linux/mm
Li Zhijian 66eca1021a mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist()
It's expected that no page should be left in pcp_list after calling
zone_pcp_disable() in offline_pages().  Previously, it's observed that
offline_pages() gets stuck [1] due to some pages remaining in pcp_list.

Cause:
There is a race condition between drain_pages_zone() and __rmqueue_pcplist()
involving the pcp->count variable. See below scenario:

         CPU0                              CPU1
    ----------------                    ---------------
                                      spin_lock(&pcp->lock);
                                      __rmqueue_pcplist() {
zone_pcp_disable() {
                                        /* list is empty */
                                        if (list_empty(list)) {
                                          /* add pages to pcp_list */
                                          alloced = rmqueue_bulk()
  mutex_lock(&pcp_batch_high_lock)
  ...
  __drain_all_pages() {
    drain_pages_zone() {
      /* read pcp->count, it's 0 here */
      count = READ_ONCE(pcp->count)
      /* 0 means nothing to drain */
                                          /* update pcp->count */
                                          pcp->count += alloced << order;
      ...
                                      ...
                                      spin_unlock(&pcp->lock);

In this case, after calling zone_pcp_disable() though, there are still some
pages in pcp_list. And these pages in pcp_list are neither movable nor
isolated, offline_pages() gets stuck as a result.

Solution:
Expand the scope of the pcp->lock to also protect pcp->count in
drain_pages_zone(), to ensure no pages are left in the pcp list after
zone_pcp_disable()

[1] https://lore.kernel.org/linux-mm/6a07125f-e720-404c-b2f9-e55f3f166e85@fujitsu.com/

Link: https://lkml.kernel.org/r/20240723064428.1179519-1-lizhijian@fujitsu.com
Fixes: 4b23a68f95 ("mm/page_alloc: protect PCP lists with a spinlock")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reported-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-26 14:33:09 -07:00
..
damon mm: provide mm_struct and address to huge_ptep_get() 2024-07-12 15:52:15 -07:00
kasan
kfence mm: remove CONFIG_MEMCG_KMEM 2024-07-10 12:14:54 -07:00
kmsan kmsan: do not pass NULL pointers as 0 2024-07-03 19:30:26 -07:00
backing-dev.c
balloon_compaction.c mm: remove MIGRATE_SYNC_NO_COPY mode 2024-07-03 19:30:00 -07:00
bootmem_info.c
cma_debug.c
cma_sysfs.c
cma.c
cma.h
compaction.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
debug_page_alloc.c
debug_page_ref.c
debug_vm_pgtable.c
debug.c
dmapool_test.c mm/dmapool: add MODULE_DESCRIPTION() 2024-07-03 19:29:58 -07:00
dmapool.c
early_ioremap.c
execmem.c
fadvise.c
fail_page_alloc.c mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC 2024-07-17 21:05:18 -07:00
failslab.c mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB 2024-07-17 21:05:18 -07:00
filemap.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
folio-compat.c mm: remove page_mapping() 2024-07-03 19:29:59 -07:00
gup_test.c
gup_test.h
gup.c mm: remove CONFIG_ARCH_HAS_HUGEPD 2024-07-12 15:52:19 -07:00
highmem.c mm/highmem: make nr_free_highpages() return "unsigned long" 2024-07-03 19:30:06 -07:00
hmm.c mm: provide mm_struct and address to huge_ptep_get() 2024-07-12 15:52:15 -07:00
huge_memory.c mm/huge_memory: avoid PMD-size page cache if needed 2024-07-26 14:33:09 -07:00
hugetlb_cgroup.c mm/hugetlb_cgroup: switch to the new cftypes 2024-07-03 19:30:10 -07:00
hugetlb_vmemmap.c Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix 2024-07-06 11:44:41 -07:00
hugetlb_vmemmap.h
hugetlb.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
hwpoison-inject.c mm/hwpoison: add MODULE_DESCRIPTION() 2024-07-03 19:29:58 -07:00
init-mm.c
internal.h Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix 2024-07-06 11:44:41 -07:00
interval_tree.c
io-mapping.c
ioremap.c
Kconfig - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
Kconfig.debug
khugepaged.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
kmemleak.c mm/kmemleak: replace strncpy() with strscpy() 2024-07-17 21:05:18 -07:00
ksm.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
list_lru.c mm: remove CONFIG_MEMCG_KMEM 2024-07-10 12:14:54 -07:00
maccess.c
madvise.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
Makefile mm: memcg: put cgroup v1-specific code under a config option 2024-07-04 18:05:54 -07:00
mapping_dirty_helpers.c
memblock.c memblock: updates for 6.11-rc1 2024-07-18 14:48:11 -07:00
memcontrol-v1.c mm: memcg1: convert charge move flags to unsigned long long 2024-07-17 21:05:19 -07:00
memcontrol-v1.h mm: memcg: gather memcg1-specific fields initialization in memcg1_memcg_init() 2024-07-04 18:05:56 -07:00
memcontrol.c mm/page_counter: move calculating protection values to page_counter 2024-07-12 15:52:20 -07:00
memfd.c mm/gup: introduce memfd_pin_folios() for pinning memfd folios 2024-07-12 15:52:09 -07:00
memory_hotplug.c mm/page_alloc: put __free_pages_core() in __meminit section 2024-07-12 15:52:21 -07:00
memory-failure.c mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUND 2024-07-12 15:52:22 -07:00
memory-tiers.c memory tier: consolidate the initialization of memory tiers 2024-07-12 15:52:20 -07:00
memory.c mm: fix old/young bit handling in the faulting path 2024-07-26 14:33:09 -07:00
mempolicy.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
mempool.c
memremap.c
memtest.c
migrate_device.c mm: extend rmap flags arguments for folio_add_new_anon_rmap 2024-07-03 19:30:18 -07:00
migrate.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
mincore.c mm: provide mm_struct and address to huge_ptep_get() 2024-07-12 15:52:15 -07:00
mlock.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
mm_init.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
mm_slot.h
mmap_lock.c mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer 2024-07-03 19:30:26 -07:00
mmap.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c mm: introduce pmd|pte_needs_soft_dirty_wp helpers for softdirty write-protect 2024-07-03 19:30:07 -07:00
mremap.c mm: remove page_mkclean() 2024-07-03 19:30:17 -07:00
mseal.c
msync.c
nommu.c
oom_kill.c
page_alloc.c mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist() 2024-07-26 14:33:09 -07:00
page_counter.c mm/page_counter: move calculating protection values to page_counter 2024-07-12 15:52:20 -07:00
page_ext.c mm: report per-page metadata information 2024-07-03 19:30:09 -07:00
page_idle.c
page_io.c mm: ignore data-race in __swap_writepage 2024-07-17 21:05:18 -07:00
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c
page_vma_mapped.c
page-writeback.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
pagewalk.c mm: remove CONFIG_ARCH_HAS_HUGEPD 2024-07-12 15:52:19 -07:00
percpu-internal.h mm: remove CONFIG_MEMCG_KMEM 2024-07-10 12:14:54 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c mm: remove CONFIG_MEMCG_KMEM 2024-07-10 12:14:54 -07:00
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix 2024-07-06 11:44:41 -07:00
rmap.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
rodata_test.c
secretmem.c
shmem_quota.c
shmem.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
show_mem.c
shrinker_debug.c
shrinker.c
shuffle.c
shuffle.h
slab_common.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
slab.h - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
slub.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
sparse-vmemmap.c mm: report per-page metadata information 2024-07-03 19:30:09 -07:00
sparse.c mm/sparse: nr_pages won't be 0 2024-07-03 19:30:19 -07:00
swap_cgroup.c
swap_slots.c
swap_state.c mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() 2024-07-12 15:52:22 -07:00
swap.c mm/gup: clear the LRU flag of a page before adding to LRU batch 2024-07-17 21:08:54 -07:00
swap.h mm: swap: remove 'synchronous' argument to swap_read_folio() 2024-07-03 19:30:06 -07:00
swapfile.c mm: use folio_add_new_anon_rmap() if folio_test_anon(folio)==false 2024-07-03 19:30:18 -07:00
truncate.c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
usercopy.c
userfaultfd.c mm: provide mm_struct and address to huge_ptep_get() 2024-07-12 15:52:15 -07:00
util.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
vmalloc.c Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix 2024-07-06 11:44:41 -07:00
vmpressure.c
vmscan.c Random number generator updates for Linux 6.11-rc1. 2024-07-24 10:29:50 -07:00
vmstat.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
workingset.c cachestat: do not flush stats in recency check 2024-07-03 22:40:37 -07:00
z3fold.c
zbud.c
zpool.c
zsmalloc.c zsmalloc: rename class stat mutators 2024-07-12 15:52:13 -07:00
zswap.c mm/zswap: fix a white space issue 2024-07-17 21:08:55 -07:00