linux/mm
Shakeel Butt 013339df11 mm/rmap: always do TTU_IGNORE_ACCESS
Since commit 369ea8242c ("mm/rmap: update to new mmu_notifier semantic
v2"), the code to check the secondary MMU's page table access bit is
broken for !(TTU_IGNORE_ACCESS) because the page is unmapped from the
secondary MMU's page table before the check.  More specifically for those
secondary MMUs which unmap the memory in
mmu_notifier_invalidate_range_start() like kvm.

However memory reclaim is the only user of !(TTU_IGNORE_ACCESS) or the
absence of TTU_IGNORE_ACCESS and it explicitly performs the page table
access check before trying to unmap the page.  So, at worst the reclaim
will miss accesses in a very short window if we remove page table access
check in unmapping code.

There is an unintented consequence of !(TTU_IGNORE_ACCESS) for the memcg
reclaim.  From memcg reclaim the page_referenced() only account the
accesses from the processes which are in the same memcg of the target page
but the unmapping code is considering accesses from all the processes, so,
decreasing the effectiveness of memcg reclaim.

The simplest solution is to always assume TTU_IGNORE_ACCESS in unmapping
code.

Link: https://lkml.kernel.org/r/20201104231928.1494083-1-shakeelb@google.com
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:39 -08:00
..
kasan kasan: fix object remaining in offline per-cpu quarantine 2020-12-11 14:02:14 -08:00
backing-dev.c bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag 2020-09-24 13:43:39 -06:00
balloon_compaction.c
cleancache.c
cma_debug.c debugfs: make sure we can remove u32_array files cleanly 2020-07-10 13:54:00 -07:00
cma.c cma: don't quit at first error when activating reserved areas 2020-08-12 10:57:57 -07:00
cma.h mm: cma: use CMA_MAX_NAME to define the length of cma name array 2020-09-01 09:19:43 +02:00
compaction.c mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate 2020-11-14 11:26:03 -08:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: avoid doing memory allocation with pgtable_t mapped. 2020-10-16 11:11:14 -07:00
debug.c mm, dump_page: rename head_mapcount() --> head_compound_mapcount() 2020-10-13 18:38:29 -07:00
dmapool.c mm/dmapool.c: replace hard coded function name with __func__ 2020-10-13 18:38:32 -07:00
early_ioremap.c
fadvise.c mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED 2020-10-13 18:38:29 -07:00
failslab.c
filemap.c mm: memcontrol: add file_thp, shmem_thp to memory.stat 2020-12-15 12:13:39 -08:00
frame_vector.c
frontswap.c mm/frontswap: mark various intentional data races 2020-08-14 19:56:56 -07:00
gup_test.c mm/gup_test.c: mark gup_test_init as __init function 2020-12-15 12:13:38 -08:00
gup_test.h selftests/vm: gup_test: introduce the dump_pages() sub-test 2020-12-15 12:13:38 -08:00
gup.c mm/gup: combine put_compound_head() and unpin_user_page() 2020-12-15 12:13:39 -08:00
highmem.c mm/highmem.c: clean up endif comments 2020-10-16 11:11:18 -07:00
hmm.c mm: do page fault accounting in handle_mm_fault 2020-08-12 10:58:02 -07:00
huge_memory.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
hugetlb_cgroup.c hugetlb_cgroup: fix offline of hugetlb cgroup with reservations 2020-12-06 10:19:07 -08:00
hugetlb.c mm/hugetlb: clear compound_nr before freeing gigantic pages 2020-12-11 14:02:14 -08:00
hwpoison-inject.c mm,hwpoison-inject: don't pin for hwpoison_filter 2020-10-16 11:11:16 -07:00
init-mm.c mm/gup: prevent gup_fast from racing with COW during fork 2020-12-15 12:13:39 -08:00
internal.h mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
interval_tree.c
ioremap.c mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
Kconfig mm/gup_test: GUP_TEST depends on DEBUG_FS 2020-12-15 12:13:38 -08:00
Kconfig.debug treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
khugepaged.c mm: memcontrol: add file_thp, shmem_thp to memory.stat 2020-12-15 12:13:39 -08:00
kmemleak.c mm/kmemleak: rely on rcu for task stack scanning 2020-10-13 18:38:27 -07:00
ksm.c docs: get rid of :c:type explicit declarations for structs 2020-10-15 07:49:40 +02:00
list_lru.c mm: list_lru: set shrinker map bit when child nr_items is not zero 2020-12-06 10:19:07 -08:00
maccess.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
madvise.c mm/madvise: remove racy mm ownership check 2020-12-08 20:57:18 -08:00
Makefile mm/gup_benchmark: rename to mm/gup_test 2020-12-15 12:13:38 -08:00
mapping_dirty_helpers.c
memblock.c memblock: get rid of a :c:type leftover 2020-10-15 07:49:46 +02:00
memcontrol.c mm: memcg/slab: fix use after free in obj_cgroup_charge 2020-12-15 12:13:39 -08:00
memfd.c
memory_hotplug.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
memory-failure.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
memory.c mm/gup: prevent gup_fast from racing with COW during fork 2020-12-15 12:13:39 -08:00
mempolicy.c mm: mempolicy: fix potential pte_unmap_unlock pte error 2020-11-02 12:14:19 -08:00
mempool.c mm/mempool: add 'else' to split mutually exclusive case 2020-10-13 18:38:34 -07:00
memremap.c mm/mremap_pages: fix static key devmap_managed_key updates 2020-11-02 12:14:18 -08:00
memtest.c
migrate.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
mincore.c mm: factor find_get_incore_page out of mincore_page 2020-10-13 18:38:29 -07:00
mlock.c mlock: fix unevictable_pgs event counts on THP 2020-09-19 13:13:38 -07:00
mm_init.c mm: adjust vm_committed_as_batch according to vm overcommit policy 2020-08-07 11:33:26 -07:00
mmap.c mm/mmap.c: fix mmap return value when vma is merged after call_mmap() 2020-12-06 10:19:07 -08:00
mmu_gather.c
mmu_notifier.c mm/mmu_notifier: fix mmget() assert in __mmu_interval_notifier_insert 2020-10-16 11:11:17 -07:00
mmzone.c
mprotect.c mm: Introduce arch_validate_flags() 2020-09-04 12:46:07 +01:00
mremap.c mm/mremap: start addresses are properly aligned 2020-08-07 11:33:27 -07:00
msync.c
nommu.c mm: remove alloc_vm_area 2020-10-18 09:27:10 -07:00
oom_kill.c mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary 2020-10-13 18:38:35 -07:00
page_alloc.c page_frag: Recover from memory pressure 2020-11-18 15:21:56 -08:00
page_counter.c mm/page_counter: correct the obsolete func name in the comment of page_counter_try_charge() 2020-10-13 18:38:30 -07:00
page_ext.c mm: fix page_owner initializing issue for arm32 2020-12-15 12:13:38 -08:00
page_idle.c
page_io.c mm/page_io.c: remove useless out label in __swap_writepage() 2020-10-13 18:38:30 -07:00
page_isolation.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
page_owner.c mm/page_owner: record timestamp and pid 2020-12-15 12:13:38 -08:00
page_poison.c mm/page_poison.c: replace bool variable with static key 2020-10-16 11:11:17 -07:00
page_reporting.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
page_reporting.h
page_vma_mapped.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
page-writeback.c mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback) 2020-11-24 15:23:19 -08:00
pagewalk.c
percpu-internal.h mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-km.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-stats.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-vm.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu.c percpu: convert flexible array initializers to use struct_size() 2020-10-30 23:02:28 +00:00
pgalloc-track.h mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
pgtable-generic.c
process_vm_access.c mm/process_vm_access: Add missing #include <linux/compat.h> 2020-10-27 12:41:29 -07:00
ptdump.c
readahead.c mm: use limited read-ahead to satisfy read 2020-10-17 13:49:08 -06:00
rmap.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
shmem.c mm: memcontrol: add file_thp, shmem_thp to memory.stat 2020-12-15 12:13:39 -08:00
shuffle.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
shuffle.h mm/shuffle: remove dynamic reconfiguration 2020-08-07 11:33:29 -07:00
slab_common.c mm: slab: clarify krealloc()'s behavior with __GFP_ZERO 2020-12-15 12:13:37 -08:00
slab.c mm/slab: rerform init_on_free earlier 2020-12-15 12:13:37 -08:00
slab.h mm: memcontrol: remove unused mod_memcg_obj_state() 2020-12-15 12:13:39 -08:00
slob.c mm: memcg: convert vmstat slab counters to bytes 2020-08-07 11:33:24 -07:00
slub.c mm/slub: let number of online CPUs determine the slub page order 2020-12-15 12:13:38 -08:00
sparse-vmemmap.c mm/sparse: only sub-section aligned range would be populated 2020-08-07 11:33:27 -07:00
sparse.c mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG 2020-10-16 11:11:18 -07:00
swap_cgroup.c
swap_slots.c mm/swap_slots.c: remove always zero and unused return value of enable_swap_slots_cache() 2020-10-13 18:38:30 -07:00
swap_state.c mm/swap_state: skip meaningless swap cache readahead when ra_info.win == 0 2020-12-15 12:13:39 -08:00
swap.c mm: remove pagevec_lookup_range_nr_tag() 2020-12-15 12:13:39 -08:00
swapfile.c mm/swapfile.c: use memset to fill the swap_map with SWAP_HAS_CACHE 2020-12-15 12:13:39 -08:00
truncate.c mm/truncate: add parameter explanation for invalidate_mapping_pagevec 2020-12-15 12:13:38 -08:00
usercopy.c mm/usercopy.c: delete duplicated word 2020-08-12 10:57:58 -07:00
userfaultfd.c mm/vmscan: protect the workingset on anonymous LRU 2020-08-12 10:57:55 -07:00
util.c mm/util.c: update the kerneldoc for kstrdup_const() 2020-10-16 11:11:17 -07:00
vmacache.c kernel: better document the use_mm/unuse_mm API contract 2020-06-10 19:14:18 -07:00
vmalloc.c mm: remove the filename in the top of file comment in vmalloc.c 2020-10-18 09:27:10 -07:00
vmpressure.c
vmscan.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-15 12:13:39 -08:00
vmstat.c mm/vmstat.c: use helper macro abs() 2020-10-16 11:11:17 -07:00
workingset.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
z3fold.c mm/z3fold.c: use xx_zalloc instead xx_alloc and memset 2020-10-13 18:38:34 -07:00
zbud.c mm/zbud: remove redundant initialization 2020-10-13 18:38:34 -07:00
zpool.c mm/zpool.c: delete duplicated word and fix grammar 2020-08-12 10:57:58 -07:00
zsmalloc.c mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING 2020-12-06 10:19:07 -08:00
zswap.c