unnecessary atomics */
|
|
if ((alloc_flags & ALLOC_KSWAPD) &&
|
|
unlikely(test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags))) {
|
|
clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
|
|
wakeup_kswapd(zone, 0, 0, zone_idx(zone));
|
|
}
|
|
|
|
VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
|
|
return page;
|
|
}
|
|
|
|
static inline long __zone_watermark_unusable_free(struct zone *z,
|
|
unsigned int order, unsigned int alloc_flags)
|
|
{
|
|
long unusable_free = (1 << order) - 1;
|
|
|
|
/*
|
|
* If the caller does not have rights to reserves below the min
|
|
* watermark then subtract the free pages reserved for highatomic.
|
|
*/
|
|
if (likely(!(alloc_flags & ALLOC_RESERVES)))
|
|
unusable_free += READ_ONCE(z->nr_free_highatomic);
|
|
|
|
#ifdef CONFIG_CMA
|
|
/* If allocation can't use CMA areas don't use free CMA pages */
|
|
if (!(alloc_flags & ALLOC_CMA))
|
|
unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES);
|
|
#endif
|
|
|
|
return unusable_free;
|
|
}
|
|
|
|
/*
|
|
* Return true if free base pages are above 'mark'. For high-order checks it
|
|
* will return true of the order-0 watermark is reached and there is at least
|
|
* one free page of a suitable size. Checking now avoids taking the zone lock
|
|
* to check in the allocation paths if no pages are free.
|
|
*/
|
|
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
|
|
int highest_zoneidx, unsigned int alloc_flags,
|
|
long free_pages)
|
|
{
|
|
long min = mark;
|
|
int o;
|
|
|
|
/* free_pages may go negative - that's OK */
|
|
free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags);
|
|
|
|
if (unlikely(alloc_flags & ALLOC_RESERVES)) {
|
|
/*
|
|
* __GFP_HIGH allows access to 50% of the min reserve as well
|
|
* as OOM.
|
|
*/
|
|
if (alloc_flags & ALLOC_MIN_RESERVE) {
|
|
min -= min / 2;
|
|
|
|
/*
|
|
* Non-blocking allocations (e.g. GFP_ATOMIC) can
|
|
* access more reserves than just __GFP_HIGH. Other
|
|
* non-blocking allocations requests such as GFP_NOWAIT
|
|
* or (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) do not get
|
|
* access to the min reserve.
|
|
*/
|
|
if (alloc_flags & ALLOC_NON_BLOCK)
|
|
min -= min / 4;
|
|
}
|
|
|
|
/*
|
|
* OOM victims can try even harder than the normal reserve
|
|
* users on the grounds that it's definitely going to be in
|
|
* the exit path shortly and free memory. Any allocation it
|
|
* makes during the free path will be small and short-lived.
|
|
*/
|
|
if (alloc_flags & ALLOC_OOM)
|
|
min -= min / 2;
|
|
}
|
|
|
|
/*
|
|
* Check watermarks for an order-0 allocation request. If these
|
|
* are not met, then a high-order request also cannot go ahead
|
|
* even if a suitable page happened to be free.
|
|
*/
|
|
if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
|
|
return false;
|
|
|
|
/* If this is an order-0 request then the watermark is fine */
|
|
if (!order)
|
|
return true;
|
|
|
|
/* For a high-order request, check at least one suitable page is free */
|
|
for (o = order; o < NR_PAGE_ORDERS; o++) {
|
|
struct free_area *area = &z->free_area[o];
|
|
int mt;
|
|
|
|
if (!area->nr_free)
|
|
continue;
|
|
|
|
for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
|
|
if (!free_area_empty(area, mt))
|
|
return true;
|
|
}
|
|
|
|
#ifdef CONFIG_CMA
|
|
if ((alloc_flags & ALLOC_CMA) &&
|
|
!free_area_empty(area, MIGRATE_CMA)) {
|
|
return true;
|
|
}
|
|
#endif
|
|
if ((alloc_flags & (ALLOC_HIGHATOMIC|ALLOC_OOM)) &&
|
|
!free_area_empty(area, MIGRATE_HIGHATOMIC)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
|
|
int highest_zoneidx, unsigned int alloc_flags)
|
|
{
|
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
|
|
zone_page_state(z, NR_FREE_PAGES));
|
|
}
|
|
|
|
static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
|
|
unsigned long mark, int highest_zoneidx,
|
|
unsigned int alloc_flags, gfp_t gfp_mask)
|
|
{
|
|
long free_pages;
|
|
|
|
free_pages = zone_page_state(z, NR_FREE_PAGES);
|
|
|
|
/*
|
|
* Fast check for order-0 only. If this fails then the reserves
|
|
* need to be calculated.
|
|
*/
|
|
if (!order) {
|
|
long usable_free;
|
|
long reserved;
|
|
|
|
usable_free = free_pages;
|
|
reserved = __zone_watermark_unusable_free(z, 0, alloc_flags);
|
|
|
|
/* reserved may over estimate high-atomic reserves. */
|
|
usable_free -= min(usable_free, reserved);
|
|
if (usable_free > mark + z->lowmem_reserve[highest_zoneidx])
|
|
return true;
|
|
}
|
|
|
|
if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
|
|
free_pages))
|
|
return true;
|
|
|
|
/*
|
|
* Ignore watermark boosting for __GFP_HIGH order-0 allocations
|
|
* when checking the min watermark. The min watermark is the
|
|
* point where boosting is ignored so that kswapd is woken up
|
|
* when below the low watermark.
|
|
*/
|
|
if (unlikely(!order && (alloc_flags & ALLOC_MIN_RESERVE) && z->watermark_boost
|
|
&& ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) {
|
|
mark = z->_watermark[WMARK_MIN];
|
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx,
|
|
alloc_flags, free_pages);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
|
|
unsigned long mark, int highest_zoneidx)
|
|
{
|
|
long free_pages = zone_page_state(z, NR_FREE_PAGES);
|
|
|
|
if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
|
|
free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
|
|
|
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0,
|
|
free_pages);
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE;
|
|
|
|
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
|
|
{
|
|
return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
|
|
node_reclaim_distance;
|
|
}
|
|
#else /* CONFIG_NUMA */
|
|
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
|
|
{
|
|
return true;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
/*
|
|
* The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
|
|
* fragmentation is subtle. If the preferred zone was HIGHMEM then
|
|
* premature use of a lower zone may cause lowmem pressure problems that
|
|
* are worse than fragmentation. If the next zone is ZONE_DMA then it is
|
|
* probably too small. It only makes sense to spread allocations to avoid
|
|
* fragmentation between the Normal and DMA32 zones.
|
|
*/
|
|
static inline unsigned int
|
|
alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
|
|
{
|
|
unsigned int alloc_flags;
|
|
|
|
/*
|
|
* __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
|
|
* to save a branch.
|
|
*/
|
|
alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
|
|
|
|
#ifdef CONFIG_ZONE_DMA32
|
|
if (!zone)
|
|
return alloc_flags;
|
|
|
|
if (zone_idx(zone) != ZONE_NORMAL)
|
|
return alloc_flags;
|
|
|
|
/*
|
|
* If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
|
|
* the pointer is within zone->zone_pgdat->node_zones[]. Also assume
|
|
* on UMA that if Normal is populated then so is DMA32.
|
|
*/
|
|
BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
|
|
if (nr_online_nodes > 1 && !populated_zone(--zone))
|
|
return alloc_flags;
|
|
|
|
alloc_flags |= ALLOC_NOFRAGMENT;
|
|
#endif /* CONFIG_ZONE_DMA32 */
|
|
return alloc_flags;
|
|
}
|
|
|
|
/* Must be called after current_gfp_context() which can change gfp_mask */
|
|
static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask,
|
|
unsigned int alloc_flags)
|
|
{
|
|
#ifdef CONFIG_CMA
|
|
if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
|
|
alloc_flags |= ALLOC_CMA;
|
|
#endif
|
|
return alloc_flags;
|
|
}
|
|
|
|
/*
|
|
* get_page_from_freelist goes through the zonelist trying to allocate
|
|
* a page.
|
|
*/
|
|
static struct page *
|
|
get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
|
|
const struct alloc_context *ac)
|
|
{
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
struct pglist_data *last_pgdat = NULL;
|
|
bool last_pgdat_dirty_ok = false;
|
|
bool no_fallback;
|
|
|
|
retry:
|
|
/*
|
|
* Scan zonelist, looking for a zone with enough free.
|
|
* See also cpuset_node_allowed() comment in kernel/cgroup/cpuset.c.
|
|
*/
|
|
no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
|
|
z = ac->preferred_zoneref;
|
|
for_next_zone_zonelist_nodemask(zone, z, ac->highest_zoneidx,
|
|
ac->nodemask) {
|
|
struct page *page;
|
|
unsigned long mark;
|
|
|
|
if (cpusets_enabled() &&
|
|
(alloc_flags & ALLOC_CPUSET) &&
|
|
!__cpuset_zone_allowed(zone, gfp_mask))
|
|
continue;
|
|
/*
|
|
* When allocating a page cache page for writing, we
|
|
* want to get it from a node that is within its dirty
|
|
* limit, such that no single node holds more than its
|
|
* proportional share of globally allowed dirty pages.
|
|
* The dirty limits take into account the node's
|
|
* lowmem reserves and high watermark so that kswapd
|
|
* should be able to balance it without having to
|
|
* write pages from its LRU list.
|
|
*
|
|
* XXX: For now, allow allocations to potentially
|
|
* exceed the per-node dirty limit in the slowpath
|
|
* (spread_dirty_pages unset) before going into reclaim,
|
|
* which is important when on a NUMA setup the allowed
|
|
* nodes are together not big enough to reach the
|
|
* global limit. The proper fix for these situations
|
|
* will require awareness of nodes in the
|
|
* dirty-throttling and the flusher threads.
|
|
*/
|
|
if (ac->spread_dirty_pages) {
|
|
if (last_pgdat != zone->zone_pgdat) {
|
|
last_pgdat = zone->zone_pgdat;
|
|
last_pgdat_dirty_ok = node_dirty_ok(zone->zone_pgdat);
|
|
}
|
|
|
|
if (!last_pgdat_dirty_ok)
|
|
continue;
|
|
}
|
|
|
|
if (no_fallback && nr_online_nodes > 1 &&
|
|
zone != zonelist_zone(ac->preferred_zoneref)) {
|
|
int local_nid;
|
|
|
|
/*
|
|
* If moving to a remote node, retry but allow
|
|
* fragmenting fallbacks. Locality is more important
|
|
* than fragmentation avoidance.
|
|
*/
|
|
local_nid = zonelist_node_idx(ac->preferred_zoneref);
|
|
if (zone_to_nid(zone) != local_nid) {
|
|
alloc_flags &= ~ALLOC_NOFRAGMENT;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
cond_accept_memory(zone, order);
|
|
|
|
/*
|
|
* Detect whether the number of free pages is below high
|
|
* watermark. If so, we will decrease pcp->high and free
|
|
* PCP pages in free path to reduce the possibility of
|
|
* premature page reclaiming. Detection is done here to
|
|
* avoid to do that in hotter free path.
|
|
*/
|
|
if (test_bit(ZONE_BELOW_HIGH, &zone->flags))
|
|
goto check_alloc_wmark;
|
|
|
|
mark = high_wmark_pages(zone);
|
|
if (zone_watermark_fast(zone, order, mark,
|
|
ac->highest_zoneidx, alloc_flags,
|
|
gfp_mask))
|
|
goto try_this_zone;
|
|
else
|
|
set_bit(ZONE_BELOW_HIGH, &zone->flags);
|
|
|
|
check_alloc_wmark:
|
|
mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
|
|
if (!zone_watermark_fast(zone, order, mark,
|
|
ac->highest_zoneidx, alloc_flags,
|
|
gfp_mask)) {
|
|
int ret;
|
|
|
|
if (cond_accept_memory(zone, order))
|
|
goto try_this_zone;
|
|
|
|
/*
|
|
* Watermark failed for this zone, but see if we can
|
|
* grow this zone if it contains deferred pages.
|
|
*/
|
|
if (deferred_pages_enabled()) {
|
|
if (_deferred_grow_zone(zone, order))
|
|
goto try_this_zone;
|
|
}
|
|
/* Checked here to keep the fast path fast */
|
|
BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
|
|
if (alloc_flags & ALLOC_NO_WATERMARKS)
|
|
goto try_this_zone;
|
|
|
|
if (!node_reclaim_enabled() ||
|
|
!zone_allows_reclaim(zonelist_zone(ac->preferred_zoneref), zone))
|
|
continue;
|
|
|
|
ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
|
|
switch (ret) {
|
|
case NODE_RECLAIM_NOSCAN:
|
|
/* did not scan */
|
|
continue;
|
|
case NODE_RECLAIM_FULL:
|
|
/* scanned but unreclaimable */
|
|
continue;
|
|
default:
|
|
/* did we reclaim enough */
|
|
if (zone_watermark_ok(zone, order, mark,
|
|
ac->highest_zoneidx, alloc_flags))
|
|
goto try_this_zone;
|
|
|
|
continue;
|
|
}
|
|
}
|
|
|
|
try_this_zone:
|
|
page = rmqueue(zonelist_zone(ac->preferred_zoneref), zone, order,
|
|
gfp_mask, alloc_flags, ac->migratetype);
|
|
if (page) {
|
|
prep_new_page(page, order, gfp_mask, alloc_flags);
|
|
|
|
/*
|
|
* If this is a high-order atomic allocation then check
|
|
* if the pageblock should be reserved for the future
|
|
*/
|
|
if (unlikely(alloc_flags & ALLOC_HIGHATOMIC))
|
|
reserve_highatomic_pageblock(page, order, zone);
|
|
|
|
return page;
|
|
} else {
|
|
if (cond_accept_memory(zone, order))
|
|
goto try_this_zone;
|
|
|
|
/* Try again if zone has deferred pages */
|
|
if (deferred_pages_enabled()) {
|
|
if (_deferred_grow_zone(zone, order))
|
|
goto try_this_zone;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* It's possible on a UMA machine to get through all zones that are
|
|
* fragmented. If avoiding fragmentation, reset and try again.
|
|
*/
|
|
if (no_fallback) {
|
|
alloc_flags &= ~ALLOC_NOFRAGMENT;
|
|
goto retry;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
|
|
{
|
|
unsigned int filter = SHOW_MEM_FILTER_NODES;
|
|
|
|
/*
|
|
* This documents exceptions given to allocations in certain
|
|
* contexts that are allowed to allocate outside current's set
|
|
* of allowed nodes.
|
|
*/
|
|
if (!(gfp_mask & __GFP_NOMEMALLOC))
|
|
if (tsk_is_oom_victim(current) ||
|
|
(current->flags & (PF_MEMALLOC | PF_EXITING)))
|
|
filter &= ~SHOW_MEM_FILTER_NODES;
|
|
if (!in_task() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
|
|
filter &= ~SHOW_MEM_FILTER_NODES;
|
|
|
|
__show_mem(filter, nodemask, gfp_zone(gfp_mask));
|
|
}
|
|
|
|
void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
|
|
|
|
if ((gfp_mask & __GFP_NOWARN) ||
|
|
!__ratelimit(&nopage_rs) ||
|
|
((gfp_mask & __GFP_DMA) && !has_managed_dma()))
|
|
return;
|
|
|
|
va_start(args, fmt);
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
|
|
current->comm, &vaf, gfp_mask, &gfp_mask,
|
|
nodemask_pr_args(nodemask));
|
|
va_end(args);
|
|
|
|
cpuset_print_current_mems_allowed();
|
|
pr_cont("\n");
|
|
dump_stack();
|
|
warn_alloc_show_mem(gfp_mask, nodemask);
|
|
}
|
|
|
|
static inline struct page *
|
|
__alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
|
|
unsigned int alloc_flags,
|
|
const struct alloc_context *ac)
|
|
{
|
|
struct page *page;
|
|
|
|
page = get_page_from_freelist(gfp_mask, order,
|
|
alloc_flags|ALLOC_CPUSET, ac);
|
|
/*
|
|
* fallback to ignore cpuset restriction if our nodes
|
|
* are depleted
|
|
*/
|
|
if (!page)
|
|
page = get_page_from_freelist(gfp_mask, order,
|
|
alloc_flags, ac);
|
|
return page;
|
|
}
|
|
|
|
static inline struct page *
|
|
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
|
|
const struct alloc_context *ac, unsigned long *did_some_progress)
|
|
{
|
|
struct oom_control oc = {
|
|
.zonelist = ac->zonelist,
|
|
.nodemask = ac->nodemask,
|
|
.memcg = NULL,
|
|
.gfp_mask = gfp_mask,
|
|
.order = order,
|
|
};
|
|
struct page *page;
|
|
|
|
*did_some_progress = 0;
|
|
|
|
/*
|
|
* Acquire the oom lock. If that fails, somebody else is
|
|
* making progress for us.
|
|
*/
|
|
if (!mutex_trylock(&oom_lock)) {
|
|
*did_some_progress = 1;
|
|
schedule_timeout_uninterruptible(1);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Go through the zonelist yet one more time, keep very high watermark
|
|
* here, this is only to catch a parallel oom killing, we must fail if
|
|
* we're still under heavy pressure. But make sure that this reclaim
|
|
* attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
|
|
* allocation which will never fail due to oom_lock already held.
|
|
*/
|
|
page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
|
|
~__GFP_DIRECT_RECLAIM, order,
|
|
ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
|
|
if (page)
|
|
goto out;
|
|
|
|
/* Coredumps can quickly deplete all memory reserves */
|
|
if (current->flags & PF_DUMPCORE)
|
|
goto out;
|
|
/* The OOM killer will not help higher order allocs */
|
|
if (order > PAGE_ALLOC_COSTLY_ORDER)
|
|
goto out;
|
|
/*
|
|
* We have already exhausted all our reclaim opportunities without any
|
|
* success so it is time to admit defeat. We will skip the OOM killer
|
|
* because it is very likely that the caller has a more reasonable
|
|
* fallback than shooting a random task.
|
|
*
|
|
* The OOM killer may not free memory on a specific node.
|
|
*/
|
|
if (gfp_mask & (__GFP_RETRY_MAYFAIL | __GFP_THISNODE))
|
|
goto out;
|
|
/* The OOM killer does not needlessly kill tasks for lowmem */
|
|
if (ac->highest_zoneidx < ZONE_NORMAL)
|
|
goto out;
|
|
if (pm_suspended_storage())
|
|
goto out;
|
|
/*
|
|
* XXX: GFP_NOFS allocations should rather fail than rely on
|
|
* other request to make a forward progress.
|
|
* We are in an unfortunate situation where out_of_memory cannot
|
|
* do much for this context but let's try it to at least get
|
|
* access to memory reserved if the current task is killed (see
|
|
* out_of_memory). Once filesystems are ready to handle allocation
|
|
* failures more gracefully we should just bail out here.
|
|
*/
|
|
|
|
/* Exhausted what can be done so it's blame time */
|
|
if (out_of_memory(&oc) ||
|
|
WARN_ON_ONCE_GFP(gfp_mask & __GFP_NOFAIL, gfp_mask)) {
|
|
*did_some_progress = 1;
|
|
|
|
/*
|
|
* Help non-failing allocations by giving them access to memory
|
|
* reserves
|
|
*/
|
|
if (gfp_mask & __GFP_NOFAIL)
|
|
page = __alloc_pages_cpuset_fallback(gfp_mask, order,
|
|
ALLOC_NO_WATERMARKS, ac);
|
|
}
|
|
out:
|
|
mutex_unlock(&oom_lock);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Maximum number of compaction retries with a progress before OOM
|
|
* killer is consider as the only way to move forward.
|
|
*/
|
|
#define MAX_COMPACT_RETRIES 16
|
|
|
|
#ifdef CONFIG_COMPACTION
|
|
/* Try memory compaction for high-order allocations before reclaim */
|
|
static struct page *
|
|
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
|
|
unsigned int alloc_flags, const struct alloc_context *ac,
|
|
enum compact_priority prio, enum compact_result *compact_result)
|
|
{
|
|
struct page *page = NULL;
|
|
unsigned long pflags;
|
|
unsigned int noreclaim_flag;
|
|
|
|
if (!order)
|
|
return NULL;
|
|
|
|
psi_memstall_enter(&pflags);
|
|
delayacct_compact_start();
|
|
noreclaim_flag = memalloc_noreclaim_save();
|
|
|
|
*compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
|
|
prio, &page);
|
|
|
|
memalloc_noreclaim_restore(noreclaim_flag);
|
|
psi_memstall_leave(&pflags);
|
|
delayacct_compact_end();
|
|
|
|
if (*compact_result == COMPACT_SKIPPED)
|
|
return NULL;
|
|
/*
|
|
* At least in one zone compaction wasn't deferred or skipped, so let's
|
|
* count a compaction stall
|
|
*/
|
|
count_vm_event(COMPACTSTALL);
|
|
|
|
/* Prep a captured page if available */
|
|
if (page)
|
|
prep_new_page(page, order, gfp_mask, alloc_flags);
|
|
|
|
/* Try get a page from the freelist if available */
|
|
if (!page)
|
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
|
|
|
|
if (page) {
|
|
struct zone *zone = page_zone(page);
|
|
|
|
zone->compact_blockskip_flush = false;
|
|
compaction_defer_reset(zone, order, true);
|
|
count_vm_event(COMPACTSUCCESS);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* It's bad if compaction run occurs and fails. The most likely reason
|
|
* is that pages exist, but not enough to satisfy watermarks.
|
|
*/
|
|
count_vm_event(COMPACTFAIL);
|
|
|
|
cond_resched();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static inline bool
|
|
should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
|
|
enum compact_result compact_result,
|
|
enum compact_priority *compact_priority,
|
|
int *compaction_retries)
|
|
{
|
|
int max_retries = MAX_COMPACT_RETRIES;
|
|
int min_priority;
|
|
bool ret = false;
|
|
int retries = *compaction_retries;
|
|
enum compact_priority priority = *compact_priority;
|
|
|
|
if (!order)
|
|
return false;
|
|
|
|
if (fatal_signal_pending(current))
|
|
return false;
|
|
|
|
/*
|
|
* Compaction was skipped due to a lack of free order-0
|
|
* migration targets. Continue if reclaim can help.
|
|
*/
|
|
if (compact_result == COMPACT_SKIPPED) {
|
|
ret = compaction_zonelist_suitable(ac, order, alloc_flags);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Compaction managed to coalesce some page blocks, but the
|
|
* allocation failed presumably due to a race. Retry some.
|
|
*/
|
|
if (compact_result == COMPACT_SUCCESS) {
|
|
/*
|
|
* !costly requests are much more important than
|
|
* __GFP_RETRY_MAYFAIL costly ones because they are de
|
|
* facto nofail and invoke OOM killer to move on while
|
|
* costly can fail and users are ready to cope with
|
|
* that. 1/4 retries is rather arbitrary but we would
|
|
* need much more detailed feedback from compaction to
|
|
* make a better decision.
|
|
*/
|
|
if (order > PAGE_ALLOC_COSTLY_ORDER)
|
|
max_retries /= 4;
|
|
|
|
if (++(*compaction_retries) <= max_retries) {
|
|
ret = true;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Compaction failed. Retry with increasing priority.
|
|
*/
|
|
min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
|
|
MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
|
|
|
|
if (*compact_priority > min_priority) {
|
|
(*compact_priority)--;
|
|
*compaction_retries = 0;
|
|
ret = true;
|
|
}
|
|
out:
|
|
trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline struct page *
|
|
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
|
|
unsigned int alloc_flags, const struct alloc_context *ac,
|
|
enum compact_priority prio, enum compact_result *compact_result)
|
|
{
|
|
*compact_result = COMPACT_SKIPPED;
|
|
return NULL;
|
|
}
|
|
|
|
static inline bool
|
|
should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
|
|
enum compact_result compact_result,
|
|
enum compact_priority *compact_priority,
|
|
int *compaction_retries)
|
|
{
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
|
|
if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
|
|
return false;
|
|
|
|
/*
|
|
* There are setups with compaction disabled which would prefer to loop
|
|
* inside the allocator rather than hit the oom killer prematurely.
|
|
* Let's give them a good hope and keep retrying while the order-0
|
|
* watermarks are OK.
|
|
*/
|
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
|
|
ac->highest_zoneidx, ac->nodemask) {
|
|
if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
|
|
ac->highest_zoneidx, alloc_flags))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_COMPACTION */
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
static struct lockdep_map __fs_reclaim_map =
|
|
STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
|
|
|
|
static bool __need_reclaim(gfp_t gfp_mask)
|
|
{
|
|
/* no reclaim without waiting on it */
|
|
if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
|
|
return false;
|
|
|
|
/* this guy won't enter reclaim */
|
|
if (current->flags & PF_MEMALLOC)
|
|
return false;
|
|
|
|
if (gfp_mask & __GFP_NOLOCKDEP)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
void __fs_reclaim_acquire(unsigned long ip)
|
|
{
|
|
lock_acquire_exclusive(&__fs_reclaim_map, 0, 0, NULL, ip);
|
|
}
|
|
|
|
void __fs_reclaim_release(unsigned long ip)
|
|
{
|
|
lock_release(&__fs_reclaim_map, ip);
|
|
}
|
|
|
|
void fs_reclaim_acquire(gfp_t gfp_mask)
|
|
{
|
|
gfp_mask = current_gfp_context(gfp_mask);
|
|
|
|
if (__need_reclaim(gfp_mask)) {
|
|
if (gfp_mask & __GFP_FS)
|
|
__fs_reclaim_acquire(_RET_IP_);
|
|
|
|
#ifdef CONFIG_MMU_NOTIFIER
|
|
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
|
|
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
|
|
#endif
|
|
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
|
|
|
|
void fs_reclaim_release(gfp_t gfp_mask)
|
|
{
|
|
gfp_mask = current_gfp_context(gfp_mask);
|
|
|
|
if (__need_reclaim(gfp_mask)) {
|
|
if (gfp_mask & __GFP_FS)
|
|
__fs_reclaim_release(_RET_IP_);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fs_reclaim_release);
|
|
#endif
|
|
|
|
/*
|
|
* Zonelists may change due to hotplug during allocation. Detect when zonelists
|
|
* have been rebuilt so allocation retries. Reader side does not lock and
|
|
* retries the allocation if zonelist changes. Writer side is protected by the
|
|
* embedded spin_lock.
|
|
*/
|
|
static DEFINE_SEQLOCK(zonelist_update_seq);
|
|
|
|
static unsigned int zonelist_iter_begin(void)
|
|
{
|
|
if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
|
|
return read_seqbegin(&zonelist_update_seq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int check_retry_zonelist(unsigned int seq)
|
|
{
|
|
if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
|
|
return read_seqretry(&zonelist_update_seq, seq);
|
|
|
|
return seq;
|
|
}
|
|
|
|
/* Perform direct synchronous page reclaim */
|
|
static unsigned long
|
|
__perform_reclaim(gfp_t gfp_mask, unsigned int order,
|
|
const struct alloc_context *ac)
|
|
{
|
|
unsigned int noreclaim_flag;
|
|
unsigned long progress;
|
|
|
|
cond_resched();
|
|
|
|
/* We now go into synchronous reclaim */
|
|
cpuset_memory_pressure_bump();
|
|
fs_reclaim_acquire(gfp_mask);
|
|
noreclaim_flag = memalloc_noreclaim_save();
|
|
|
|
progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
|
|
ac->nodemask);
|
|
|
|
memalloc_noreclaim_restore(noreclaim_flag);
|
|
fs_reclaim_release(gfp_mask);
|
|
|
|
cond_resched();
|
|
|
|
return progress;
|
|
}
|
|
|
|
/* The really slow allocator path where we enter direct reclaim */
|
|
static inline struct page *
|
|
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
|
|
unsigned int alloc_flags, const struct alloc_context *ac,
|
|
unsigned long *did_some_progress)
|
|
{
|
|
struct page *page = NULL;
|
|
unsigned long pflags;
|
|
bool drained = false;
|
|
|
|
psi_memstall_enter(&pflags);
|
|
*did_some_progress = __perform_reclaim(gfp_mask, order, ac);
|
|
if (unlikely(!(*did_some_progress)))
|
|
goto out;
|
|
|
|
retry:
|
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
|
|
|
|
/*
|
|
* If an allocation failed after direct reclaim, it could be because
|
|
* pages are pinned on the per-cpu lists or in high alloc reserves.
|
|
* Shrink them and try again
|
|
*/
|
|
if (!page && !drained) {
|
|
unreserve_highatomic_pageblock(ac, false);
|
|
drain_all_pages(NULL);
|
|
drained = true;
|
|
goto retry;
|
|
}
|
|
out:
|
|
psi_memstall_leave(&pflags);
|
|
|
|
return page;
|
|
}
|
|
|
|
static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
|
|
const struct alloc_context *ac)
|
|
{
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
pg_data_t *last_pgdat = NULL;
|
|
enum zone_type highest_zoneidx = ac->highest_zoneidx;
|
|
|
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
|
|
ac->nodemask) {
|
|
if (!managed_zone(zone))
|
|
continue;
|
|
if (last_pgdat != zone->zone_pgdat) {
|
|
wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
|
|
last_pgdat = zone->zone_pgdat;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline unsigned int
|
|
gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order)
|
|
{
|
|
unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
|
|
|
|
/*
|
|
* __GFP_HIGH is assumed to be the same as ALLOC_MIN_RESERVE
|
|
* and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
|
|
* to save two branches.
|
|
*/
|
|
BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_MIN_RESERVE);
|
|
BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
|
|
|
|
/*
|
|
* The caller may dip into page reserves a bit more if the caller
|
|
* cannot run direct reclaim, or if the caller has realtime scheduling
|
|
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
|
|
* set both ALLOC_NON_BLOCK and ALLOC_MIN_RESERVE(__GFP_HIGH).
|
|
*/
|
|
alloc_flags |= (__force int)
|
|
(gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
|
|
|
|
if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) {
|
|
/*
|
|
* Not worth trying to allocate harder for __GFP_NOMEMALLOC even
|
|
* if it can't schedule.
|
|
*/
|
|
if (!(gfp_mask & __GFP_NOMEMALLOC)) {
|
|
alloc_flags |= ALLOC_NON_BLOCK;
|
|
|
|
if (order > 0)
|
|
alloc_flags |= ALLOC_HIGHATOMIC;
|
|
}
|
|
|
|
/*
|
|
* Ignore cpuset mems for non-blocking __GFP_HIGH (probably
|
|
* GFP_ATOMIC) rather than fail, see the comment for
|
|
* cpuset_node_allowed().
|
|
*/
|
|
if (alloc_flags & ALLOC_MIN_RESERVE)
|
|
alloc_flags &= ~ALLOC_CPUSET;
|
|
} else if (unlikely(rt_or_dl_task(current)) && in_task())
|
|
alloc_flags |= ALLOC_MIN_RESERVE;
|
|
|
|
alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
|
|
|
|
return alloc_flags;
|
|
}
|
|
|
|
static bool oom_reserves_allowed(struct task_struct *tsk)
|
|
{
|
|
if (!tsk_is_oom_victim(tsk))
|
|
return false;
|
|
|
|
/*
|
|
* !MMU doesn't have oom reaper so give access to memory reserves
|
|
* only to the thread with TIF_MEMDIE set
|
|
*/
|
|
if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Distinguish requests which really need access to full memory
|
|
* reserves from oom victims which can live with a portion of it
|
|
*/
|
|
static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
|
|
{
|
|
if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
|
|
return 0;
|
|
if (gfp_mask & __GFP_MEMALLOC)
|
|
return ALLOC_NO_WATERMARKS;
|
|
if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
|
|
return ALLOC_NO_WATERMARKS;
|
|
if (!in_interrupt()) {
|
|
if (current->flags & PF_MEMALLOC)
|
|
return ALLOC_NO_WATERMARKS;
|
|
else if (oom_reserves_allowed(current))
|
|
return ALLOC_OOM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
|
|
{
|
|
return !!__gfp_pfmemalloc_flags(gfp_mask);
|
|
}
|
|
|
|
/*
|
|
* Checks whether it makes sense to retry the reclaim to make a forward progress
|
|
* for the given allocation request.
|
|
*
|
|
* We give up when we either have tried MAX_RECLAIM_RETRIES in a row
|
|
* without success, or when we couldn't even meet the watermark if we
|
|
* reclaimed all remaining pages on the LRU lists.
|
|
*
|
|
* Returns true if a retry is viable or false to enter the oom path.
|
|
*/
|
|
static inline bool
|
|
should_reclaim_retry(gfp_t gfp_mask, unsigned order,
|
|
struct alloc_context *ac, int alloc_flags,
|
|
bool did_some_progress, int *no_progress_loops)
|
|
{
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
bool ret = false;
|
|
|
|
/*
|
|
* Costly allocations might have made a progress but this doesn't mean
|
|
* their order will become available due to high fragmentation so
|
|
* always increment the no progress counter for them
|
|
*/
|
|
if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
|
|
*no_progress_loops = 0;
|
|
else
|
|
(*no_progress_loops)++;
|
|
|
|
if (*no_progress_loops > MAX_RECLAIM_RETRIES)
|
|
goto out;
|
|
|
|
|
|
/*
|
|
* Keep reclaiming pages while there is a chance this will lead
|
|
* somewhere. If none of the target zones can satisfy our allocation
|
|
* request even if all reclaimable pages are considered then we are
|
|
* screwed and have to go OOM.
|
|
*/
|
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
|
|
ac->highest_zoneidx, ac->nodemask) {
|
|
unsigned long available;
|
|
unsigned long reclaimable;
|
|
unsigned long min_wmark = min_wmark_pages(zone);
|
|
bool wmark;
|
|
|
|
if (cpusets_enabled() &&
|
|
(alloc_flags & ALLOC_CPUSET) &&
|
|
!__cpuset_zone_allowed(zone, gfp_mask))
|
|
continue;
|
|
|
|
available = reclaimable = zone_reclaimable_pages(zone);
|
|
available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
|
|
|
|
/*
|
|
* Would the allocation succeed if we reclaimed all
|
|
* reclaimable pages?
|
|
*/
|
|
wmark = __zone_watermark_ok(zone, order, min_wmark,
|
|
ac->highest_zoneidx, alloc_flags, available);
|
|
trace_reclaim_retry_zone(z, order, reclaimable,
|
|
available, min_wmark, *no_progress_loops, wmark);
|
|
if (wmark) {
|
|
ret = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Memory allocation/reclaim might be called from a WQ context and the
|
|
* current implementation of the WQ concurrency control doesn't
|
|
* recognize that a particular WQ is congested if the worker thread is
|
|
* looping without ever sleeping. Therefore we have to do a short sleep
|
|
* here rather than calling cond_resched().
|
|
*/
|
|
if (current->flags & PF_WQ_WORKER)
|
|
schedule_timeout_uninterruptible(1);
|
|
else
|
|
cond_resched();
|
|
out:
|
|
/* Before OOM, exhaust highatomic_reserve */
|
|
if (!ret)
|
|
return unreserve_highatomic_pageblock(ac, true);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline bool
|
|
check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
|
|
{
|
|
/*
|
|
* It's possible that cpuset's mems_allowed and the nodemask from
|
|
* mempolicy don't intersect. This should be normally dealt with by
|
|
* policy_nodemask(), but it's possible to race with cpuset update in
|
|
* such a way the check therein was true, and then it became false
|
|
* before we got our cpuset_mems_cookie here.
|
|
* This assumes that for all allocations, ac->nodemask can come only
|
|
* from MPOL_BIND mempolicy (whose documented semantics is to be ignored
|
|
* when it does not intersect with the cpuset restrictions) or the
|
|
* caller can deal with a violated nodemask.
|
|
*/
|
|
if (cpusets_enabled() && ac->nodemask &&
|
|
!cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
|
|
ac->nodemask = NULL;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* When updating a task's mems_allowed or mempolicy nodemask, it is
|
|
* possible to race with parallel threads in such a way that our
|
|
* allocation can fail while the mask is being updated. If we are about
|
|
* to fail, check if the cpuset changed during allocation and if so,
|
|
* retry.
|
|
*/
|
|
if (read_mems_allowed_retry(cpuset_mems_cookie))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline struct page *
|
|
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
|
|
struct alloc_context *ac)
|
|
{
|
|
bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
|
|
bool can_compact = gfp_compaction_allowed(gfp_mask);
|
|
bool nofail = gfp_mask & __GFP_NOFAIL;
|
|
const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
|
|
struct page *page = NULL;
|
|
unsigned int alloc_flags;
|
|
unsigned long did_some_progress;
|
|
enum compact_priority compact_priority;
|
|
enum compact_result compact_result;
|
|
int compaction_retries;
|
|
int no_progress_loops;
|
|
unsigned int cpuset_mems_cookie;
|
|
unsigned int zonelist_iter_cookie;
|
|
int reserve_flags;
|
|
|
|
if (unlikely(nofail)) {
|
|
/*
|
|
* We most definitely don't want callers attempting to
|
|
* allocate greater than order-1 page units with __GFP_NOFAIL.
|
|
*/
|
|
WARN_ON_ONCE(order > 1);
|
|
/*
|
|
* Also we don't support __GFP_NOFAIL without __GFP_DIRECT_RECLAIM,
|
|
* otherwise, we may result in lockup.
|
|
*/
|
|
WARN_ON_ONCE(!can_direct_reclaim);
|
|
/*
|
|
* PF_MEMALLOC request from this context is rather bizarre
|
|
* because we cannot reclaim anything and only can loop waiting
|
|
* for somebody to do a work for us.
|
|
*/
|
|
WARN_ON_ONCE(current->flags & PF_MEMALLOC);
|
|
}
|
|
|
|
restart:
|
|
compaction_retries = 0;
|
|
no_progress_loops = 0;
|
|
compact_priority = DEF_COMPACT_PRIORITY;
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
zonelist_iter_cookie = zonelist_iter_begin();
|
|
|
|
/*
|
|
* The fast path uses conservative alloc_flags to succeed only until
|
|
* kswapd needs to be woken up, and to avoid the cost of setting up
|
|
* alloc_flags precisely. So we do that now.
|
|
*/
|
|
alloc_flags = gfp_to_alloc_flags(gfp_mask, order);
|
|
|
|
/*
|
|
* We need to recalculate the starting point for the zonelist iterator
|
|
* because we might have used different nodemask in the fast path, or
|
|
* there was a cpuset modification and we are retrying - otherwise we
|
|
* could end up iterating over non-eligible zones endlessly.
|
|
*/
|
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
|
|
ac->highest_zoneidx, ac->nodemask);
|
|
if (!zonelist_zone(ac->preferred_zoneref))
|
|
goto nopage;
|
|
|
|
/*
|
|
* Check for insane configurations where the cpuset doesn't contain
|
|
* any suitable zone to satisfy the request - e.g. non-movable
|
|
* GFP_HIGHUSER allocations from MOVABLE nodes only.
|
|
*/
|
|
if (cpusets_insane_config() && (gfp_mask & __GFP_HARDWALL)) {
|
|
struct zoneref *z = first_zones_zonelist(ac->zonelist,
|
|
ac->highest_zoneidx,
|
|
&cpuset_current_mems_allowed);
|
|
if (!zonelist_zone(z))
|
|
goto nopage;
|
|
}
|
|
|
|
if (alloc_flags & ALLOC_KSWAPD)
|
|
wake_all_kswapds(order, gfp_mask, ac);
|
|
|
|
/*
|
|
* The adjusted alloc_flags might result in immediate success, so try
|
|
* that first
|
|
*/
|
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/*
|
|
* For costly allocations, try direct compaction first, as it's likely
|
|
* that we have enough base pages and don't need to reclaim. For non-
|
|
* movable high-order allocations, do that as well, as compaction will
|
|
* try prevent permanent fragmentation by migrating from blocks of the
|
|
* same migratetype.
|
|
* Don't try this for allocations that are allowed to ignore
|
|
* watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
|
|
*/
|
|
if (can_direct_reclaim && can_compact &&
|
|
(costly_order ||
|
|
(order > 0 && ac->migratetype != MIGRATE_MOVABLE))
|
|
&& !gfp_pfmemalloc_allowed(gfp_mask)) {
|
|
page = __alloc_pages_direct_compact(gfp_mask, order,
|
|
alloc_flags, ac,
|
|
INIT_COMPACT_PRIORITY,
|
|
&compact_result);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/*
|
|
* Checks for costly allocations with __GFP_NORETRY, which
|
|
* includes some THP page fault allocations
|
|
*/
|
|
if (costly_order && (gfp_mask & __GFP_NORETRY)) {
|
|
/*
|
|
* If allocating entire pageblock(s) and compaction
|
|
* failed because all zones are below low watermarks
|
|
* or is prohibited because it recently failed at this
|
|
* order, fail immediately unless the allocator has
|
|
* requested compaction and reclaim retry.
|
|
*
|
|
* Reclaim is
|
|
* - potentially very expensive because zones are far
|
|
* below their low watermarks or this is part of very
|
|
* bursty high order allocations,
|
|
* - not guaranteed to help because isolate_freepages()
|
|
* may not iterate over freed pages as part of its
|
|
* linear scan, and
|
|
* - unlikely to make entire pageblocks free on its
|
|
* own.
|
|
*/
|
|
if (compact_result == COMPACT_SKIPPED ||
|
|
compact_result == COMPACT_DEFERRED)
|
|
goto nopage;
|
|
|
|
/*
|
|
* Looks like reclaim/compaction is worth trying, but
|
|
* sync compaction could be very expensive, so keep
|
|
* using async compaction.
|
|
*/
|
|
compact_priority = INIT_COMPACT_PRIORITY;
|
|
}
|
|
}
|
|
|
|
retry:
|
|
/* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
|
|
if (alloc_flags & ALLOC_KSWAPD)
|
|
wake_all_kswapds(order, gfp_mask, ac);
|
|
|
|
reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
|
|
if (reserve_flags)
|
|
alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags) |
|
|
(alloc_flags & ALLOC_KSWAPD);
|
|
|
|
/*
|
|
* Reset the nodemask and zonelist iterators if memory policies can be
|
|
* ignored. These allocations are high priority and system rather than
|
|
* user oriented.
|
|
*/
|
|
if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
|
|
ac->nodemask = NULL;
|
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
|
|
ac->highest_zoneidx, ac->nodemask);
|
|
}
|
|
|
|
/* Attempt with potentially adjusted zonelist and alloc_flags */
|
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/* Caller is not willing to reclaim, we can't balance anything */
|
|
if (!can_direct_reclaim)
|
|
goto nopage;
|
|
|
|
/* Avoid recursion of direct reclaim */
|
|
if (current->flags & PF_MEMALLOC)
|
|
goto nopage;
|
|
|
|
/* Try direct reclaim and then allocating */
|
|
page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
|
|
&did_some_progress);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/* Try direct compaction and then allocating */
|
|
page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
|
|
compact_priority, &compact_result);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/* Do not loop if specifically requested */
|
|
if (gfp_mask & __GFP_NORETRY)
|
|
goto nopage;
|
|
|
|
/*
|
|
* Do not retry costly high order allocations unless they are
|
|
* __GFP_RETRY_MAYFAIL and we can compact
|
|
*/
|
|
if (costly_order && (!can_compact ||
|
|
!(gfp_mask & __GFP_RETRY_MAYFAIL)))
|
|
goto nopage;
|
|
|
|
if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
|
|
did_some_progress > 0, &no_progress_loops))
|
|
goto retry;
|
|
|
|
/*
|
|
* It doesn't make any sense to retry for the compaction if the order-0
|
|
* reclaim is not able to make any progress because the current
|
|
* implementation of the compaction depends on the sufficient amount
|
|
* of free memory (see __compaction_suitable)
|
|
*/
|
|
if (did_some_progress > 0 && can_compact &&
|
|
should_compact_retry(ac, order, alloc_flags,
|
|
compact_result, &compact_priority,
|
|
&compaction_retries))
|
|
goto retry;
|
|
|
|
|
|
/*
|
|
* Deal with possible cpuset update races or zonelist updates to avoid
|
|
* a unnecessary OOM kill.
|
|
*/
|
|
if (check_retry_cpuset(cpuset_mems_cookie, ac) ||
|
|
check_retry_zonelist(zonelist_iter_cookie))
|
|
goto restart;
|
|
|
|
/* Reclaim has failed us, start killing things */
|
|
page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
/* Avoid allocations with no watermarks from looping endlessly */
|
|
if (tsk_is_oom_victim(current) &&
|
|
(alloc_flags & ALLOC_OOM ||
|
|
(gfp_mask & __GFP_NOMEMALLOC)))
|
|
goto nopage;
|
|
|
|
/* Retry as long as the OOM killer is making progress */
|
|
if (did_some_progress) {
|
|
no_progress_loops = 0;
|
|
goto retry;
|
|
}
|
|
|
|
nopage:
|
|
/*
|
|
* Deal with possible cpuset update races or zonelist updates to avoid
|
|
* a unnecessary OOM kill.
|
|
*/
|
|
if (check_retry_cpuset(cpuset_mems_cookie, ac) ||
|
|
check_retry_zonelist(zonelist_iter_cookie))
|
|
goto restart;
|
|
|
|
/*
|
|
* Make sure that __GFP_NOFAIL request doesn't leak out and make sure
|
|
* we always retry
|
|
*/
|
|
if (unlikely(nofail)) {
|
|
/*
|
|
* Lacking direct_reclaim we can't do anything to reclaim memory,
|
|
* we disregard these unreasonable nofail requests and still
|
|
* return NULL
|
|
*/
|
|
if (!can_direct_reclaim)
|
|
goto fail;
|
|
|
|
/*
|
|
* Help non-failing allocations by giving some access to memory
|
|
* reserves normally used for high priority non-blocking
|
|
* allocations but do not use ALLOC_NO_WATERMARKS because this
|
|
* could deplete whole memory reserves which would just make
|
|
* the situation worse.
|
|
*/
|
|
page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_MIN_RESERVE, ac);
|
|
if (page)
|
|
goto got_pg;
|
|
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
fail:
|
|
warn_alloc(gfp_mask, ac->nodemask,
|
|
"page allocation failure: order:%u", order);
|
|
got_pg:
|
|
return page;
|
|
}
|
|
|
|
static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
|
|
int preferred_nid, nodemask_t *nodemask,
|
|
struct alloc_context *ac, gfp_t *alloc_gfp,
|
|
unsigned int *alloc_flags)
|
|
{
|
|
ac->highest_zoneidx = gfp_zone(gfp_mask);
|
|
ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
|
|
ac->nodemask = nodemask;
|
|
ac->migratetype = gfp_migratetype(gfp_mask);
|
|
|
|
if (cpusets_enabled()) {
|
|
*alloc_gfp |= __GFP_HARDWALL;
|
|
/*
|
|
* When we are in the interrupt context, it is irrelevant
|
|
* to the current task context. It means that any node ok.
|
|
*/
|
|
if (in_task() && !ac->nodemask)
|
|
ac->nodemask = &cpuset_current_mems_allowed;
|
|
else
|
|
*alloc_flags |= ALLOC_CPUSET;
|
|
}
|
|
|
|
might_alloc(gfp_mask);
|
|
|
|
if (should_fail_alloc_page(gfp_mask, order))
|
|
return false;
|
|
|
|
*alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags);
|
|
|
|
/* Dirty zone balancing only done in the fast path */
|
|
ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
|
|
|
|
/*
|
|
* The preferred zone is used for statistics but crucially it is
|
|
* also used as the starting point for the zonelist iterator. It
|
|
* may get reset for allocations that ignore memory policies.
|
|
*/
|
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
|
|
ac->highest_zoneidx, ac->nodemask);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
|
|
* @gfp: GFP flags for the allocation
|
|
* @preferred_nid: The preferred NUMA node ID to allocate from
|
|
* @nodemask: Set of nodes to allocate from, may be NULL
|
|
* @nr_pages: The number of pages desired on the list or array
|
|
* @page_list: Optional list to store the allocated pages
|
|
* @page_array: Optional array to store the pages
|
|
*
|
|
* This is a batched version of the page allocator that attempts to
|
|
* allocate nr_pages quickly. Pages are added to page_list if page_list
|
|
* is not NULL, otherwise it is assumed that the page_array is valid.
|
|
*
|
|
* For lists, nr_pages is the number of pages that should be allocated.
|
|
*
|
|
* For arrays, only NULL elements are populated with pages and nr_pages
|
|
* is the maximum number of pages that will be stored in the array.
|
|
*
|
|
* Returns the number of pages on the list or array.
|
|
*/
|
|
unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid,
|
|
nodemask_t *nodemask, int nr_pages,
|
|
struct list_head *page_list,
|
|
struct page **page_array)
|
|
{
|
|
struct page *page;
|
|
unsigned long __maybe_unused UP_flags;
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
struct per_cpu_pages *pcp;
|
|
struct list_head *pcp_list;
|
|
struct alloc_context ac;
|
|
gfp_t alloc_gfp;
|
|
unsigned int alloc_flags = ALLOC_WMARK_LOW;
|
|
int nr_populated = 0, nr_account = 0;
|
|
|
|
/*
|
|
* Skip populated array elements to determine if any pages need
|
|
* to be allocated before disabling IRQs.
|
|
*/
|
|
while (page_array && nr_populated < nr_pages && page_array[nr_populated])
|
|
nr_populated++;
|
|
|
|
/* No pages requested? */
|
|
if (unlikely(nr_pages <= 0))
|
|
goto out;
|
|
|
|
/* Already populated array? */
|
|
if (unlikely(page_array && nr_pages - nr_populated == 0))
|
|
goto out;
|
|
|
|
/* Bulk allocator does not support memcg accounting. */
|
|
if (memcg_kmem_online() && (gfp & __GFP_ACCOUNT))
|
|
goto failed;
|
|
|
|
/* Use the single page allocator for one page. */
|
|
if (nr_pages - nr_populated == 1)
|
|
goto failed;
|
|
|
|
#ifdef CONFIG_PAGE_OWNER
|
|
/*
|
|
* PAGE_OWNER may recurse into the allocator to allocate space to
|
|
* save the stack with pagesets.lock held. Releasing/reacquiring
|
|
* removes much of the performance benefit of bulk allocation so
|
|
* force the caller to allocate one page at a time as it'll have
|
|
* similar performance to added complexity to the bulk allocator.
|
|
*/
|
|
if (static_branch_unlikely(&page_owner_inited))
|
|
goto failed;
|
|
#endif
|
|
|
|
/* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */
|
|
gfp &= gfp_allowed_mask;
|
|
alloc_gfp = gfp;
|
|
if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &alloc_gfp, &alloc_flags))
|
|
goto out;
|
|
gfp = alloc_gfp;
|
|
|
|
/* Find an allowed local zone that meets the low watermark. */
|
|
z = ac.preferred_zoneref;
|
|
for_next_zone_zonelist_nodemask(zone, z, ac.highest_zoneidx, ac.nodemask) {
|
|
unsigned long mark;
|
|
|
|
if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) &&
|
|
!__cpuset_zone_allowed(zone, gfp)) {
|
|
continue;
|
|
}
|
|
|
|
if (nr_online_nodes > 1 && zone != zonelist_zone(ac.preferred_zoneref) &&
|
|
zone_to_nid(zone) != zonelist_node_idx(ac.preferred_zoneref)) {
|
|
goto failed;
|
|
}
|
|
|
|
cond_accept_memory(zone, 0);
|
|
retry_this_zone:
|
|
mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK) + nr_pages;
|
|
if (zone_watermark_fast(zone, 0, mark,
|
|
zonelist_zone_idx(ac.preferred_zoneref),
|
|
alloc_flags, gfp)) {
|
|
break;
|
|
}
|
|
|
|
if (cond_accept_memory(zone, 0))
|
|
goto retry_this_zone;
|
|
|
|
/* Try again if zone has deferred pages */
|
|
if (deferred_pages_enabled()) {
|
|
if (_deferred_grow_zone(zone, 0))
|
|
goto retry_this_zone;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there are no allowed local zones that meets the watermarks then
|
|
* try to allocate a single page and reclaim if necessary.
|
|
*/
|
|
if (unlikely(!zone))
|
|
goto failed;
|
|
|
|
/* spin_trylock may fail due to a parallel drain or IRQ reentrancy. */
|
|
pcp_trylock_prepare(UP_flags);
|
|
pcp = pcp_spin_trylock(zone->per_cpu_pageset);
|
|
if (!pcp)
|
|
goto failed_irq;
|
|
|
|
/* Attempt the batch allocation */
|
|
pcp_list = &pcp->lists[order_to_pindex(ac.migratetype, 0)];
|
|
while (nr_populated < nr_pages) {
|
|
|
|
/* Skip existing pages */
|
|
if (page_array && page_array[nr_populated]) {
|
|
nr_populated++;
|
|
continue;
|
|
}
|
|
|
|
page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags,
|
|
pcp, pcp_list);
|
|
if (unlikely(!page)) {
|
|
/* Try and allocate at least one page */
|
|
if (!nr_account) {
|
|
pcp_spin_unlock(pcp);
|
|
goto failed_irq;
|
|
}
|
|
break;
|
|
}
|
|
nr_account++;
|
|
|
|
prep_new_page(page, 0, gfp, 0);
|
|
set_page_refcounted(page);
|
|
if (page_list)
|
|
list_add(&page->lru, page_list);
|
|
else
|
|
page_array[nr_populated] = page;
|
|
nr_populated++;
|
|
}
|
|
|
|
pcp_spin_unlock(pcp);
|
|
pcp_trylock_finish(UP_flags);
|
|
|
|
__count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account);
|
|
zone_statistics(zonelist_zone(ac.preferred_zoneref), zone, nr_account);
|
|
|
|
out:
|
|
return nr_populated;
|
|
|
|
failed_irq:
|
|
pcp_trylock_finish(UP_flags);
|
|
|
|
failed:
|
|
page = __alloc_pages_noprof(gfp, 0, preferred_nid, nodemask);
|
|
if (page) {
|
|
if (page_list)
|
|
list_add(&page->lru, page_list);
|
|
else
|
|
page_array[nr_populated] = page;
|
|
nr_populated++;
|
|
}
|
|
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL_GPL(alloc_pages_bulk_noprof);
|
|
|
|
/*
|
|
* This is the 'heart' of the zoned buddy allocator.
|
|
*/
|
|
struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
|
|
int preferred_nid, nodemask_t *nodemask)
|
|
{
|
|
struct page *page;
|
|
unsigned int alloc_flags = ALLOC_WMARK_LOW;
|
|
gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */
|
|
struct alloc_context ac = { };
|
|
|
|
/*
|
|
* There are several places where we assume that the order value is sane
|
|
* so bail out early if the request is out of bound.
|
|
*/
|
|
if (WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp))
|
|
return NULL;
|
|
|
|
gfp &= gfp_allowed_mask;
|
|
/*
|
|
* Apply scoped allocation constraints. This is mainly about GFP_NOFS
|
|
* resp. GFP_NOIO which has to be inherited for all allocation requests
|
|
* from a particular context which has been marked by
|
|
* memalloc_no{fs,io}_{save,restore}. And PF_MEMALLOC_PIN which ensures
|
|
* movable zones are not used during allocation.
|
|
*/
|
|
gfp = current_gfp_context(gfp);
|
|
alloc_gfp = gfp;
|
|
if (!prepare_alloc_pages(gfp, order, preferred_nid, nodemask, &ac,
|
|
&alloc_gfp, &alloc_flags))
|
|
return NULL;
|
|
|
|
/*
|
|
* Forbid the first pass from falling back to types that fragment
|
|
* memory until all local zones are considered.
|
|
*/
|
|
alloc_flags |= alloc_flags_nofragment(zonelist_zone(ac.preferred_zoneref), gfp);
|
|
|
|
/* First allocation attempt */
|
|
page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
|
|
if (likely(page))
|
|
goto out;
|
|
|
|
alloc_gfp = gfp;
|
|
ac.spread_dirty_pages = false;
|
|
|
|
/*
|
|
* Restore the original nodemask if it was potentially replaced with
|
|
* &cpuset_current_mems_allowed to optimize the fast-path attempt.
|
|
*/
|
|
ac.nodemask = nodemask;
|
|
|
|
page = __alloc_pages_slowpath(alloc_gfp, order, &ac);
|
|
|
|
out:
|
|
if (memcg_kmem_online() && (gfp & __GFP_ACCOUNT) && page &&
|
|
unlikely(__memcg_kmem_charge_page(page, gfp, order) != 0)) {
|
|
free_frozen_pages(page, order);
|
|
page = NULL;
|
|
}
|
|
|
|
trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype);
|
|
kmsan_alloc_page(page, order, alloc_gfp);
|
|
|
|
return page;
|
|
}
|
|
EXPORT_SYMBOL(__alloc_frozen_pages_noprof);
|
|
|
|
struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
|
|
int preferred_nid, nodemask_t *nodemask)
|
|
{
|
|
struct page *page;
|
|
|
|
page = __alloc_frozen_pages_noprof(gfp, order, preferred_nid, nodemask);
|
|
if (page)
|
|
set_page_refcounted(page);
|
|
return page;
|
|
}
|
|
EXPORT_SYMBOL(__alloc_pages_noprof);
|
|
|
|
struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
|
|
nodemask_t *nodemask)
|
|
{
|
|
struct page *page = __alloc_pages_noprof(gfp | __GFP_COMP, order,
|
|
preferred_nid, nodemask);
|
|
return page_rmappable_folio(page);
|
|
}
|
|
EXPORT_SYMBOL(__folio_alloc_noprof);
|
|
|
|
/*
|
|
* Common helper functions. Never use with __GFP_HIGHMEM because the returned
|
|
* address cannot represent highmem pages. Use alloc_pages and then kmap if
|
|
* you need to access high mem.
|
|
*/
|
|
unsigned long get_free_pages_noprof(gfp_t gfp_mask, unsigned int order)
|
|
{
|
|
struct page *page;
|
|
|
|
page = alloc_pages_noprof(gfp_mask & ~__GFP_HIGHMEM, order);
|
|
if (!page)
|
|
return 0;
|
|
return (unsigned long) page_address(page);
|
|
}
|
|
EXPORT_SYMBOL(get_free_pages_noprof);
|
|
|
|
unsigned long get_zeroed_page_noprof(gfp_t gfp_mask)
|
|
{
|
|
return get_free_pages_noprof(gfp_mask | __GFP_ZERO, 0);
|
|
}
|
|
EXPORT_SYMBOL(get_zeroed_page_noprof);
|
|
|
|
/**
|
|
* __free_pages - Free pages allocated with alloc_pages().
|
|
* @page: The page pointer returned from alloc_pages().
|
|
* @order: The order of the allocation.
|
|
*
|
|
* This function can free multi-page allocations that are not compound
|
|
* pages. It does not check that the @order passed in matches that of
|
|
* the allocation, so it is easy to leak memory. Freeing more memory
|
|
* than was allocated will probably emit a warning.
|
|
*
|
|
* If the last reference to this page is speculative, it will be released
|
|
* by put_page() which only frees the first page of a non-compound
|
|
* allocation. To prevent the remaining pages from being leaked, we free
|
|
* the subsequent pages here. If you want to use the page's reference
|
|
* count to decide when to free the allocation, you should allocate a
|
|
* compound page, and use put_page() instead of __free_pages().
|
|
*
|
|
* Context: May be called in interrupt context or while holding a normal
|
|
* spinlock, but not in NMI context or while holding a raw spinlock.
|
|
*/
|
|
void __free_pages(struct page *page, unsigned int order)
|
|
{
|
|
/* get PageHead before we drop reference */
|
|
int head = PageHead(page);
|
|
struct alloc_tag *tag = pgalloc_tag_get(page);
|
|
|
|
if (put_page_testzero(page))
|
|
free_frozen_pages(page, order);
|
|
else if (!head) {
|
|
pgalloc_tag_sub_pages(tag, (1 << order) - 1);
|
|
while (order-- > 0)
|
|
free_frozen_pages(page + (1 << order), order);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(__free_pages);
|
|
|
|
void free_pages(unsigned long addr, unsigned int order)
|
|
{
|
|
if (addr != 0) {
|
|
VM_BUG_ON(!virt_addr_valid((void *)addr));
|
|
__free_pages(virt_to_page((void *)addr), order);
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(free_pages);
|
|
|
|
static void *make_alloc_exact(unsigned long addr, unsigned int order,
|
|
size_t size)
|
|
{
|
|
if (addr) {
|
|
unsigned long nr = DIV_ROUND_UP(size, PAGE_SIZE);
|
|
struct page *page = virt_to_page((void *)addr);
|
|
struct page *last = page + nr;
|
|
|
|
split_page_owner(page, order, 0);
|
|
pgalloc_tag_split(page_folio(page), order, 0);
|
|
split_page_memcg(page, order, 0);
|
|
while (page < --last)
|
|
set_page_refcounted(last);
|
|
|
|
last = page + (1UL << order);
|
|
for (page += nr; page < last; page++)
|
|
__free_pages_ok(page, 0, FPI_TO_TAIL);
|
|
}
|
|
return (void *)addr;
|
|
}
|
|
|
|
/**
|
|
* alloc_pages_exact - allocate an exact number physically-contiguous pages.
|
|
* @size: the number of bytes to allocate
|
|
* @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
|
|
*
|
|
* This function is similar to alloc_pages(), except that it allocates the
|
|
* minimum number of pages to satisfy the request. alloc_pages() can only
|
|
* allocate memory in power-of-two pages.
|
|
*
|
|
* This function is also limited by MAX_PAGE_ORDER.
|
|
*
|
|
* Memory allocated by this function must be released by free_pages_exact().
|
|
*
|
|
* Return: pointer to the allocated area or %NULL in case of error.
|
|
*/
|
|
void *alloc_pages_exact_noprof(size_t size, gfp_t gfp_mask)
|
|
{
|
|
unsigned int order = get_order(size);
|
|
unsigned long addr;
|
|
|
|
if (WARN_ON_ONCE(gfp_mask & (__GFP_COMP | __GFP_HIGHMEM)))
|
|
gfp_mask &= ~(__GFP_COMP | __GFP_HIGHMEM);
|
|
|
|
addr = get_free_pages_noprof(gfp_mask, order);
|
|
return make_alloc_exact(addr, order, size);
|
|
}
|
|
EXPORT_SYMBOL(alloc_pages_exact_noprof);
|
|
|
|
/**
|
|
* alloc_pages_exact_nid - allocate an exact number of physically-contiguous
|
|
* pages on a node.
|
|
* @nid: the preferred node ID where memory should be allocated
|
|
* @size: the number of bytes to allocate
|
|
* @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
|
|
*
|
|
* Like alloc_pages_exact(), but try to allocate on node nid first before falling
|
|
* back.
|
|
*
|
|
* Return: pointer to the allocated area or %NULL in case of error.
|
|
*/
|
|
void * __meminit alloc_pages_exact_nid_noprof(int nid, size_t size, gfp_t gfp_mask)
|
|
{
|
|
unsigned int order = get_order(size);
|
|
struct page *p;
|
|
|
|
if (WARN_ON_ONCE(gfp_mask & (__GFP_COMP | __GFP_HIGHMEM)))
|
|
gfp_mask &= ~(__GFP_COMP | __GFP_HIGHMEM);
|
|
|
|
p = alloc_pages_node_noprof(nid, gfp_mask, order);
|
|
if (!p)
|
|
return NULL;
|
|
return make_alloc_exact((unsigned long)page_address(p), order, size);
|
|
}
|
|
|
|
/**
|
|
* free_pages_exact - release memory allocated via alloc_pages_exact()
|
|
* @virt: the value returned by alloc_pages_exact.
|
|
* @size: size of allocation, same value as passed to alloc_pages_exact().
|
|
*
|
|
* Release the memory allocated by a previous call to alloc_pages_exact.
|
|
*/
|
|
void free_pages_exact(void *virt, size_t size)
|
|
{
|
|
unsigned long addr = (unsigned long)virt;
|
|
unsigned long end = addr + PAGE_ALIGN(size);
|
|
|
|
while (addr < end) {
|
|
free_page(addr);
|
|
addr += PAGE_SIZE;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(free_pages_exact);
|
|
|
|
/**
|
|
* nr_free_zone_pages - count number of pages beyond high watermark
|
|
* @offset: The zone index of the highest zone
|
|
*
|
|
* nr_free_zone_pages() counts the number of pages which are beyond the
|
|
* high watermark within all zones at or below a given zone index. For each
|
|
* zone, the number of pages is calculated as:
|
|
*
|
|
* nr_free_zone_pages = managed_pages - high_pages
|
|
*
|
|
* Return: number of pages beyond high watermark.
|
|
*/
|
|
static unsigned long nr_free_zone_pages(int offset)
|
|
{
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
|
|
/* Just pick one node, since fallback list is circular */
|
|
unsigned long sum = 0;
|
|
|
|
struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
|
|
|
|
for_each_zone_zonelist(zone, z, zonelist, offset) {
|
|
unsigned long size = zone_managed_pages(zone);
|
|
unsigned long high = high_wmark_pages(zone);
|
|
if (size > high)
|
|
sum += size - high;
|
|
}
|
|
|
|
return sum;
|
|
}
|
|
|
|
/**
|
|
* nr_free_buffer_pages - count number of pages beyond high watermark
|
|
*
|
|
* nr_free_buffer_pages() counts the number of pages which are beyond the high
|
|
* watermark within ZONE_DMA and ZONE_NORMAL.
|
|
*
|
|
* Return: number of pages beyond high watermark within ZONE_DMA and
|
|
* ZONE_NORMAL.
|
|
*/
|
|
unsigned long nr_free_buffer_pages(void)
|
|
{
|
|
return nr_free_zone_pages(gfp_zone(GFP_USER));
|
|
}
|
|
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
|
|
|
|
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
|
|
{
|
|
zoneref->zone = zone;
|
|
zoneref->zone_idx = zone_idx(zone);
|
|
}
|
|
|
|
/*
|
|
* Builds allocation fallback zone lists.
|
|
*
|
|
* Add all populated zones of a node to the zonelist.
|
|
*/
|
|
static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
|
|
{
|
|
struct zone *zone;
|
|
enum zone_type zone_type = MAX_NR_ZONES;
|
|
int nr_zones = 0;
|
|
|
|
do {
|
|
zone_type--;
|
|
zone = pgdat->node_zones + zone_type;
|
|
if (populated_zone(zone)) {
|
|
zoneref_set_zone(zone, &zonerefs[nr_zones++]);
|
|
check_highest_zone(zone_type);
|
|
}
|
|
} while (zone_type);
|
|
|
|
return nr_zones;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
|
|
static int __parse_numa_zonelist_order(char *s)
|
|
{
|
|
/*
|
|
* We used to support different zonelists modes but they turned
|
|
* out to be just not useful. Let's keep the warning in place
|
|
* if somebody still use the cmd line parameter so that we do
|
|
* not fail it silently
|
|
*/
|
|
if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
|
|
pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static char numa_zonelist_order[] = "Node";
|
|
#define NUMA_ZONELIST_ORDER_LEN 16
|
|
/*
|
|
* sysctl handler for numa_zonelist_order
|
|
*/
|
|
static int numa_zonelist_order_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
if (write)
|
|
return __parse_numa_zonelist_order(buffer);
|
|
return proc_dostring(table, write, buffer, length, ppos);
|
|
}
|
|
|
|
static int node_load[MAX_NUMNODES];
|
|
|
|
/**
|
|
* find_next_best_node - find the next node that should appear in a given node's fallback list
|
|
* @node: node whose fallback list we're appending
|
|
* @used_node_mask: nodemask_t of already used nodes
|
|
*
|
|
* We use a number of factors to determine which is the next node that should
|
|
* appear on a given node's fallback list. The node should not have appeared
|
|
* already in @node's fallback list, and it should be the next closest node
|
|
* according to the distance array (which contains arbitrary distance values
|
|
* from each node to each node in the system), and should also prefer nodes
|
|
* with no CPUs, since presumably they'll have very little allocation pressure
|
|
* on them otherwise.
|
|
*
|
|
* Return: node id of the found node or %NUMA_NO_NODE if no node is found.
|
|
*/
|
|
int find_next_best_node(int node, nodemask_t *used_node_mask)
|
|
{
|
|
int n, val;
|
|
int min_val = INT_MAX;
|
|
int best_node = NUMA_NO_NODE;
|
|
|
|
/*
|
|
* Use the local node if we haven't already, but for memoryless local
|
|
* node, we should skip it and fall back to other nodes.
|
|
*/
|
|
if (!node_isset(node, *used_node_mask) && node_state(node, N_MEMORY)) {
|
|
node_set(node, *used_node_mask);
|
|
return node;
|
|
}
|
|
|
|
for_each_node_state(n, N_MEMORY) {
|
|
|
|
/* Don't want a node to appear more than once */
|
|
if (node_isset(n, *used_node_mask))
|
|
continue;
|
|
|
|
/* Use the distance array to find the distance */
|
|
val = node_distance(node, n);
|
|
|
|
/* Penalize nodes under us ("prefer the next node") */
|
|
val += (n < node);
|
|
|
|
/* Give preference to headless and unused nodes */
|
|
if (!cpumask_empty(cpumask_of_node(n)))
|
|
val += PENALTY_FOR_NODE_WITH_CPUS;
|
|
|
|
/* Slight preference for less loaded node */
|
|
val *= MAX_NUMNODES;
|
|
val += node_load[n];
|
|
|
|
if (val < min_val) {
|
|
min_val = val;
|
|
best_node = n;
|
|
}
|
|
}
|
|
|
|
if (best_node >= 0)
|
|
node_set(best_node, *used_node_mask);
|
|
|
|
return best_node;
|
|
}
|
|
|
|
|
|
/*
|
|
* Build zonelists ordered by node and zones within node.
|
|
* This results in maximum locality--normal zone overflows into local
|
|
* DMA zone, if any--but risks exhausting DMA zone.
|
|
*/
|
|
static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
|
|
unsigned nr_nodes)
|
|
{
|
|
struct zoneref *zonerefs;
|
|
int i;
|
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
|
|
|
|
for (i = 0; i < nr_nodes; i++) {
|
|
int nr_zones;
|
|
|
|
pg_data_t *node = NODE_DATA(node_order[i]);
|
|
|
|
nr_zones = build_zonerefs_node(node, zonerefs);
|
|
zonerefs += nr_zones;
|
|
}
|
|
zonerefs->zone = NULL;
|
|
zonerefs->zone_idx = 0;
|
|
}
|
|
|
|
/*
|
|
* Build __GFP_THISNODE zonelists
|
|
*/
|
|
static void build_thisnode_zonelists(pg_data_t *pgdat)
|
|
{
|
|
struct zoneref *zonerefs;
|
|
int nr_zones;
|
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
|
|
nr_zones = build_zonerefs_node(pgdat, zonerefs);
|
|
zonerefs += nr_zones;
|
|
zonerefs->zone = NULL;
|
|
zonerefs->zone_idx = 0;
|
|
}
|
|
|
|
/*
|
|
* Build zonelists ordered by zone and nodes within zones.
|
|
* This results in conserving DMA zone[s] until all Normal memory is
|
|
* exhausted, but results in overflowing to remote node while memory
|
|
* may still exist in local DMA zone.
|
|
*/
|
|
|
|
static void build_zonelists(pg_data_t *pgdat)
|
|
{
|
|
static int node_order[MAX_NUMNODES];
|
|
int node, nr_nodes = 0;
|
|
nodemask_t used_mask = NODE_MASK_NONE;
|
|
int local_node, prev_node;
|
|
|
|
/* NUMA-aware ordering of nodes */
|
|
local_node = pgdat->node_id;
|
|
prev_node = local_node;
|
|
|
|
memset(node_order, 0, sizeof(node_order));
|
|
while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
|
|
/*
|
|
* We don't want to pressure a particular node.
|
|
* So adding penalty to the first node in same
|
|
* distance group to make it round-robin.
|
|
*/
|
|
if (node_distance(local_node, node) !=
|
|
node_distance(local_node, prev_node))
|
|
node_load[node] += 1;
|
|
|
|
node_order[nr_nodes++] = node;
|
|
prev_node = node;
|
|
}
|
|
|
|
build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
|
|
build_thisnode_zonelists(pgdat);
|
|
pr_info("Fallback order for Node %d: ", local_node);
|
|
for (node = 0; node < nr_nodes; node++)
|
|
pr_cont("%d ", node_order[node]);
|
|
pr_cont("\n");
|
|
}
|
|
|
|
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
|
|
/*
|
|
* Return node id of node used for "local" allocations.
|
|
* I.e., first node id of first zone in arg node's generic zonelist.
|
|
* Used for initializing percpu 'numa_mem', which is used primarily
|
|
* for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
|
|
*/
|
|
int local_memory_node(int node)
|
|
{
|
|
struct zoneref *z;
|
|
|
|
z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
|
|
gfp_zone(GFP_KERNEL),
|
|
NULL);
|
|
return zonelist_node_idx(z);
|
|
}
|
|
#endif
|
|
|
|
static void setup_min_unmapped_ratio(void);
|
|
static void setup_min_slab_ratio(void);
|
|
#else /* CONFIG_NUMA */
|
|
|
|
static void build_zonelists(pg_data_t *pgdat)
|
|
{
|
|
struct zoneref *zonerefs;
|
|
int nr_zones;
|
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
|
|
nr_zones = build_zonerefs_node(pgdat, zonerefs);
|
|
zonerefs += nr_zones;
|
|
|
|
zonerefs->zone = NULL;
|
|
zonerefs->zone_idx = 0;
|
|
}
|
|
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
/*
|
|
* Boot pageset table. One per cpu which is going to be used for all
|
|
* zones and all nodes. The parameters will be set in such a way
|
|
* that an item put on a list will immediately be handed over to
|
|
* the buddy list. This is safe since pageset manipulation is done
|
|
* with interrupts disabled.
|
|
*
|
|
* The boot_pagesets must be kept even after bootup is complete for
|
|
* unused processors and/or zones. They do play a role for bootstrapping
|
|
* hotplugged processors.
|
|
*
|
|
* zoneinfo_show() and maybe other functions do
|
|
* not check if the processor is online before following the pageset pointer.
|
|
* Other parts of the kernel may not check if the zone is available.
|
|
*/
|
|
static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats);
|
|
/* These effectively disable the pcplists in the boot pageset completely */
|
|
#define BOOT_PAGESET_HIGH 0
|
|
#define BOOT_PAGESET_BATCH 1
|
|
static DEFINE_PER_CPU(struct per_cpu_pages, boot_pageset);
|
|
static DEFINE_PER_CPU(struct per_cpu_zonestat, boot_zonestats);
|
|
|
|
static void __build_all_zonelists(void *data)
|
|
{
|
|
int nid;
|
|
int __maybe_unused cpu;
|
|
pg_data_t *self = data;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* The zonelist_update_seq must be acquired with irqsave because the
|
|
* reader can be invoked from IRQ with GFP_ATOMIC.
|
|
*/
|
|
write_seqlock_irqsave(&zonelist_update_seq, flags);
|
|
/*
|
|
* Also disable synchronous printk() to prevent any printk() from
|
|
* trying to hold port->lock, for
|
|
* tty_insert_flip_string_and_push_buffer() on other CPU might be
|
|
* calling kmalloc(GFP_ATOMIC | __GFP_NOWARN) with port->lock held.
|
|
*/
|
|
printk_deferred_enter();
|
|
|
|
#ifdef CONFIG_NUMA
|
|
memset(node_load, 0, sizeof(node_load));
|
|
#endif
|
|
|
|
/*
|
|
* This node is hotadded and no memory is yet present. So just
|
|
* building zonelists is fine - no need to touch other nodes.
|
|
*/
|
|
if (self && !node_online(self->node_id)) {
|
|
build_zonelists(self);
|
|
} else {
|
|
/*
|
|
* All possible nodes have pgdat preallocated
|
|
* in free_area_init
|
|
*/
|
|
for_each_node(nid) {
|
|
pg_data_t *pgdat = NODE_DATA(nid);
|
|
|
|
build_zonelists(pgdat);
|
|
}
|
|
|
|
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
|
|
/*
|
|
* We now know the "local memory node" for each node--
|
|
* i.e., the node of the first zone in the generic zonelist.
|
|
* Set up numa_mem percpu variable for on-line cpus. During
|
|
* boot, only the boot cpu should be on-line; we'll init the
|
|
* secondary cpus' numa_mem as they come on-line. During
|
|
* node/memory hotplug, we'll fixup all on-line cpus.
|
|
*/
|
|
for_each_online_cpu(cpu)
|
|
set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
|
|
#endif
|
|
}
|
|
|
|
printk_deferred_exit();
|
|
write_sequnlock_irqrestore(&zonelist_update_seq, flags);
|
|
}
|
|
|
|
static noinline void __init
|
|
build_all_zonelists_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
__build_all_zonelists(NULL);
|
|
|
|
/*
|
|
* Initialize the boot_pagesets that are going to be used
|
|
* for bootstrapping processors. The real pagesets for
|
|
* each zone will be allocated later when the per cpu
|
|
* allocator is available.
|
|
*
|
|
* boot_pagesets are used also for bootstrapping offline
|
|
* cpus if the system is already booted because the pagesets
|
|
* are needed to initialize allocators on a specific cpu too.
|
|
* F.e. the percpu allocator needs the page allocator which
|
|
* needs the percpu allocator in order to allocate its pagesets
|
|
* (a chicken-egg dilemma).
|
|
*/
|
|
for_each_possible_cpu(cpu)
|
|
per_cpu_pages_init(&per_cpu(boot_pageset, cpu), &per_cpu(boot_zonestats, cpu));
|
|
|
|
mminit_verify_zonelist();
|
|
cpuset_init_current_mems_allowed();
|
|
}
|
|
|
|
/*
|
|
* unless system_state == SYSTEM_BOOTING.
|
|
*
|
|
* __ref due to call of __init annotated helper build_all_zonelists_init
|
|
* [protected by SYSTEM_BOOTING].
|
|
*/
|
|
void __ref build_all_zonelists(pg_data_t *pgdat)
|
|
{
|
|
unsigned long vm_total_pages;
|
|
|
|
if (system_state == SYSTEM_BOOTING) {
|
|
build_all_zonelists_init();
|
|
} else {
|
|
__build_all_zonelists(pgdat);
|
|
/* cpuset refresh routine should be here */
|
|
}
|
|
/* Get the number of free pages beyond high watermark in all zones. */
|
|
vm_total_pages = nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
|
|
/*
|
|
* Disable grouping by mobility if the number of pages in the
|
|
* system is too low to allow the mechanism to work. It would be
|
|
* more accurate, but expensive to check per-zone. This check is
|
|
* made on memory-hotadd so a system can start with mobility
|
|
* disabled and enable it later
|
|
*/
|
|
if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
|
|
page_group_by_mobility_disabled = 1;
|
|
else
|
|
page_group_by_mobility_disabled = 0;
|
|
|
|
pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
|
|
nr_online_nodes,
|
|
str_off_on(page_group_by_mobility_disabled),
|
|
vm_total_pages);
|
|
#ifdef CONFIG_NUMA
|
|
pr_info("Policy zone: %s\n", zone_names[policy_zone]);
|
|
#endif
|
|
}
|
|
|
|
static int zone_batchsize(struct zone *zone)
|
|
{
|
|
#ifdef CONFIG_MMU
|
|
int batch;
|
|
|
|
/*
|
|
* The number of pages to batch allocate is either ~0.1%
|
|
* of the zone or 1MB, whichever is smaller. The batch
|
|
* size is striking a balance between allocation latency
|
|
* and zone lock contention.
|
|
*/
|
|
batch = min(zone_managed_pages(zone) >> 10, SZ_1M / PAGE_SIZE);
|
|
batch /= 4; /* We effectively *= 4 below */
|
|
if (batch < 1)
|
|
batch = 1;
|
|
|
|
/*
|
|
* Clamp the batch to a 2^n - 1 value. Having a power
|
|
* of 2 value was found to be more likely to have
|
|
* suboptimal cache aliasing properties in some cases.
|
|
*
|
|
* For example if 2 tasks are alternately allocating
|
|
* batches of pages, one task can end up with a lot
|
|
* of pages of one half of the possible page colors
|
|
* and the other with pages of the other colors.
|
|
*/
|
|
batch = rounddown_pow_of_two(batch + batch/2) - 1;
|
|
|
|
return batch;
|
|
|
|
#else
|
|
/* The deferral and batching of frees should be suppressed under NOMMU
|
|
* conditions.
|
|
*
|
|
* The problem is that NOMMU needs to be able to allocate large chunks
|
|
* of contiguous memory as there's no hardware page translation to
|
|
* assemble apparent contiguous memory from discontiguous pages.
|
|
*
|
|
* Queueing large contiguous runs of pages for batching, however,
|
|
* causes the pages to actually be freed in smaller chunks. As there
|
|
* can be a significant delay between the individual batches being
|
|
* recycled, this leads to the once large chunks of space being
|
|
* fragmented and becoming unavailable for high-order allocations.
|
|
*/
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static int percpu_pagelist_high_fraction;
|
|
static int zone_highsize(struct zone *zone, int batch, int cpu_online,
|
|
int high_fraction)
|
|
{
|
|
#ifdef CONFIG_MMU
|
|
int high;
|
|
int nr_split_cpus;
|
|
unsigned long total_pages;
|
|
|
|
if (!high_fraction) {
|
|
/*
|
|
* By default, the high value of the pcp is based on the zone
|
|
* low watermark so that if they are full then background
|
|
* reclaim will not be started prematurely.
|
|
*/
|
|
total_pages = low_wmark_pages(zone);
|
|
} else {
|
|
/*
|
|
* If percpu_pagelist_high_fraction is configured, the high
|
|
* value is based on a fraction of the managed pages in the
|
|
* zone.
|
|
*/
|
|
total_pages = zone_managed_pages(zone) / high_fraction;
|
|
}
|
|
|
|
/*
|
|
* Split the high value across all online CPUs local to the zone. Note
|
|
* that early in boot that CPUs may not be online yet and that during
|
|
* CPU hotplug that the cpumask is not yet updated when a CPU is being
|
|
* onlined. For memory nodes that have no CPUs, split the high value
|
|
* across all online CPUs to mitigate the risk that reclaim is triggered
|
|
* prematurely due to pages stored on pcp lists.
|
|
*/
|
|
nr_split_cpus = cpumask_weight(cpumask_of_node(zone_to_nid(zone))) + cpu_online;
|
|
if (!nr_split_cpus)
|
|
nr_split_cpus = num_online_cpus();
|
|
high = total_pages / nr_split_cpus;
|
|
|
|
/*
|
|
* Ensure high is at least batch*4. The multiple is based on the
|
|
* historical relationship between high and batch.
|
|
*/
|
|
high = max(high, batch << 2);
|
|
|
|
return high;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* pcp->high and pcp->batch values are related and generally batch is lower
|
|
* than high. They are also related to pcp->count such that count is lower
|
|
* than high, and as soon as it reaches high, the pcplist is flushed.
|
|
*
|
|
* However, guaranteeing these relations at all times would require e.g. write
|
|
* barriers here but also careful usage of read barriers at the read side, and
|
|
* thus be prone to error and bad for performance. Thus the update only prevents
|
|
* store tearing. Any new users of pcp->batch, pcp->high_min and pcp->high_max
|
|
* should ensure they can cope with those fields changing asynchronously, and
|
|
* fully trust only the pcp->count field on the local CPU with interrupts
|
|
* disabled.
|
|
*
|
|
* mutex_is_locked(&pcp_batch_high_lock) required when calling this function
|
|
* outside of boot time (or some other assurance that no concurrent updaters
|
|
* exist).
|
|
*/
|
|
static void pageset_update(struct per_cpu_pages *pcp, unsigned long high_min,
|
|
unsigned long high_max, unsigned long batch)
|
|
{
|
|
WRITE_ONCE(pcp->batch, batch);
|
|
WRITE_ONCE(pcp->high_min, high_min);
|
|
WRITE_ONCE(pcp->high_max, high_max);
|
|
}
|
|
|
|
static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats)
|
|
{
|
|
int pindex;
|
|
|
|
memset(pcp, 0, sizeof(*pcp));
|
|
memset(pzstats, 0, sizeof(*pzstats));
|
|
|
|
spin_lock_init(&pcp->lock);
|
|
for (pindex = 0; pindex < NR_PCP_LISTS; pindex++)
|
|
INIT_LIST_HEAD(&pcp->lists[pindex]);
|
|
|
|
/*
|
|
* Set batch and high values safe for a boot pageset. A true percpu
|
|
* pageset's initialization will update them subsequently. Here we don't
|
|
* need to be as careful as pageset_update() as nobody can access the
|
|
* pageset yet.
|
|
*/
|
|
pcp->high_min = BOOT_PAGESET_HIGH;
|
|
pcp->high_max = BOOT_PAGESET_HIGH;
|
|
pcp->batch = BOOT_PAGESET_BATCH;
|
|
pcp->free_count = 0;
|
|
}
|
|
|
|
static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high_min,
|
|
unsigned long high_max, unsigned long batch)
|
|
{
|
|
struct per_cpu_pages *pcp;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
|
|
pageset_update(pcp, high_min, high_max, batch);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Calculate and set new high and batch values for all per-cpu pagesets of a
|
|
* zone based on the zone's size.
|
|
*/
|
|
static void zone_set_pageset_high_and_batch(struct zone *zone, int cpu_online)
|
|
{
|
|
int new_high_min, new_high_max, new_batch;
|
|
|
|
new_batch = max(1, zone_batchsize(zone));
|
|
if (percpu_pagelist_high_fraction) {
|
|
new_high_min = zone_highsize(zone, new_batch, cpu_online,
|
|
percpu_pagelist_high_fraction);
|
|
/*
|
|
* PCP high is tuned manually, disable auto-tuning via
|
|
* setting high_min and high_max to the manual value.
|
|
*/
|
|
new_high_max = new_high_min;
|
|
} else {
|
|
new_high_min = zone_highsize(zone, new_batch, cpu_online, 0);
|
|
new_high_max = zone_highsize(zone, new_batch, cpu_online,
|
|
MIN_PERCPU_PAGELIST_HIGH_FRACTION);
|
|
}
|
|
|
|
if (zone->pageset_high_min == new_high_min &&
|
|
zone->pageset_high_max == new_high_max &&
|
|
zone->pageset_batch == new_batch)
|
|
return;
|
|
|
|
zone->pageset_high_min = new_high_min;
|
|
zone->pageset_high_max = new_high_max;
|
|
zone->pageset_batch = new_batch;
|
|
|
|
__zone_set_pageset_high_and_batch(zone, new_high_min, new_high_max,
|
|
new_batch);
|
|
}
|
|
|
|
void __meminit setup_zone_pageset(struct zone *zone)
|
|
{
|
|
int cpu;
|
|
|
|
/* Size may be 0 on !SMP && !NUMA */
|
|
if (sizeof(struct per_cpu_zonestat) > 0)
|
|
zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat);
|
|
|
|
zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages);
|
|
for_each_possible_cpu(cpu) {
|
|
struct per_cpu_pages *pcp;
|
|
struct per_cpu_zonestat *pzstats;
|
|
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
|
|
pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
|
|
per_cpu_pages_init(pcp, pzstats);
|
|
}
|
|
|
|
zone_set_pageset_high_and_batch(zone, 0);
|
|
}
|
|
|
|
/*
|
|
* The zone indicated has a new number of managed_pages; batch sizes and percpu
|
|
* page high values need to be recalculated.
|
|
*/
|
|
static void zone_pcp_update(struct zone *zone, int cpu_online)
|
|
{
|
|
mutex_lock(&pcp_batch_high_lock);
|
|
zone_set_pageset_high_and_batch(zone, cpu_online);
|
|
mutex_unlock(&pcp_batch_high_lock);
|
|
}
|
|
|
|
static void zone_pcp_update_cacheinfo(struct zone *zone, unsigned int cpu)
|
|
{
|
|
struct per_cpu_pages *pcp;
|
|
struct cpu_cacheinfo *cci;
|
|
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
|
|
cci = get_cpu_cacheinfo(cpu);
|
|
/*
|
|
* If data cache slice of CPU is large enough, "pcp->batch"
|
|
* pages can be preserved in PCP before draining PCP for
|
|
* consecutive high-order pages freeing without allocation.
|
|
* This can reduce zone lock contention without hurting
|
|
* cache-hot pages sharing.
|
|
*/
|
|
spin_lock(&pcp->lock);
|
|
if ((cci->per_cpu_data_slice_size >> PAGE_SHIFT) > 3 * pcp->batch)
|
|
pcp->flags |= PCPF_FREE_HIGH_BATCH;
|
|
else
|
|
pcp->flags &= ~PCPF_FREE_HIGH_BATCH;
|
|
spin_unlock(&pcp->lock);
|
|
}
|
|
|
|
void setup_pcp_cacheinfo(unsigned int cpu)
|
|
{
|
|
struct zone *zone;
|
|
|
|
for_each_populated_zone(zone)
|
|
zone_pcp_update_cacheinfo(zone, cpu);
|
|
}
|
|
|
|
/*
|
|
* Allocate per cpu pagesets and initialize them.
|
|
* Before this call only boot pagesets were available.
|
|
*/
|
|
void __init setup_per_cpu_pageset(void)
|
|
{
|
|
struct pglist_data *pgdat;
|
|
struct zone *zone;
|
|
int __maybe_unused cpu;
|
|
|
|
for_each_populated_zone(zone)
|
|
setup_zone_pageset(zone);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Unpopulated zones continue using the boot pagesets.
|
|
* The numa stats for these pagesets need to be reset.
|
|
* Otherwise, they will end up skewing the stats of
|
|
* the nodes these zones are associated with.
|
|
*/
|
|
for_each_possible_cpu(cpu) {
|
|
struct per_cpu_zonestat *pzstats = &per_cpu(boot_zonestats, cpu);
|
|
memset(pzstats->vm_numa_event, 0,
|
|
sizeof(pzstats->vm_numa_event));
|
|
}
|
|
#endif
|
|
|
|
for_each_online_pgdat(pgdat)
|
|
pgdat->per_cpu_nodestats =
|
|
alloc_percpu(struct per_cpu_nodestat);
|
|
}
|
|
|
|
__meminit void zone_pcp_init(struct zone *zone)
|
|
{
|
|
/*
|
|
* per cpu subsystem is not up at this point. The following code
|
|
* relies on the ability of the linker to provide the
|
|
* offset of a (static) per cpu variable into the per cpu area.
|
|
*/
|
|
zone->per_cpu_pageset = &boot_pageset;
|
|
zone->per_cpu_zonestats = &boot_zonestats;
|
|
zone->pageset_high_min = BOOT_PAGESET_HIGH;
|
|
zone->pageset_high_max = BOOT_PAGESET_HIGH;
|
|
zone->pageset_batch = BOOT_PAGESET_BATCH;
|
|
|
|
if (populated_zone(zone))
|
|
pr_debug(" %s zone: %lu pages, LIFO batch:%u\n", zone->name,
|
|
zone->present_pages, zone_batchsize(zone));
|
|
}
|
|
|
|
void adjust_managed_page_count(struct page *page, long count)
|
|
{
|
|
atomic_long_add(count, &page_zone(page)->managed_pages);
|
|
totalram_pages_add(count);
|
|
}
|
|
EXPORT_SYMBOL(adjust_managed_page_count);
|
|
|
|
unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
|
|
{
|
|
void *pos;
|
|
unsigned long pages = 0;
|
|
|
|
start = (void *)PAGE_ALIGN((unsigned long)start);
|
|
end = (void *)((unsigned long)end & PAGE_MASK);
|
|
for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
|
|
struct page *page = virt_to_page(pos);
|
|
void *direct_map_addr;
|
|
|
|
/*
|
|
* 'direct_map_addr' might be different from 'pos'
|
|
* because some architectures' virt_to_page()
|
|
* work with aliases. Getting the direct map
|
|
* address ensures that we get a _writeable_
|
|
* alias for the memset().
|
|
*/
|
|
direct_map_addr = page_address(page);
|
|
/*
|
|
* Perform a kasan-unchecked memset() since this memory
|
|
* has not been initialized.
|
|
*/
|
|
direct_map_addr = kasan_reset_tag(direct_map_addr);
|
|
if ((unsigned int)poison <= 0xFF)
|
|
memset(direct_map_addr, poison, PAGE_SIZE);
|
|
|
|
free_reserved_page(page);
|
|
}
|
|
|
|
if (pages && s)
|
|
pr_info("Freeing %s memory: %ldK\n", s, K(pages));
|
|
|
|
return pages;
|
|
}
|
|
|
|
void free_reserved_page(struct page *page)
|
|
{
|
|
clear_page_tag_ref(page);
|
|
ClearPageReserved(page);
|
|
init_page_count(page);
|
|
__free_page(page);
|
|
adjust_managed_page_count(page, 1);
|
|
}
|
|
EXPORT_SYMBOL(free_reserved_page);
|
|
|
|
static int page_alloc_cpu_dead(unsigned int cpu)
|
|
{
|
|
struct zone *zone;
|
|
|
|
lru_add_drain_cpu(cpu);
|
|
mlock_drain_remote(cpu);
|
|
drain_pages(cpu);
|
|
|
|
/*
|
|
* Spill the event counters of the dead processor
|
|
* into the current processors event counters.
|
|
* This artificially elevates the count of the current
|
|
* processor.
|
|
*/
|
|
vm_events_fold_cpu(cpu);
|
|
|
|
/*
|
|
* Zero the differential counters of the dead processor
|
|
* so that the vm statistics are consistent.
|
|
*
|
|
* This is only okay since the processor is dead and cannot
|
|
* race with what we are doing.
|
|
*/
|
|
cpu_vm_stats_fold(cpu);
|
|
|
|
for_each_populated_zone(zone)
|
|
zone_pcp_update(zone, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int page_alloc_cpu_online(unsigned int cpu)
|
|
{
|
|
struct zone *zone;
|
|
|
|
for_each_populated_zone(zone)
|
|
zone_pcp_update(zone, 1);
|
|
return 0;
|
|
}
|
|
|
|
void __init page_alloc_init_cpuhp(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC,
|
|
"mm/page_alloc:pcp",
|
|
page_alloc_cpu_online,
|
|
page_alloc_cpu_dead);
|
|
WARN_ON(ret < 0);
|
|
}
|
|
|
|
/*
|
|
* calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
|
|
* or min_free_kbytes changes.
|
|
*/
|
|
static void calculate_totalreserve_pages(void)
|
|
{
|
|
struct pglist_data *pgdat;
|
|
unsigned long reserve_pages = 0;
|
|
enum zone_type i, j;
|
|
|
|
for_each_online_pgdat(pgdat) {
|
|
|
|
pgdat->totalreserve_pages = 0;
|
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) {
|
|
struct zone *zone = pgdat->node_zones + i;
|
|
long max = 0;
|
|
unsigned long managed_pages = zone_managed_pages(zone);
|
|
|
|
/* Find valid and maximum lowmem_reserve in the zone */
|
|
for (j = i; j < MAX_NR_ZONES; j++) {
|
|
if (zone->lowmem_reserve[j] > max)
|
|
max = zone->lowmem_reserve[j];
|
|
}
|
|
|
|
/* we treat the high watermark as reserved pages. */
|
|
max += high_wmark_pages(zone);
|
|
|
|
if (max > managed_pages)
|
|
max = managed_pages;
|
|
|
|
pgdat->totalreserve_pages += max;
|
|
|
|
reserve_pages += max;
|
|
}
|
|
}
|
|
totalreserve_pages = reserve_pages;
|
|
}
|
|
|
|
/*
|
|
* setup_per_zone_lowmem_reserve - called whenever
|
|
* sysctl_lowmem_reserve_ratio changes. Ensures that each zone
|
|
* has a correct pages reserved value, so an adequate number of
|
|
* pages are left in the zone after a successful __alloc_pages().
|
|
*/
|
|
static void setup_per_zone_lowmem_reserve(void)
|
|
{
|
|
struct pglist_data *pgdat;
|
|
enum zone_type i, j;
|
|
|
|
for_each_online_pgdat(pgdat) {
|
|
for (i = 0; i < MAX_NR_ZONES - 1; i++) {
|
|
struct zone *zone = &pgdat->node_zones[i];
|
|
int ratio = sysctl_lowmem_reserve_ratio[i];
|
|
bool clear = !ratio || !zone_managed_pages(zone);
|
|
unsigned long managed_pages = 0;
|
|
|
|
for (j = i + 1; j < MAX_NR_ZONES; j++) {
|
|
struct zone *upper_zone = &pgdat->node_zones[j];
|
|
bool empty = !zone_managed_pages(upper_zone);
|
|
|
|
managed_pages += zone_managed_pages(upper_zone);
|
|
|
|
if (clear || empty)
|
|
zone->lowmem_reserve[j] = 0;
|
|
else
|
|
zone->lowmem_reserve[j] = managed_pages / ratio;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* update totalreserve_pages */
|
|
calculate_totalreserve_pages();
|
|
}
|
|
|
|
static void __setup_per_zone_wmarks(void)
|
|
{
|
|
unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
|
|
unsigned long lowmem_pages = 0;
|
|
struct zone *zone;
|
|
unsigned long flags;
|
|
|
|
/* Calculate total number of !ZONE_HIGHMEM and !ZONE_MOVABLE pages */
|
|
for_each_zone(zone) {
|
|
if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE)
|
|
lowmem_pages += zone_managed_pages(zone);
|
|
}
|
|
|
|
for_each_zone(zone) {
|
|
u64 tmp;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
tmp = (u64)pages_min * zone_managed_pages(zone);
|
|
tmp = div64_ul(tmp, lowmem_pages);
|
|
if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) {
|
|
/*
|
|
* __GFP_HIGH and PF_MEMALLOC allocations usually don't
|
|
* need highmem and movable zones pages, so cap pages_min
|
|
* to a small value here.
|
|
*
|
|
* The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
|
|
* deltas control async page reclaim, and so should
|
|
* not be capped for highmem and movable zones.
|
|
*/
|
|
unsigned long min_pages;
|
|
|
|
min_pages = zone_managed_pages(zone) / 1024;
|
|
min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
|
|
zone->_watermark[WMARK_MIN] = min_pages;
|
|
} else {
|
|
/*
|
|
* If it's a lowmem zone, reserve a number of pages
|
|
* proportionate to the zone's size.
|
|
*/
|
|
zone->_watermark[WMARK_MIN] = tmp;
|
|
}
|
|
|
|
/*
|
|
* Set the kswapd watermarks distance according to the
|
|
* scale factor in proportion to available memory, but
|
|
* ensure a minimum size on small systems.
|
|
*/
|
|
tmp = max_t(u64, tmp >> 2,
|
|
mult_frac(zone_managed_pages(zone),
|
|
watermark_scale_factor, 10000));
|
|
|
|
zone->watermark_boost = 0;
|
|
zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
|
|
zone->_watermark[WMARK_HIGH] = low_wmark_pages(zone) + tmp;
|
|
zone->_watermark[WMARK_PROMO] = high_wmark_pages(zone) + tmp;
|
|
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
|
|
/* update totalreserve_pages */
|
|
calculate_totalreserve_pages();
|
|
}
|
|
|
|
/**
|
|
* setup_per_zone_wmarks - called when min_free_kbytes changes
|
|
* or when memory is hot-{added|removed}
|
|
*
|
|
* Ensures that the watermark[min,low,high] values for each zone are set
|
|
* correctly with respect to min_free_kbytes.
|
|
*/
|
|
void setup_per_zone_wmarks(void)
|
|
{
|
|
struct zone *zone;
|
|
static DEFINE_SPINLOCK(lock);
|
|
|
|
spin_lock(&lock);
|
|
__setup_per_zone_wmarks();
|
|
spin_unlock(&lock);
|
|
|
|
/*
|
|
* The watermark size have changed so update the pcpu batch
|
|
* and high limits or the limits may be inappropriate.
|
|
*/
|
|
for_each_zone(zone)
|
|
zone_pcp_update(zone, 0);
|
|
}
|
|
|
|
/*
|
|
* Initialise min_free_kbytes.
|
|
*
|
|
* For small machines we want it small (128k min). For large machines
|
|
* we want it large (256MB max). But it is not linear, because network
|
|
* bandwidth does not increase linearly with machine size. We use
|
|
*
|
|
* min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
|
|
* min_free_kbytes = sqrt(lowmem_kbytes * 16)
|
|
*
|
|
* which yields
|
|
*
|
|
* 16MB: 512k
|
|
* 32MB: 724k
|
|
* 64MB: 1024k
|
|
* 128MB: 1448k
|
|
* 256MB: 2048k
|
|
* 512MB: 2896k
|
|
* 1024MB: 4096k
|
|
* 2048MB: 5792k
|
|
* 4096MB: 8192k
|
|
* 8192MB: 11584k
|
|
* 16384MB: 16384k
|
|
*/
|
|
void calculate_min_free_kbytes(void)
|
|
{
|
|
unsigned long lowmem_kbytes;
|
|
int new_min_free_kbytes;
|
|
|
|
lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
|
|
new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
|
|
|
|
if (new_min_free_kbytes > user_min_free_kbytes)
|
|
min_free_kbytes = clamp(new_min_free_kbytes, 128, 262144);
|
|
else
|
|
pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
|
|
new_min_free_kbytes, user_min_free_kbytes);
|
|
|
|
}
|
|
|
|
int __meminit init_per_zone_wmark_min(void)
|
|
{
|
|
calculate_min_free_kbytes();
|
|
setup_per_zone_wmarks();
|
|
refresh_zone_stat_thresholds();
|
|
setup_per_zone_lowmem_reserve();
|
|
|
|
#ifdef CONFIG_NUMA
|
|
setup_min_unmapped_ratio();
|
|
setup_min_slab_ratio();
|
|
#endif
|
|
|
|
khugepaged_min_free_kbytes_update();
|
|
|
|
return 0;
|
|
}
|
|
postcore_initcall(init_per_zone_wmark_min)
|
|
|
|
/*
|
|
* min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
|
|
* that we can call two helper functions whenever min_free_kbytes
|
|
* changes.
|
|
*/
|
|
static int min_free_kbytes_sysctl_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int rc;
|
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (rc)
|
|
return rc;
|
|
|
|
if (write) {
|
|
user_min_free_kbytes = min_free_kbytes;
|
|
setup_per_zone_wmarks();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int watermark_scale_factor_sysctl_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int rc;
|
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (rc)
|
|
return rc;
|
|
|
|
if (write)
|
|
setup_per_zone_wmarks();
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static void setup_min_unmapped_ratio(void)
|
|
{
|
|
pg_data_t *pgdat;
|
|
struct zone *zone;
|
|
|
|
for_each_online_pgdat(pgdat)
|
|
pgdat->min_unmapped_pages = 0;
|
|
|
|
for_each_zone(zone)
|
|
zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) *
|
|
sysctl_min_unmapped_ratio) / 100;
|
|
}
|
|
|
|
|
|
static int sysctl_min_unmapped_ratio_sysctl_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int rc;
|
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (rc)
|
|
return rc;
|
|
|
|
setup_min_unmapped_ratio();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void setup_min_slab_ratio(void)
|
|
{
|
|
pg_data_t *pgdat;
|
|
struct zone *zone;
|
|
|
|
for_each_online_pgdat(pgdat)
|
|
pgdat->min_slab_pages = 0;
|
|
|
|
for_each_zone(zone)
|
|
zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) *
|
|
sysctl_min_slab_ratio) / 100;
|
|
}
|
|
|
|
static int sysctl_min_slab_ratio_sysctl_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int rc;
|
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (rc)
|
|
return rc;
|
|
|
|
setup_min_slab_ratio();
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* lowmem_reserve_ratio_sysctl_handler - just a wrapper around
|
|
* proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
|
|
* whenever sysctl_lowmem_reserve_ratio changes.
|
|
*
|
|
* The reserve ratio obviously has absolutely no relation with the
|
|
* minimum watermarks. The lowmem reserve ratio can only make sense
|
|
* if in function of the boot time zone sizes.
|
|
*/
|
|
static int lowmem_reserve_ratio_sysctl_handler(const struct ctl_table *table,
|
|
int write, void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int i;
|
|
|
|
proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) {
|
|
if (sysctl_lowmem_reserve_ratio[i] < 1)
|
|
sysctl_lowmem_reserve_ratio[i] = 0;
|
|
}
|
|
|
|
setup_per_zone_lowmem_reserve();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* percpu_pagelist_high_fraction - changes the pcp->high for each zone on each
|
|
* cpu. It is the fraction of total pages in each zone that a hot per cpu
|
|
* pagelist can have before it gets flushed back to buddy allocator.
|
|
*/
|
|
static int percpu_pagelist_high_fraction_sysctl_handler(const struct ctl_table *table,
|
|
int write, void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
struct zone *zone;
|
|
int old_percpu_pagelist_high_fraction;
|
|
int ret;
|
|
|
|
mutex_lock(&pcp_batch_high_lock);
|
|
old_percpu_pagelist_high_fraction = percpu_pagelist_high_fraction;
|
|
|
|
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (!write || ret < 0)
|
|
goto out;
|
|
|
|
/* Sanity checking to avoid pcp imbalance */
|
|
if (percpu_pagelist_high_fraction &&
|
|
percpu_pagelist_high_fraction < MIN_PERCPU_PAGELIST_HIGH_FRACTION) {
|
|
percpu_pagelist_high_fraction = old_percpu_pagelist_high_fraction;
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* No change? */
|
|
if (percpu_pagelist_high_fraction == old_percpu_pagelist_high_fraction)
|
|
goto out;
|
|
|
|
for_each_populated_zone(zone)
|
|
zone_set_pageset_high_and_batch(zone, 0);
|
|
out:
|
|
mutex_unlock(&pcp_batch_high_lock);
|
|
return ret;
|
|
}
|
|
|
|
static struct ctl_table page_alloc_sysctl_table[] = {
|
|
{
|
|
.procname = "min_free_kbytes",
|
|
.data = &min_free_kbytes,
|
|
.maxlen = sizeof(min_free_kbytes),
|
|
.mode = 0644,
|
|
.proc_handler = min_free_kbytes_sysctl_handler,
|
|
.extra1 = SYSCTL_ZERO,
|
|
},
|
|
{
|
|
.procname = "watermark_boost_factor",
|
|
.data = &watermark_boost_factor,
|
|
.maxlen = sizeof(watermark_boost_factor),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_minmax,
|
|
.extra1 = SYSCTL_ZERO,
|
|
},
|
|
{
|
|
.procname = "watermark_scale_factor",
|
|
.data = &watermark_scale_factor,
|
|
.maxlen = sizeof(watermark_scale_factor),
|
|
.mode = 0644,
|
|
.proc_handler = watermark_scale_factor_sysctl_handler,
|
|
.extra1 = SYSCTL_ONE,
|
|
.extra2 = SYSCTL_THREE_THOUSAND,
|
|
},
|
|
{
|
|
.procname = "percpu_pagelist_high_fraction",
|
|
.data = &percpu_pagelist_high_fraction,
|
|
.maxlen = sizeof(percpu_pagelist_high_fraction),
|
|
.mode = 0644,
|
|
.proc_handler = percpu_pagelist_high_fraction_sysctl_handler,
|
|
.extra1 = SYSCTL_ZERO,
|
|
},
|
|
{
|
|
.procname = "lowmem_reserve_ratio",
|
|
.data = &sysctl_lowmem_reserve_ratio,
|
|
.maxlen = sizeof(sysctl_lowmem_reserve_ratio),
|
|
.mode = 0644,
|
|
.proc_handler = lowmem_reserve_ratio_sysctl_handler,
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.procname = "numa_zonelist_order",
|
|
.data = &numa_zonelist_order,
|
|
.maxlen = NUMA_ZONELIST_ORDER_LEN,
|
|
.mode = 0644,
|
|
.proc_handler = numa_zonelist_order_handler,
|
|
},
|
|
{
|
|
.procname = "min_unmapped_ratio",
|
|
.data = &sysctl_min_unmapped_ratio,
|
|
.maxlen = sizeof(sysctl_min_unmapped_ratio),
|
|
.mode = 0644,
|
|
.proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
|
|
.extra1 = SYSCTL_ZERO,
|
|
.extra2 = SYSCTL_ONE_HUNDRED,
|
|
},
|
|
{
|
|
.procname = "min_slab_ratio",
|
|
.data = &sysctl_min_slab_ratio,
|
|
.maxlen = sizeof(sysctl_min_slab_ratio),
|
|
.mode = 0644,
|
|
.proc_handler = sysctl_min_slab_ratio_sysctl_handler,
|
|
.extra1 = SYSCTL_ZERO,
|
|
.extra2 = SYSCTL_ONE_HUNDRED,
|
|
},
|
|
#endif
|
|
};
|
|
|
|
void __init page_alloc_sysctl_init(void)
|
|
{
|
|
register_sysctl_init("vm", page_alloc_sysctl_table);
|
|
}
|
|
|
|
#ifdef CONFIG_CONTIG_ALLOC
|
|
/* Usage: See admin-guide/dynamic-debug-howto.rst */
|
|
static void alloc_contig_dump_pages(struct list_head *page_list)
|
|
{
|
|
DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, "migrate failure");
|
|
|
|
if (DYNAMIC_DEBUG_BRANCH(descriptor)) {
|
|
struct page *page;
|
|
|
|
dump_stack();
|
|
list_for_each_entry(page, page_list, lru)
|
|
dump_page(page, "migration failure");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* [start, end) must belong to a single zone.
|
|
* @migratetype: using migratetype to filter the type of migration in
|
|
* trace_mm_alloc_contig_migrate_range_info.
|
|
*/
|
|
static int __alloc_contig_migrate_range(struct compact_control *cc,
|
|
unsigned long start, unsigned long end, int migratetype)
|
|
{
|
|
/* This function is based on compact_zone() from compaction.c. */
|
|
unsigned int nr_reclaimed;
|
|
unsigned long pfn = start;
|
|
unsigned int tries = 0;
|
|
int ret = 0;
|
|
struct migration_target_control mtc = {
|
|
.nid = zone_to_nid(cc->zone),
|
|
.gfp_mask = cc->gfp_mask,
|
|
.reason = MR_CONTIG_RANGE,
|
|
};
|
|
struct page *page;
|
|
unsigned long total_mapped = 0;
|
|
unsigned long total_migrated = 0;
|
|
unsigned long total_reclaimed = 0;
|
|
|
|
lru_cache_disable();
|
|
|
|
while (pfn < end || !list_empty(&cc->migratepages)) {
|
|
if (fatal_signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
|
|
if (list_empty(&cc->migratepages)) {
|
|
cc->nr_migratepages = 0;
|
|
ret = isolate_migratepages_range(cc, pfn, end);
|
|
if (ret && ret != -EAGAIN)
|
|
break;
|
|
pfn = cc->migrate_pfn;
|
|
tries = 0;
|
|
} else if (++tries == 5) {
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
|
|
nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
|
|
&cc->migratepages);
|
|
cc->nr_migratepages -= nr_reclaimed;
|
|
|
|
if (trace_mm_alloc_contig_migrate_range_info_enabled()) {
|
|
total_reclaimed += nr_reclaimed;
|
|
list_for_each_entry(page, &cc->migratepages, lru) {
|
|
struct folio *folio = page_folio(page);
|
|
|
|
total_mapped += folio_mapped(folio) *
|
|
folio_nr_pages(folio);
|
|
}
|
|
}
|
|
|
|
ret = migrate_pages(&cc->migratepages, alloc_migration_target,
|
|
NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE, NULL);
|
|
|
|
if (trace_mm_alloc_contig_migrate_range_info_enabled() && !ret)
|
|
total_migrated += cc->nr_migratepages;
|
|
|
|
/*
|
|
* On -ENOMEM, migrate_pages() bails out right away. It is pointless
|
|
* to retry again over this error, so do the same here.
|
|
*/
|
|
if (ret == -ENOMEM)
|
|
break;
|
|
}
|
|
|
|
lru_cache_enable();
|
|
if (ret < 0) {
|
|
if (!(cc->gfp_mask & __GFP_NOWARN) && ret == -EBUSY)
|
|
alloc_contig_dump_pages(&cc->migratepages);
|
|
putback_movable_pages(&cc->migratepages);
|
|
}
|
|
|
|
trace_mm_alloc_contig_migrate_range_info(start, end, migratetype,
|
|
total_migrated,
|
|
total_reclaimed,
|
|
total_mapped);
|
|
return (ret < 0) ? ret : 0;
|
|
}
|
|
|
|
static void split_free_pages(struct list_head *list, gfp_t gfp_mask)
|
|
{
|
|
int order;
|
|
|
|
for (order = 0; order < NR_PAGE_ORDERS; order++) {
|
|
struct page *page, *next;
|
|
int nr_pages = 1 << order;
|
|
|
|
list_for_each_entry_safe(page, next, &list[order], lru) {
|
|
int i;
|
|
|
|
post_alloc_hook(page, order, gfp_mask);
|
|
set_page_refcounted(page);
|
|
if (!order)
|
|
continue;
|
|
|
|
split_page(page, order);
|
|
|
|
/* Add all subpages to the order-0 head, in sequence. */
|
|
list_del(&page->lru);
|
|
for (i = 0; i < nr_pages; i++)
|
|
list_add_tail(&page[i].lru, &list[0]);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int __alloc_contig_verify_gfp_mask(gfp_t gfp_mask, gfp_t *gfp_cc_mask)
|
|
{
|
|
const gfp_t reclaim_mask = __GFP_IO | __GFP_FS | __GFP_RECLAIM;
|
|
const gfp_t action_mask = __GFP_COMP | __GFP_RETRY_MAYFAIL | __GFP_NOWARN |
|
|
__GFP_ZERO | __GFP_ZEROTAGS | __GFP_SKIP_ZERO;
|
|
const gfp_t cc_action_mask = __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
|
|
|
|
/*
|
|
* We are given the range to allocate; node, mobility and placement
|
|
* hints are irrelevant at this point. We'll simply ignore them.
|
|
*/
|
|
gfp_mask &= ~(GFP_ZONEMASK | __GFP_RECLAIMABLE | __GFP_WRITE |
|
|
__GFP_HARDWALL | __GFP_THISNODE | __GFP_MOVABLE);
|
|
|
|
/*
|
|
* We only support most reclaim flags (but not NOFAIL/NORETRY), and
|
|
* selected action flags.
|
|
*/
|
|
if (gfp_mask & ~(reclaim_mask | action_mask))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Flags to control page compaction/migration/reclaim, to free up our
|
|
* page range. Migratable pages are movable, __GFP_MOVABLE is implied
|
|
* for them.
|
|
*
|
|
* Traditionally we always had __GFP_RETRY_MAYFAIL set, keep doing that
|
|
* to not degrade callers.
|
|
*/
|
|
*gfp_cc_mask = (gfp_mask & (reclaim_mask | cc_action_mask)) |
|
|
__GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* alloc_contig_range() -- tries to allocate given range of pages
|
|
* @start: start PFN to allocate
|
|
* @end: one-past-the-last PFN to allocate
|
|
* @migratetype: migratetype of the underlying pageblocks (either
|
|
* #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
|
|
* in range must have the same migratetype and it must
|
|
* be either of the two.
|
|
* @gfp_mask: GFP mask. Node/zone/placement hints are ignored; only some
|
|
* action and reclaim modifiers are supported. Reclaim modifiers
|
|
* control allocation behavior during compaction/migration/reclaim.
|
|
*
|
|
* The PFN range does not have to be pageblock aligned. The PFN range must
|
|
* belong to a single zone.
|
|
*
|
|
* The first thing this routine does is attempt to MIGRATE_ISOLATE all
|
|
* pageblocks in the range. Once isolated, the pageblocks should not
|
|
* be modified by others.
|
|
*
|
|
* Return: zero on success or negative error code. On success all
|
|
* pages which PFN is in [start, end) are allocated for the caller and
|
|
* need to be freed with free_contig_range().
|
|
*/
|
|
int alloc_contig_range_noprof(unsigned long start, unsigned long end,
|
|
unsigned migratetype, gfp_t gfp_mask)
|
|
{
|
|
unsigned long outer_start, outer_end;
|
|
int ret = 0;
|
|
|
|
struct compact_control cc = {
|
|
.nr_migratepages = 0,
|
|
.order = -1,
|
|
.zone = page_zone(pfn_to_page(start)),
|
|
.mode = MIGRATE_SYNC,
|
|
.ignore_skip_hint = true,
|
|
.no_set_skip_hint = true,
|
|
.alloc_contig = true,
|
|
};
|
|
INIT_LIST_HEAD(&cc.migratepages);
|
|
|
|
gfp_mask = current_gfp_context(gfp_mask);
|
|
if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* What we do here is we mark all pageblocks in range as
|
|
* MIGRATE_ISOLATE. Because pageblock and max order pages may
|
|
* have different sizes, and due to the way page allocator
|
|
* work, start_isolate_page_range() has special handlings for this.
|
|
*
|
|
* Once the pageblocks are marked as MIGRATE_ISOLATE, we
|
|
* migrate the pages from an unaligned range (ie. pages that
|
|
* we are interested in). This will put all the pages in
|
|
* range back to page allocator as MIGRATE_ISOLATE.
|
|
*
|
|
* When this is done, we take the pages in range from page
|
|
* allocator removing them from the buddy system. This way
|
|
* page allocator will never consider using them.
|
|
*
|
|
* This lets us mark the pageblocks back as
|
|
* MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
|
|
* aligned range but not in the unaligned, original range are
|
|
* put back to page allocator so that buddy can use them.
|
|
*/
|
|
|
|
ret = start_isolate_page_range(start, end, migratetype, 0);
|
|
if (ret)
|
|
goto done;
|
|
|
|
drain_all_pages(cc.zone);
|
|
|
|
/*
|
|
* In case of -EBUSY, we'd like to know which page causes problem.
|
|
* So, just fall through. test_pages_isolated() has a tracepoint
|
|
* which will report the busy page.
|
|
*
|
|
* It is possible that busy pages could become available before
|
|
* the call to test_pages_isolated, and the range will actually be
|
|
* allocated. So, if we fall through be sure to clear ret so that
|
|
* -EBUSY is not accidentally used or returned to caller.
|
|
*/
|
|
ret = __alloc_contig_migrate_range(&cc, start, end, migratetype);
|
|
if (ret && ret != -EBUSY)
|
|
goto done;
|
|
|
|
/*
|
|
* When in-use hugetlb pages are migrated, they may simply be released
|
|
* back into the free hugepage pool instead of being returned to the
|
|
* buddy system. After the migration of in-use huge pages is completed,
|
|
* we will invoke replace_free_hugepage_folios() to ensure that these
|
|
* hugepages are properly released to the buddy system.
|
|
*/
|
|
ret = replace_free_hugepage_folios(start, end);
|
|
if (ret)
|
|
goto done;
|
|
|
|
/*
|
|
* Pages from [start, end) are within a pageblock_nr_pages
|
|
* aligned blocks that are marked as MIGRATE_ISOLATE. What's
|
|
* more, all pages in [start, end) are free in page allocator.
|
|
* What we are going to do is to allocate all pages from
|
|
* [start, end) (that is remove them from page allocator).
|
|
*
|
|
* The only problem is that pages at the beginning and at the
|
|
* end of interesting range may be not aligned with pages that
|
|
* page allocator holds, ie. they can be part of higher order
|
|
* pages. Because of this, we reserve the bigger range and
|
|
* once this is done free the pages we are not interested in.
|
|
*
|
|
* We don't have to hold zone->lock here because the pages are
|
|
* isolated thus they won't get removed from buddy.
|
|
*/
|
|
outer_start = find_large_buddy(start);
|
|
|
|
/* Make sure the range is really isolated. */
|
|
if (test_pages_isolated(outer_start, end, 0)) {
|
|
ret = -EBUSY;
|
|
goto done;
|
|
}
|
|
|
|
/* Grab isolated pages from freelists. */
|
|
outer_end = isolate_freepages_range(&cc, outer_start, end);
|
|
if (!outer_end) {
|
|
ret = -EBUSY;
|
|
goto done;
|
|
}
|
|
|
|
if (!(gfp_mask & __GFP_COMP)) {
|
|
split_free_pages(cc.freepages, gfp_mask);
|
|
|
|
/* Free head and tail (if any) */
|
|
if (start != outer_start)
|
|
free_contig_range(outer_start, start - outer_start);
|
|
if (end != outer_end)
|
|
free_contig_range(end, outer_end - end);
|
|
} else if (start == outer_start && end == outer_end && is_power_of_2(end - start)) {
|
|
struct page *head = pfn_to_page(start);
|
|
int order = ilog2(end - start);
|
|
|
|
check_new_pages(head, order);
|
|
prep_new_page(head, order, gfp_mask, 0);
|
|
set_page_refcounted(head);
|
|
} else {
|
|
ret = -EINVAL;
|
|
WARN(true, "PFN range: requested [%lu, %lu), allocated [%lu, %lu)\n",
|
|
start, end, outer_start, outer_end);
|
|
}
|
|
done:
|
|
undo_isolate_page_range(start, end, migratetype);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(alloc_contig_range_noprof);
|
|
|
|
static int __alloc_contig_pages(unsigned long start_pfn,
|
|
unsigned long nr_pages, gfp_t gfp_mask)
|
|
{
|
|
unsigned long end_pfn = start_pfn + nr_pages;
|
|
|
|
return alloc_contig_range_noprof(start_pfn, end_pfn, MIGRATE_MOVABLE,
|
|
gfp_mask);
|
|
}
|
|
|
|
static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
|
|
unsigned long nr_pages)
|
|
{
|
|
unsigned long i, end_pfn = start_pfn + nr_pages;
|
|
struct page *page;
|
|
|
|
for (i = start_pfn; i < end_pfn; i++) {
|
|
page = pfn_to_online_page(i);
|
|
if (!page)
|
|
return false;
|
|
|
|
if (page_zone(page) != z)
|
|
return false;
|
|
|
|
if (PageReserved(page))
|
|
return false;
|
|
|
|
if (PageHuge(page))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static bool zone_spans_last_pfn(const struct zone *zone,
|
|
unsigned long start_pfn, unsigned long nr_pages)
|
|
{
|
|
unsigned long last_pfn = start_pfn + nr_pages - 1;
|
|
|
|
return zone_spans_pfn(zone, last_pfn);
|
|
}
|
|
|
|
/**
|
|
* alloc_contig_pages() -- tries to find and allocate contiguous range of pages
|
|
* @nr_pages: Number of contiguous pages to allocate
|
|
* @gfp_mask: GFP mask. Node/zone/placement hints limit the search; only some
|
|
* action and reclaim modifiers are supported. Reclaim modifiers
|
|
* control allocation behavior during compaction/migration/reclaim.
|
|
* @nid: Target node
|
|
* @nodemask: Mask for other possible nodes
|
|
*
|
|
* This routine is a wrapper around alloc_contig_range(). It scans over zones
|
|
* on an applicable zonelist to find a contiguous pfn range which can then be
|
|
* tried for allocation with alloc_contig_range(). This routine is intended
|
|
* for allocation requests which can not be fulfilled with the buddy allocator.
|
|
*
|
|
* The allocated memory is always aligned to a page boundary. If nr_pages is a
|
|
* power of two, then allocated range is also guaranteed to be aligned to same
|
|
* nr_pages (e.g. 1GB request would be aligned to 1GB).
|
|
*
|
|
* Allocated pages can be freed with free_contig_range() or by manually calling
|
|
* __free_page() on each allocated page.
|
|
*
|
|
* Return: pointer to contiguous pages on success, or NULL if not successful.
|
|
*/
|
|
struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nodemask)
|
|
{
|
|
unsigned long ret, pfn, flags;
|
|
struct zonelist *zonelist;
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
|
|
zonelist = node_zonelist(nid, gfp_mask);
|
|
for_each_zone_zonelist_nodemask(zone, z, zonelist,
|
|
gfp_zone(gfp_mask), nodemask) {
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
|
|
pfn = ALIGN(zone->zone_start_pfn, nr_pages);
|
|
while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
|
|
if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
|
|
/*
|
|
* We release the zone lock here because
|
|
* alloc_contig_range() will also lock the zone
|
|
* at some point. If there's an allocation
|
|
* spinning on this lock, it may win the race
|
|
* and cause alloc_contig_range() to fail...
|
|
*/
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
ret = __alloc_contig_pages(pfn, nr_pages,
|
|
gfp_mask);
|
|
if (!ret)
|
|
return pfn_to_page(pfn);
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
}
|
|
pfn += nr_pages;
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_CONTIG_ALLOC */
|
|
|
|
void free_contig_range(unsigned long pfn, unsigned long nr_pages)
|
|
{
|
|
unsigned long count = 0;
|
|
struct folio *folio = pfn_folio(pfn);
|
|
|
|
if (folio_test_large(folio)) {
|
|
int expected = folio_nr_pages(folio);
|
|
|
|
if (nr_pages == expected)
|
|
folio_put(folio);
|
|
else
|
|
WARN(true, "PFN %lu: nr_pages %lu != expected %d\n",
|
|
pfn, nr_pages, expected);
|
|
return;
|
|
}
|
|
|
|
for (; nr_pages--; pfn++) {
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
count += page_count(page) != 1;
|
|
__free_page(page);
|
|
}
|
|
WARN(count != 0, "%lu pages are still in use!\n", count);
|
|
}
|
|
EXPORT_SYMBOL(free_contig_range);
|
|
|
|
/*
|
|
* Effectively disable pcplists for the zone by setting the high limit to 0
|
|
* and draining all cpus. A concurrent page freeing on another CPU that's about
|
|
* to put the page on pcplist will either finish before the drain and the page
|
|
* will be drained, or observe the new high limit and skip the pcplist.
|
|
*
|
|
* Must be paired with a call to zone_pcp_enable().
|
|
*/
|
|
void zone_pcp_disable(struct zone *zone)
|
|
{
|
|
mutex_lock(&pcp_batch_high_lock);
|
|
__zone_set_pageset_high_and_batch(zone, 0, 0, 1);
|
|
__drain_all_pages(zone, true);
|
|
}
|
|
|
|
void zone_pcp_enable(struct zone *zone)
|
|
{
|
|
__zone_set_pageset_high_and_batch(zone, zone->pageset_high_min,
|
|
zone->pageset_high_max, zone->pageset_batch);
|
|
mutex_unlock(&pcp_batch_high_lock);
|
|
}
|
|
|
|
void zone_pcp_reset(struct zone *zone)
|
|
{
|
|
int cpu;
|
|
struct per_cpu_zonestat *pzstats;
|
|
|
|
if (zone->per_cpu_pageset != &boot_pageset) {
|
|
for_each_online_cpu(cpu) {
|
|
pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
|
|
drain_zonestat(zone, pzstats);
|
|
}
|
|
free_percpu(zone->per_cpu_pageset);
|
|
zone->per_cpu_pageset = &boot_pageset;
|
|
if (zone->per_cpu_zonestats != &boot_zonestats) {
|
|
free_percpu(zone->per_cpu_zonestats);
|
|
zone->per_cpu_zonestats = &boot_zonestats;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_HOTREMOVE
|
|
/*
|
|
* All pages in the range must be in a single zone, must not contain holes,
|
|
* must span full sections, and must be isolated before calling this function.
|
|
*
|
|
* Returns the number of managed (non-PageOffline()) pages in the range: the
|
|
* number of pages for which memory offlining code must adjust managed page
|
|
* counters using adjust_managed_page_count().
|
|
*/
|
|
unsigned long __offline_isolated_pages(unsigned long start_pfn,
|
|
unsigned long end_pfn)
|
|
{
|
|
unsigned long already_offline = 0, flags;
|
|
unsigned long pfn = start_pfn;
|
|
struct page *page;
|
|
struct zone *zone;
|
|
unsigned int order;
|
|
|
|
offline_mem_sections(pfn, end_pfn);
|
|
zone = page_zone(pfn_to_page(pfn));
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
while (pfn < end_pfn) {
|
|
page = pfn_to_page(pfn);
|
|
/*
|
|
* The HWPoisoned page may be not in buddy system, and
|
|
* page_count() is not 0.
|
|
*/
|
|
if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
|
|
pfn++;
|
|
continue;
|
|
}
|
|
/*
|
|
* At this point all remaining PageOffline() pages have a
|
|
* reference count of 0 and can simply be skipped.
|
|
*/
|
|
if (PageOffline(page)) {
|
|
BUG_ON(page_count(page));
|
|
BUG_ON(PageBuddy(page));
|
|
already_offline++;
|
|
pfn++;
|
|
continue;
|
|
}
|
|
|
|
BUG_ON(page_count(page));
|
|
BUG_ON(!PageBuddy(page));
|
|
VM_WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE);
|
|
order = buddy_order(page);
|
|
del_page_from_free_list(page, zone, order, MIGRATE_ISOLATE);
|
|
pfn += (1 << order);
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
|
|
return end_pfn - start_pfn - already_offline;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* This function returns a stable result only if called under zone lock.
|
|
*/
|
|
bool is_free_buddy_page(const struct page *page)
|
|
{
|
|
unsigned long pfn = page_to_pfn(page);
|
|
unsigned int order;
|
|
|
|
for (order = 0; order < NR_PAGE_ORDERS; order++) {
|
|
const struct page *head = page - (pfn & ((1 << order) - 1));
|
|
|
|
if (PageBuddy(head) &&
|
|
buddy_order_unsafe(head) >= order)
|
|
break;
|
|
}
|
|
|
|
return order <= MAX_PAGE_ORDER;
|
|
}
|
|
EXPORT_SYMBOL(is_free_buddy_page);
|
|
|
|
#ifdef CONFIG_MEMORY_FAILURE
|
|
static inline void add_to_free_list(struct page *page, struct zone *zone,
|
|
unsigned int order, int migratetype,
|
|
bool tail)
|
|
{
|
|
__add_to_free_list(page, zone, order, migratetype, tail);
|
|
account_freepages(zone, 1 << order, migratetype);
|
|
}
|
|
|
|
/*
|
|
* Break down a higher-order page in sub-pages, and keep our target out of
|
|
* buddy allocator.
|
|
*/
|
|
static void break_down_buddy_pages(struct zone *zone, struct page *page,
|
|
struct page *target, int low, int high,
|
|
int migratetype)
|
|
{
|
|
unsigned long size = 1 << high;
|
|
struct page *current_buddy;
|
|
|
|
while (high > low) {
|
|
high--;
|
|
size >>= 1;
|
|
|
|
if (target >= &page[size]) {
|
|
current_buddy = page;
|
|
page = page + size;
|
|
} else {
|
|
current_buddy = page + size;
|
|
}
|
|
|
|
if (set_page_guard(zone, current_buddy, high))
|
|
continue;
|
|
|
|
add_to_free_list(current_buddy, zone, high, migratetype, false);
|
|
set_buddy_order(current_buddy, high);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Take a page that will be marked as poisoned off the buddy allocator.
|
|
*/
|
|
bool take_page_off_buddy(struct page *page)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
unsigned long pfn = page_to_pfn(page);
|
|
unsigned long flags;
|
|
unsigned int order;
|
|
bool ret = false;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
for (order = 0; order < NR_PAGE_ORDERS; order++) {
|
|
struct page *page_head = page - (pfn & ((1 << order) - 1));
|
|
int page_order = buddy_order(page_head);
|
|
|
|
if (PageBuddy(page_head) && page_order >= order) {
|
|
unsigned long pfn_head = page_to_pfn(page_head);
|
|
int migratetype = get_pfnblock_migratetype(page_head,
|
|
pfn_head);
|
|
|
|
del_page_from_free_list(page_head, zone, page_order,
|
|
migratetype);
|
|
break_down_buddy_pages(zone, page_head, page, 0,
|
|
page_order, migratetype);
|
|
SetPageHWPoisonTakenOff(page);
|
|
ret = true;
|
|
break;
|
|
}
|
|
if (page_count(page_head) > 0)
|
|
break;
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Cancel takeoff done by take_page_off_buddy().
|
|
*/
|
|
bool put_page_back_buddy(struct page *page)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
unsigned long flags;
|
|
bool ret = false;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
if (put_page_testzero(page)) {
|
|
unsigned long pfn = page_to_pfn(page);
|
|
int migratetype = get_pfnblock_migratetype(page, pfn);
|
|
|
|
ClearPageHWPoisonTakenOff(page);
|
|
__free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE);
|
|
if (TestClearPageHWPoison(page)) {
|
|
ret = true;
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
bool has_managed_dma(void)
|
|
{
|
|
struct pglist_data *pgdat;
|
|
|
|
for_each_online_pgdat(pgdat) {
|
|
struct zone *zone = &pgdat->node_zones[ZONE_DMA];
|
|
|
|
if (managed_zone(zone))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_ZONE_DMA */
|
|
|
|
#ifdef CONFIG_UNACCEPTED_MEMORY
|
|
|
|
/* Counts number of zones with unaccepted pages. */
|
|
static DEFINE_STATIC_KEY_FALSE(zones_with_unaccepted_pages);
|
|
|
|
static bool lazy_accept = true;
|
|
|
|
static int __init accept_memory_parse(char *p)
|
|
{
|
|
if (!strcmp(p, "lazy")) {
|
|
lazy_accept = true;
|
|
return 0;
|
|
} else if (!strcmp(p, "eager")) {
|
|
lazy_accept = false;
|
|
return 0;
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
early_param("accept_memory", accept_memory_parse);
|
|
|
|
static bool page_contains_unaccepted(struct page *page, unsigned int order)
|
|
{
|
|
phys_addr_t start = page_to_phys(page);
|
|
|
|
return range_contains_unaccepted_memory(start, PAGE_SIZE << order);
|
|
}
|
|
|
|
static void __accept_page(struct zone *zone, unsigned long *flags,
|
|
struct page *page)
|
|
{
|
|
bool last;
|
|
|
|
list_del(&page->lru);
|
|
last = list_empty(&zone->unaccepted_pages);
|
|
|
|
account_freepages(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
|
|
__mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES);
|
|
__ClearPageUnaccepted(page);
|
|
spin_unlock_irqrestore(&zone->lock, *flags);
|
|
|
|
accept_memory(page_to_phys(page), PAGE_SIZE << MAX_PAGE_ORDER);
|
|
|
|
__free_pages_ok(page, MAX_PAGE_ORDER, FPI_TO_TAIL);
|
|
|
|
if (last)
|
|
static_branch_dec(&zones_with_unaccepted_pages);
|
|
}
|
|
|
|
void accept_page(struct page *page)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
if (!PageUnaccepted(page)) {
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Unlocks zone->lock */
|
|
__accept_page(zone, &flags, page);
|
|
}
|
|
|
|
static bool try_to_accept_memory_one(struct zone *zone)
|
|
{
|
|
unsigned long flags;
|
|
struct page *page;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
page = list_first_entry_or_null(&zone->unaccepted_pages,
|
|
struct page, lru);
|
|
if (!page) {
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
return false;
|
|
}
|
|
|
|
/* Unlocks zone->lock */
|
|
__accept_page(zone, &flags, page);
|
|
|
|
return true;
|
|
}
|
|
|
|
static inline bool has_unaccepted_memory(void)
|
|
{
|
|
return static_branch_unlikely(&zones_with_unaccepted_pages);
|
|
}
|
|
|
|
static bool cond_accept_memory(struct zone *zone, unsigned int order)
|
|
{
|
|
long to_accept;
|
|
bool ret = false;
|
|
|
|
if (!has_unaccepted_memory())
|
|
return false;
|
|
|
|
if (list_empty(&zone->unaccepted_pages))
|
|
return false;
|
|
|
|
/* How much to accept to get to promo watermark? */
|
|
to_accept = promo_wmark_pages(zone) -
|
|
(zone_page_state(zone, NR_FREE_PAGES) -
|
|
__zone_watermark_unusable_free(zone, order, 0) -
|
|
zone_page_state(zone, NR_UNACCEPTED));
|
|
|
|
while (to_accept > 0) {
|
|
if (!try_to_accept_memory_one(zone))
|
|
break;
|
|
ret = true;
|
|
to_accept -= MAX_ORDER_NR_PAGES;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool __free_unaccepted(struct page *page)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
unsigned long flags;
|
|
bool first = false;
|
|
|
|
if (!lazy_accept)
|
|
return false;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
first = list_empty(&zone->unaccepted_pages);
|
|
list_add_tail(&page->lru, &zone->unaccepted_pages);
|
|
account_freepages(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
|
|
__mod_zone_page_state(zone, NR_UNACCEPTED, MAX_ORDER_NR_PAGES);
|
|
__SetPageUnaccepted(page);
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
|
|
if (first)
|
|
static_branch_inc(&zones_with_unaccepted_pages);
|
|
|
|
return true;
|
|
}
|
|
|
|
#else
|
|
|
|
static bool page_contains_unaccepted(struct page *page, unsigned int order)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static bool cond_accept_memory(struct zone *zone, unsigned int order)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static bool __free_unaccepted(struct page *page)
|
|
{
|
|
BUILD_BUG();
|
|
return false;
|
|
}
|
|
|
|
#endif /* CONFIG_UNACCEPTED_MEMORY */
|