linux-stable/mm
Zheng Yejian fbab853231 mm/damon/vaddr: fix issue in damon_va_evenly_split_region()
commit f3c7a1ede4 upstream.

Patch series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()".  v2.

According to the logic of damon_va_evenly_split_region(), currently
following split case would not meet the expectation:

  Suppose DAMON_MIN_REGION=0x1000,
  Case: Split [0x0, 0x3000) into 2 pieces, then the result would be
        acutually 3 regions:
          [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000)
        but NOT the expected 2 regions:
          [0x0, 0x1000), [0x1000, 0x3000) !!!

The root cause is that when calculating size of each split piece in
damon_va_evenly_split_region():

  `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);`

both the dividing and the ALIGN_DOWN may cause loss of precision, then
each time split one piece of size 'sz_piece' from origin 'start' to 'end'
would cause more pieces are split out than expected!!!

To fix it, count for each piece split and make sure no more than
'nr_pieces'.  In addition, add above case into damon_test_split_evenly().

And add 'nr_piece == 1' check in damon_va_evenly_split_region() for better
code readability and add a corresponding kunit testcase.


This patch (of 2):

According to the logic of damon_va_evenly_split_region(), currently
following split case would not meet the expectation:

  Suppose DAMON_MIN_REGION=0x1000,
  Case: Split [0x0, 0x3000) into 2 pieces, then the result would be
        acutually 3 regions:
          [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000)
        but NOT the expected 2 regions:
          [0x0, 0x1000), [0x1000, 0x3000) !!!

The root cause is that when calculating size of each split piece in
damon_va_evenly_split_region():

  `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);`

both the dividing and the ALIGN_DOWN may cause loss of precision,
then each time split one piece of size 'sz_piece' from origin 'start' to
'end' would cause more pieces are split out than expected!!!

To fix it, count for each piece split and make sure no more than
'nr_pieces'. In addition, add above case into damon_test_split_evenly().

After this patch, damon-operations test passed:

 # ./tools/testing/kunit/kunit.py run damon-operations
 [...]
 ============== damon-operations (6 subtests) ===============
 [PASSED] damon_test_three_regions_in_vmas
 [PASSED] damon_test_apply_three_regions1
 [PASSED] damon_test_apply_three_regions2
 [PASSED] damon_test_apply_three_regions3
 [PASSED] damon_test_apply_three_regions4
 [PASSED] damon_test_split_evenly
 ================ [PASSED] damon-operations =================

Link: https://lkml.kernel.org/r/20241022083927.3592237-1-zhengyejian@huaweicloud.com
Link: https://lkml.kernel.org/r/20241022083927.3592237-2-zhengyejian@huaweicloud.com
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Fernand Sieber <sieberf@amazon.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Ye Weihua <yeweihua4@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14 19:51:45 +01:00
..
damon mm/damon/vaddr: fix issue in damon_va_evenly_split_region() 2024-12-14 19:51:45 +01:00
kasan kasan: disable kasan_non_canonical_hook() for HW tags 2023-12-23 10:42:00 +01:00
kfence mm: kfence: fix using kfence_metadata without initialization in show_object() 2023-03-30 12:48:01 +02:00
backing-dev.c writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs 2023-05-11 23:00:18 +09:00
balloon_compaction.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-31 17:16:48 +02:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma_debug.c mm/cma: change cma mutex to irq safe spinlock 2021-05-05 11:27:21 -07:00
cma_sysfs.c mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
cma.c mm/cma: drop incorrect alignment check in cma_init_reserved_mem 2024-07-05 09:14:13 +02:00
cma.h mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
compaction.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-10 16:19:37 +02:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug_vm_pgtable.c mm/debug_vm_pgtable: remove pte entry from the page table 2022-02-08 18:34:05 +01:00
debug.c mm/debug: sync up latest migrate_reason to migrate_reason_names 2021-09-24 16:13:35 -07:00
dmapool.c mm/dmapool: use DEVICE_ATTR_RO macro 2021-06-29 10:53:52 -07:00
early_ioremap.c mm/early_ioremap.c: remove redundant early_ioremap_shutdown() 2021-09-08 11:50:24 -07:00
fadvise.c mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED 2020-10-13 18:38:29 -07:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap: avoid buffered read/write race to read inconsistent data 2024-01-05 15:13:39 +01:00
frontswap.c mm/mempool: minor coding style tweaks 2021-05-05 11:27:27 -07:00
gup_test.c selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages 2021-05-05 11:27:26 -07:00
gup_test.h selftests/vm: gup_test: fix test flag 2021-05-05 11:27:26 -07:00
gup.c mm/migration: return errno when isolate_huge_page failed 2023-02-14 19:17:56 +01:00
highmem.c highmem: fix checks in __kmap_local_sched_{in,out} 2022-04-13 20:59:21 +02:00
hmm.c mm/hmm: fault non-owner device private entries 2022-08-03 12:03:54 +02:00
huge_memory.c mm/numa: no task_numa_fault() call if PMD is changed 2024-09-04 13:23:36 +02:00
hugetlb_cgroup.c hugetlb: make free_huge_page irq safe 2021-05-05 11:27:22 -07:00
hugetlb_vmemmap.c mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON 2021-06-30 20:47:26 -07:00
hugetlb_vmemmap.h mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate 2021-06-30 20:47:25 -07:00
hugetlb.c mm/hugetlb: fix possible recursive locking detected warning 2024-08-19 05:45:10 +02:00
hwpoison-inject.c mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler 2022-07-12 16:35:05 +02:00
init-mm.c mm: add setup_initial_init_mm() helper 2021-07-08 11:48:21 -07:00
internal.h mm: unconditionally close VMAs on error 2024-12-14 19:50:38 +01:00
interval_tree.c mm/interval_tree: add comments to improve code readability 2021-04-30 11:20:38 -07:00
io-mapping.c mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
ioremap.c mm: move ioremap_page_range to vmalloc.c 2021-09-08 11:50:24 -07:00
Kconfig kmap_local: don't assume kmap PTEs are linear arrays in memory 2021-11-25 09:48:43 +01:00
Kconfig.debug mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO 2020-12-15 12:13:46 -08:00
khugepaged.c mm/khugepaged: check again on anon uffd-wp during isolation 2023-04-26 13:51:52 +02:00
kmemleak.c Revert "mm: kmemleak: take a full lowmem check in kmemleak_*_phys()" 2022-09-15 11:30:00 +02:00
ksm.c mm/ksm: remove old GCC 4.9+ check 2021-09-13 10:18:28 -07:00
list_lru.c mm: vmscan: consolidate shrinker_maps handling code 2021-05-05 11:27:23 -07:00
maccess.c maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault() 2022-11-26 09:24:47 +01:00
madvise.c mm: fix madivse_pageout mishandling on non-LRU page 2022-10-05 10:39:39 +02:00
Makefile mm: introduce Data Access MONitor (DAMON) 2021-09-08 11:50:24 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: remove double Note in kerneldoc 2021-07-01 11:06:02 -07:00
memblock.c memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
memcontrol.c memcg: protect concurrent access to mem_cgroup_idr 2024-09-12 11:07:53 +02:00
memfd.c memfd: check for non-NULL file_seals in memfd_create() syscall 2023-06-28 10:29:45 +02:00
memory_hotplug.c memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
memory-failure.c mm/huge_memory: don't unpoison huge_zero_folio 2024-07-05 09:14:22 +02:00
memory.c mm/memory: add non-anonymous page check in the copy_present_page() 2024-11-17 15:06:26 +01:00
mempolicy.c mm/numa_balancing: teach mpol_to_str about the balancing mode 2024-08-19 05:45:17 +02:00
mempool.c kasan: use separate (un)poison implementation for integrated init 2021-06-04 19:32:21 +01:00
memremap.c mm/memremap.c: map FS_DAX device memory as decrypted 2022-11-16 09:58:27 +01:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-04-10 16:18:42 +02:00
migrate.c mm/migrate: set swap entry values of THP tail pages properly. 2024-04-10 16:19:31 +02:00
mincore.c inode: make init and permission helpers idmapped mount aware 2021-01-24 14:27:16 +01:00
mlock.c mm/mlock: fix potential imbalanced rlimit ucounts adjustment 2022-05-15 20:18:53 +02:00
mm_init.c include/linux/page-flags-layout.h: cleanups 2021-04-30 11:20:42 -07:00
mmap_lock.c mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer 2024-08-19 05:45:10 +02:00
mmap.c mm: resolve faulty mmap_region() error path behaviour 2024-12-14 19:50:38 +01:00
mmu_gather.c mm/khugepaged: fix GUP-fast interaction by sending IPI 2022-12-14 11:37:17 +01:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-27 14:38:58 +02:00
mmzone.c mm/lru: replace pgdat lru_lock with lruvec lock 2020-12-15 14:48:04 -08:00
mprotect.c mm: don't try to NUMA-migrate COW pages that have other uses 2022-02-23 12:03:03 +01:00
mremap.c mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) 2022-04-13 20:59:22 +02:00
msync.c mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start 2021-04-30 11:20:37 -07:00
nommu.c mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling 2024-12-14 19:50:38 +01:00
oom_kill.c oom_kill.c: futex: delay the OOM reaper to allow time for proper futex cleanup 2022-04-27 14:38:58 +02:00
page_alloc.c mm: fix NULL pointer dereference in alloc_pages_bulk_noprof 2024-12-14 19:50:35 +01:00
page_counter.c mm: page_counter: mitigate consequences of a page_counter underflow 2021-04-30 11:20:38 -07:00
page_ext.c mm/migrate: add CPU hotplug to demotion #ifdef 2021-10-18 20:22:02 -10:00
page_idle.c mm/idle_page_tracking: make PG_idle reusable 2021-09-08 11:50:24 -07:00
page_io.c mm: fix unexpected zeroed page mapping with zram swap 2022-04-20 09:34:18 +02:00
page_isolation.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
page_owner.c mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE 2021-09-08 11:50:22 -07:00
page_poison.c mm: page_poison: print page info when corruption is caught 2021-04-30 11:20:36 -07:00
page_reporting.c mm/page_reporting: allow driver to specify reporting order 2021-06-29 10:53:47 -07:00
page_reporting.h mm/page_reporting: export reporting order as module parameter 2021-06-29 10:53:47 -07:00
page_vma_mapped.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
page-writeback.c Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" 2024-07-18 13:07:33 +02:00
pagewalk.c mm: pagewalk: Fix race between unmap and page walker 2022-09-08 12:28:05 +02:00
percpu-internal.h Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2021-07-01 17:17:24 -07:00
percpu-km.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu-stats.c percpu: rework memcg accounting 2021-06-05 20:43:15 +00:00
percpu-vm.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
pgalloc-track.h mm: fix typos in comments 2021-05-07 00:26:35 -07:00
pgtable-generic.c mm/thp: fix __split_huge_pmd_locked() on shmem migration entry 2021-06-16 09:24:42 -07:00
process_vm_access.c mm/process_vm_access.c: remove duplicate include 2021-05-05 11:27:27 -07:00
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-08 12:28:05 +02:00
readahead.c vfs: fix readahead(2) on block devices 2023-11-20 11:08:13 +01:00
rmap.c mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse 2022-09-05 10:30:07 +02:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
secretmem.c secretmem: disable memfd_secret() if arch cannot set direct map 2024-10-22 15:40:41 +02:00
shmem.c mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling 2024-12-14 19:50:38 +01:00
shuffle.c mm: eliminate "expecting prototype" kernel-doc warnings 2021-04-16 16:10:36 -07:00
shuffle.h mm/shuffle: fix section mismatch warning 2021-05-22 15:09:07 -10:00
slab_common.c mm: krealloc: Fix MTE false alarm in __do_krealloc 2024-11-17 15:06:26 +01:00
slab.c mm/slab: Fix undefined init_cache_node_node() for NUMA and !SMP 2023-03-30 12:47:56 +02:00
slab.h mm, kfence: support kmem_dump_obj() for KFENCE objects 2022-04-27 14:38:51 +02:00
slob.c mm, kfence: support kmem_dump_obj() for KFENCE objects 2022-04-27 14:38:51 +02:00
slub.c mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. 2022-09-28 11:11:44 +02:00
sparse-vmemmap.c mm: sparsemem: split the huge PMD mapping of vmemmap pages 2021-06-30 20:47:26 -07:00
sparse.c mm/sparsemem: fix race in accessing memory_section->usage 2024-02-23 08:54:34 +01:00
swap_cgroup.c mm: memcontrol: make swap tracking an integral part of memory control 2020-06-03 20:09:48 -07:00
swap_slots.c mm: Replace deprecated CPU-hotplug functions. 2021-08-28 01:46:17 +02:00
swap_state.c mm: swap: get rid of livelock in swapin readahead 2022-03-23 09:16:41 +01:00
swap.c mm: fs: invalidate bh_lrus for only cold path 2021-09-24 16:13:35 -07:00
swapfile.c mm/swapfile: skip HugeTLB pages for unuse_vma 2024-10-22 15:40:41 +02:00
truncate.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
usercopy.c mm/usercopy: return 1 from hardened_usercopy __setup() handler 2022-04-08 14:24:14 +02:00
userfaultfd.c userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb 2024-03-01 13:21:43 +01:00
util.c mm: unconditionally close VMAs on error 2024-12-14 19:50:38 +01:00
vmacache.c kernel: better document the use_mm/unuse_mm API contract 2020-06-10 19:14:18 -07:00
vmalloc.c mm/vmalloc: add a safer version of find_vm_area() for debug 2023-09-19 12:22:50 +02:00
vmpressure.c net-memcg: Fix scope of sockmem pressure indicators 2023-09-19 12:22:33 +02:00
vmscan.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-10 16:19:37 +02:00
vmstat.c vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event 2024-12-14 19:50:33 +01:00
workingset.c memcg: sync flush only if periodic flush is delayed 2022-04-27 14:38:57 +02:00
z3fold.c mm/z3fold: add kerneldoc fields for z3fold_pool 2021-07-01 11:06:03 -07:00
zbud.c mm/zbud: add kerneldoc fields for zbud_pool 2021-07-01 11:06:03 -07:00
zpool.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
zsmalloc.c zsmalloc: fix races between asynchronous zspage free and page migration 2022-06-06 08:43:39 +02:00
zswap.c mm/zswap.c: fix two bugs in zswap_writeback_entry() 2021-06-30 20:47:31 -07:00