linux/mm
Jakub Kicinski 9b8b17541f mm, memcg: do not high throttle allocators based on wraparound
If a cgroup violates its memory.high constraints, we may end up unduly
penalising it.  For example, for the following hierarchy:

  A:   max high, 20 usage
  A/B: 9 high, 10 usage
  A/C: max high, 10 usage

We would end up doing the following calculation below when calculating
high delay for A/B:

  A/B: 10 - 9 = 1...
  A:   20 - PAGE_COUNTER_MAX = 21, so set max_overage to 21.

This gets worse with higher disparities in usage in the parent.

I have no idea how this disappeared from the final version of the patch,
but it is certainly Not Good(tm).  This wasn't obvious in testing because,
for a simple cgroup hierarchy with only one child, the result is usually
roughly the same.  It's only in more complex hierarchies that things go
really awry (although still, the effects are limited to a maximum of 2
seconds in schedule_timeout_killable at a maximum).

[chris@chrisdown.name: changelog]
Fixes: e26733e0d0 ("mm, memcg: throttle allocators based on ancestral memory.high")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[5.4.x]
Link: http://lkml.kernel.org/r/20200331152424.GA1019937@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-10 15:36:20 -07:00
..
kasan kasan: unset panic_on_warn before calling panic() 2020-04-07 10:43:44 -07:00
backing-dev.c memcg: fix a crash in wb_workfn when a device disappears 2020-01-31 10:30:36 -08:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma_debug.c mm/cma_debug.c: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
cma.c mm/cma.c: switch to bitmap_zalloc() for cma bitmap allocation 2019-12-01 12:59:09 -08:00
cma.h
compaction.c mm/compaction: add missing annotation for compact_lock_irqsave 2020-04-07 10:43:41 -07:00
debug_page_ref.c
debug.c mm: dump_page(): additional diagnostics for huge pinned pages 2020-04-02 09:35:27 -07:00
dmapool.c mm/dmapool.c: micro-optimisation remove unnecessary branch 2020-04-07 10:43:42 -07:00
early_ioremap.c mm/early_ioremap.c: use %pa to print resource_size_t variables 2020-01-31 10:30:38 -08:00
fadvise.c fs: Export generic_fadvise() 2019-08-30 22:43:58 -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: huge tmpfs: try to split_huge_page() when punching hole 2020-04-07 10:43:41 -07:00
frame_vector.c mm: untag user pointers in get_vaddr_frames 2019-09-25 17:51:41 -07:00
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup_benchmark.c mm/gup_benchmark: support pin_user_pages() and related calls 2020-04-02 09:35:27 -07:00
gup.c mm/gup: Let __get_user_pages_locked() return -EINTR for fatal signal 2020-04-08 09:05:58 -07:00
highmem.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
hmm.c mm/hmm: return error for non-vma snapshots 2020-03-30 16:58:36 -03:00
huge_memory.c userfaultfd: wp: support swap and page migration 2020-04-07 10:43:39 -07:00
hugetlb_cgroup.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
hugetlb.c mm/hugetlb: add missing annotation for gather_surplus_pages() 2020-04-07 10:43:41 -07:00
hwpoison-inject.c mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
init-mm.c mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch 2019-10-19 06:32:32 -04:00
internal.h mm: add function __putback_isolated_page 2020-04-07 10:43:38 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig libnvdimm for 5.7 2020-04-08 21:03:40 -07:00
Kconfig.debug mm: add generic ptdump 2020-02-04 03:05:25 +00:00
khugepaged.c khugepaged: skip collapse if uffd-wp detected 2020-04-07 10:43:39 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak.c: use address-of operator on section symbols 2020-04-02 09:35:26 -07:00
ksm.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
list_lru.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
maccess.c uaccess: Add strict non-pagefault kernel-space read function 2019-11-02 12:39:12 -07:00
madvise.c mm: do not allow MADV_PAGEOUT for CoW pages 2020-03-21 18:56:06 -07:00
Makefile mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: update huge page-table entry callbacks 2020-04-02 09:35:29 -07:00
memblock.c mm/memblock.c: remove redundant assignment to variable max_addr 2020-04-02 09:35:32 -07:00
memcontrol.c mm, memcg: do not high throttle allocators based on wraparound 2020-04-10 15:36:20 -07:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory_hotplug.c mm/memory_hotplug.c: use __pfn_to_section() instead of open-coding 2020-04-07 10:43:41 -07:00
memory-failure.c mm: code cleanup for MADV_FREE 2020-04-07 10:43:38 -07:00
memory.c mm: fix ambiguous comments for better code readability 2020-04-07 10:43:41 -07:00
mempolicy.c libnvdimm for 5.7 2020-04-08 21:03:40 -07:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memremap.c libnvdimm for 5.7 2020-04-08 21:03:40 -07:00
memtest.c
migrate.c userfaultfd: wp: support swap and page migration 2020-04-07 10:43:39 -07:00
mincore.c mm: pagewalk: add 'depth' parameter to pte_hole 2020-02-04 03:05:25 +00:00
mlock.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
mm_init.c mm/mm_init.c: clean code. Use BUILD_BUG_ON when comparing compile time constant 2020-04-07 10:43:41 -07:00
mmap.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
mmu_context.c
mmu_gather.c asm-generic/tlb: provide MMU_GATHER_TABLE_FREE 2020-02-04 03:05:26 +00:00
mmu_notifier.c mm/mmu_notifier: silence PROVE_RCU_LIST warnings 2020-03-21 18:56:06 -07:00
mmzone.c
mprotect.c userfaultfd: wp: support swap and page migration 2020-04-07 10:43:39 -07:00
mremap.c mm/mremap: add MREMAP_DONTUNMAP to mremap() 2020-04-02 09:35:30 -07:00
msync.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
nommu.c x86/mm: split vmalloc_sync_all() 2020-03-21 18:56:06 -07:00
oom_kill.c mm, oom: dump stack of victim when reaping failed 2020-01-31 10:30:38 -08:00
page_alloc.c mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
page_counter.c mm, memcg: prevent memory.min load/store tearing 2020-04-02 09:35:29 -07:00
page_ext.c mm/page_ext.c: drop pfn_present() check when onlining 2020-04-07 10:43:40 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c fs: Enable bmap() function to properly return errors 2020-02-03 08:05:37 -05:00
page_isolation.c mm: add function __putback_isolated_page 2020-04-07 10:43:38 -07:00
page_owner.c mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo 2019-10-19 06:32:31 -04:00
page_poison.c mm/page_poison.c: fix a typo in a comment 2019-09-24 15:54:08 -07:00
page_reporting.c mm/page_reporting: add budget limit on how many pages can be reported per pass 2020-04-07 10:43:39 -07:00
page_reporting.h mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
page_vma_mapped.c mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page 2020-01-31 10:30:38 -08:00
page-writeback.c mm/gup/writeback: add callbacks for inaccessible pages 2020-04-02 09:35:27 -07:00
pagewalk.c x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c percpu: update copyright emails to dennis@kernel.org 2020-04-01 10:09:12 -07:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c percpu: update copyright emails to dennis@kernel.org 2020-04-01 10:09:12 -07:00
pgtable-generic.c asm-generic/mm: stub out p{4,u}d_clear_bad() if __PAGETABLE_P{4,U}D_FOLDED 2019-12-01 06:29:19 -08:00
process_vm_access.c mm: docs: Fix a comment in process_vm_rw_core 2020-03-25 10:04:01 -05:00
ptdump.c x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
readahead.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
rmap.c mm: prevent a warning when casting void* -> enum 2020-04-07 10:43:41 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
shuffle.c mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
shuffle.h mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
slab_common.c proc: faster open/read/close with "permanent" files 2020-04-07 10:43:42 -07:00
slab.c mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
slab.h mm: kmem: rename (__)memcg_kmem_(un)charge_memcg() to __memcg_kmem_(un)charge() 2020-04-02 09:35:28 -07:00
slob.c mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) 2019-10-07 15:47:20 -07:00
slub.c mm/slub: add missing annotation for put_map() 2020-04-07 10:43:41 -07:00
sparse-vmemmap.c mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap() 2019-07-18 17:08:07 -07:00
sparse.c mm/sparse.c: move subsection_map related functions together 2020-04-07 10:43:40 -07:00
swap_cgroup.c
swap_slots.c mm/swap_slots.c: assign|reset cache slot by value directly 2020-04-02 09:35:27 -07:00
swap_state.c mm/swap_state.c: use the same way to count page in [add_to|delete_from]_swap_cache 2020-04-02 09:35:28 -07:00
swap.c mm: huge tmpfs: try to split_huge_page() when punching hole 2020-04-07 10:43:41 -07:00
swapfile.c proc: faster open/read/close with "permanent" files 2020-04-07 10:43:42 -07:00
truncate.c mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
usercopy.c usercopy: Avoid HIGHMEM pfn warning 2019-09-17 15:20:17 -07:00
userfaultfd.c userfaultfd: wp: support write protection for userfault vma range 2020-04-07 10:43:39 -07:00
util.c mm/mmap.c: rb_parent is not necessary in __vma_link_list() 2019-12-01 06:29:19 -08:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c mm/vmalloc: fix a typo in comment 2020-04-07 10:43:38 -07:00
vmpressure.c mm: vmpressure: use mem_cgroup_is_root API 2020-04-02 09:35:31 -07:00
vmscan.c mm: code cleanup for MADV_FREE 2020-04-07 10:43:38 -07:00
vmstat.c mm, thp: track fallbacks due to failed memcg charges separately 2020-04-07 10:43:38 -07:00
workingset.c mm: vmscan: detect file thrashing at the reclaim root 2019-12-01 12:59:07 -08:00
z3fold.c mm/z3fold.c: do not include rwlock.h directly 2020-03-06 07:06:09 -06:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c zpool: add malloc_support_movable to zpool_driver 2019-09-24 15:54:12 -07:00
zsmalloc.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
zswap.c mm/zswap: allow setting default status, compressor and allocator in Kconfig 2020-04-07 10:43:41 -07:00