linux-next/include/linux/vm_event_item.h
Usama Arif dafff3f4c8 mm: split underused THPs
This is an attempt to mitigate the issue of running out of memory when THP
is always enabled.  During runtime whenever a THP is being faulted in
(__do_huge_pmd_anonymous_page) or collapsed by khugepaged
(collapse_huge_page), the THP is added to _deferred_list.  Whenever memory
reclaim happens in linux, the kernel runs the deferred_split shrinker
which goes through the _deferred_list.

If the folio was partially mapped, the shrinker attempts to split it.  If
the folio is not partially mapped, the shrinker checks if the THP was
underused, i.e.  how many of the base 4K pages of the entire THP were
zero-filled.  If this number goes above a certain threshold (decided by
/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none), the
shrinker will attempt to split that THP.  Then at remap time, the pages
that were zero-filled are mapped to the shared zeropage, hence saving
memory.

Link: https://lkml.kernel.org/r/20240830100438.3623486-6-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Suggested-by: Rik van Riel <riel@surriel.com>
Co-authored-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Zhu <alexlzhu@fb.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuang Zhai <zhais@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Shuang Zhai <szhai2@cs.rochester.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:04 -07:00

194 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef VM_EVENT_ITEM_H_INCLUDED
#define VM_EVENT_ITEM_H_INCLUDED
#ifdef CONFIG_ZONE_DMA
#define DMA_ZONE(xx) xx##_DMA,
#else
#define DMA_ZONE(xx)
#endif
#ifdef CONFIG_ZONE_DMA32
#define DMA32_ZONE(xx) xx##_DMA32,
#else
#define DMA32_ZONE(xx)
#endif
#ifdef CONFIG_HIGHMEM
#define HIGHMEM_ZONE(xx) xx##_HIGH,
#else
#define HIGHMEM_ZONE(xx)
#endif
#ifdef CONFIG_ZONE_DEVICE
#define DEVICE_ZONE(xx) xx##_DEVICE,
#else
#define DEVICE_ZONE(xx)
#endif
#define FOR_ALL_ZONES(xx) DMA_ZONE(xx) DMA32_ZONE(xx) xx##_NORMAL, \
HIGHMEM_ZONE(xx) xx##_MOVABLE, DEVICE_ZONE(xx)
enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
FOR_ALL_ZONES(PGALLOC)
FOR_ALL_ZONES(ALLOCSTALL)
FOR_ALL_ZONES(PGSCAN_SKIP)
PGFREE, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE,
PGFAULT, PGMAJFAULT,
PGLAZYFREED,
PGREFILL,
PGREUSE,
PGSTEAL_KSWAPD,
PGSTEAL_DIRECT,
PGSTEAL_KHUGEPAGED,
PGSCAN_KSWAPD,
PGSCAN_DIRECT,
PGSCAN_KHUGEPAGED,
PGSCAN_DIRECT_THROTTLE,
PGSCAN_ANON,
PGSCAN_FILE,
PGSTEAL_ANON,
PGSTEAL_FILE,
#ifdef CONFIG_NUMA
PGSCAN_ZONE_RECLAIM_SUCCESS,
PGSCAN_ZONE_RECLAIM_FAILED,
#endif
PGINODESTEAL, SLABS_SCANNED, KSWAPD_INODESTEAL,
KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY,
PAGEOUTRUN, PGROTATED,
DROP_PAGECACHE, DROP_SLAB,
OOM_KILL,
#ifdef CONFIG_NUMA_BALANCING
NUMA_PTE_UPDATES,
NUMA_HUGE_PTE_UPDATES,
NUMA_HINT_FAULTS,
NUMA_HINT_FAULTS_LOCAL,
NUMA_PAGE_MIGRATE,
#endif
#ifdef CONFIG_MIGRATION
PGMIGRATE_SUCCESS, PGMIGRATE_FAIL,
THP_MIGRATION_SUCCESS,
THP_MIGRATION_FAIL,
THP_MIGRATION_SPLIT,
#endif
#ifdef CONFIG_COMPACTION
COMPACTMIGRATE_SCANNED, COMPACTFREE_SCANNED,
COMPACTISOLATED,
COMPACTSTALL, COMPACTFAIL, COMPACTSUCCESS,
KCOMPACTD_WAKE,
KCOMPACTD_MIGRATE_SCANNED, KCOMPACTD_FREE_SCANNED,
#endif
#ifdef CONFIG_HUGETLB_PAGE
HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL,
#endif
#ifdef CONFIG_CMA
CMA_ALLOC_SUCCESS,
CMA_ALLOC_FAIL,
#endif
UNEVICTABLE_PGCULLED, /* culled to noreclaim list */
UNEVICTABLE_PGSCANNED, /* scanned for reclaimability */
UNEVICTABLE_PGRESCUED, /* rescued from noreclaim list */
UNEVICTABLE_PGMLOCKED,
UNEVICTABLE_PGMUNLOCKED,
UNEVICTABLE_PGCLEARED, /* on COW, page truncate */
UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
THP_FAULT_ALLOC,
THP_FAULT_FALLBACK,
THP_FAULT_FALLBACK_CHARGE,
THP_COLLAPSE_ALLOC,
THP_COLLAPSE_ALLOC_FAILED,
THP_FILE_ALLOC,
THP_FILE_FALLBACK,
THP_FILE_FALLBACK_CHARGE,
THP_FILE_MAPPED,
THP_SPLIT_PAGE,
THP_SPLIT_PAGE_FAILED,
THP_DEFERRED_SPLIT_PAGE,
THP_UNDERUSED_SPLIT_PAGE,
THP_SPLIT_PMD,
THP_SCAN_EXCEED_NONE_PTE,
THP_SCAN_EXCEED_SWAP_PTE,
THP_SCAN_EXCEED_SHARED_PTE,
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
THP_SPLIT_PUD,
#endif
THP_ZERO_PAGE_ALLOC,
THP_ZERO_PAGE_ALLOC_FAILED,
THP_SWPOUT,
THP_SWPOUT_FALLBACK,
#endif
#ifdef CONFIG_MEMORY_BALLOON
BALLOON_INFLATE,
BALLOON_DEFLATE,
#ifdef CONFIG_BALLOON_COMPACTION
BALLOON_MIGRATE,
#endif
#endif
#ifdef CONFIG_DEBUG_TLBFLUSH
NR_TLB_REMOTE_FLUSH, /* cpu tried to flush others' tlbs */
NR_TLB_REMOTE_FLUSH_RECEIVED,/* cpu received ipi for flush */
NR_TLB_LOCAL_FLUSH_ALL,
NR_TLB_LOCAL_FLUSH_ONE,
#endif /* CONFIG_DEBUG_TLBFLUSH */
#ifdef CONFIG_SWAP
SWAP_RA,
SWAP_RA_HIT,
#ifdef CONFIG_KSM
KSM_SWPIN_COPY,
#endif
#endif
#ifdef CONFIG_KSM
COW_KSM,
#endif
#ifdef CONFIG_ZSWAP
ZSWPIN,
ZSWPOUT,
ZSWPWB,
#endif
#ifdef CONFIG_X86
DIRECT_MAP_LEVEL2_SPLIT,
DIRECT_MAP_LEVEL3_SPLIT,
#endif
#ifdef CONFIG_PER_VMA_LOCK_STATS
VMA_LOCK_SUCCESS,
VMA_LOCK_ABORT,
VMA_LOCK_RETRY,
VMA_LOCK_MISS,
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
KSTACK_1K,
#if THREAD_SIZE > 1024
KSTACK_2K,
#endif
#if THREAD_SIZE > 2048
KSTACK_4K,
#endif
#if THREAD_SIZE > 4096
KSTACK_8K,
#endif
#if THREAD_SIZE > 8192
KSTACK_16K,
#endif
#if THREAD_SIZE > 16384
KSTACK_32K,
#endif
#if THREAD_SIZE > 32768
KSTACK_64K,
#endif
#if THREAD_SIZE > 65536
KSTACK_REST,
#endif
#endif /* CONFIG_DEBUG_STACK_USAGE */
NR_VM_EVENT_ITEMS
};
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
#define THP_FILE_ALLOC ({ BUILD_BUG(); 0; })
#define THP_FILE_FALLBACK ({ BUILD_BUG(); 0; })
#define THP_FILE_FALLBACK_CHARGE ({ BUILD_BUG(); 0; })
#define THP_FILE_MAPPED ({ BUILD_BUG(); 0; })
#endif
#endif /* VM_EVENT_ITEM_H_INCLUDED */