linux-stable/mm
Johannes Weiner bc50bcc6e0 mm: memcontrol: clean up and document effective low/min calculations
The effective protection of any given cgroup is a somewhat complicated
construct that depends on the ancestor's configuration, siblings'
configurations, as well as current memory utilization in all these groups.
It's done this way to satisfy hierarchical delegation requirements while
also making the configuration semantics flexible and expressive in complex
real life scenarios.

Unfortunately, all the rules and requirements are sparsely documented, and
the code is a little too clever in merging different scenarios into a
single min() expression.  This makes it hard to reason about the
implementation and avoid breaking semantics when making changes to it.

This patch documents each semantic rule individually and splits out the
handling of the overcommit case from the regular case.

Michal Koutný also points out that the points of equilibrium as described
in the existing example scenarios aren't actually accurate.  Delete these
examples for now to avoid confusion.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Link: http://lkml.kernel.org/r/20200227195606.46212-3-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:28 -07:00
..
kasan RISC-V Patches for the 5.6 Merge Window, Part 1 2020-01-31 11:23:29 -08:00
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.c mm/cma.c: switch to bitmap_zalloc() for cma bitmap allocation 2019-12-01 12:59:09 -08:00
cma.h
cma_debug.c mm/cma_debug.c: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
compaction.c mm, compaction: fix wrong pfn handling in __reset_isolation_pfn() 2019-10-14 15:04:01 -07:00
debug.c mm: dump_page(): additional diagnostics for huge pinned pages 2020-04-02 09:35:27 -07:00
debug_page_ref.c
dmapool.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -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/filemap.c: rewrite pagecache_get_page documentation 2020-04-02 09:35:27 -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.c mm/gup: fix omission of check on FOLL_LONGTERM in gup fast path 2020-04-02 09:35:27 -07:00
gup_benchmark.c mm/gup_benchmark: support pin_user_pages() and related calls 2020-04-02 09:35:27 -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: pagewalk: add 'depth' parameter to pte_hole 2020-02-04 03:05:25 +00:00
huge_memory.c mm/gup: track FOLL_PIN pages 2020-04-02 09:35:27 -07:00
hugetlb.c mm/gup: page->hpage_pinned_refcount: exact pin counts for huge pages 2020-04-02 09:35:27 -07:00
hugetlb_cgroup.c hugetlb_cgroup: fix illegal access to memory 2020-03-29 09:47:05 -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: swap: make page_evictable() inline 2020-04-02 09:35:27 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig mm/Kconfig: fix trivial help text punctuation 2019-12-01 12:59:10 -08:00
Kconfig.debug mm: add generic ptdump 2020-02-04 03:05:25 +00:00
khugepaged.c mm/thp: flush file for !is_shmem PageDirty() case in collapse_file() 2019-12-01 12:59:09 -08:00
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 * PPC secure guest support 2019-12-04 11:08:30 -08:00
list_lru.c mm: memcg/slab: use mem_cgroup_from_obj() 2020-04-02 09:35:28 -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/Makefile: disable KCSAN for kmemleak 2020-04-02 09:35:26 -07:00
mapping_dirty_helpers.c mm: Add write-protect and clean utilities for address space ranges 2019-11-06 13:03:36 +01:00
memblock.c memblock: Use __func__ in remaining memblock_dbg() call sites 2020-01-31 10:30:38 -08:00
memcontrol.c mm: memcontrol: clean up and document effective low/min calculations 2020-04-02 09:35:28 -07:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory-failure.c mm/memory-failure.c: use page_shift() in add_to_kill() 2019-12-01 12:59:04 -08:00
memory.c mm: avoid data corruption on CoW fault into PFN-mapped VMA 2020-03-06 07:06:09 -06:00
memory_hotplug.c mm, hotplug: fix page online with DEBUG_PAGEALLOC compiled but not enabled 2020-03-06 07:06:09 -06:00
mempolicy.c mm/mempolicy.c: fix out of bounds write in mpol_parse_str() 2020-01-31 10:30:36 -08:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memremap.c mm/memory_hotplug: poison memmap in remove_pfn_range_from_zone() 2020-02-04 03:05:23 +00:00
memtest.c
migrate.c mm: pagewalk: add 'depth' parameter to pte_hole 2020-02-04 03:05:25 +00:00
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 treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmap.c mm: Avoid creating virtual address aliases in brk()/mmap()/mremap() 2020-02-20 10:03:14 +00:00
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 mm, numa: fix bad pmd by atomically check for pmd_trans_huge when marking page tables prot_numa 2020-03-06 07:06:09 -06:00
mremap.c mm/mremap: Add comment explaining the untagging behaviour of mremap() 2020-03-26 11:28:57 +00:00
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-writeback.c mm/gup/writeback: add callbacks for inaccessible pages 2020-04-02 09:35:27 -07:00
page_alloc.c mm: kmem: rename memcg_kmem_(un)charge() into memcg_kmem_(un)charge_page() 2020-04-02 09:35:28 -07:00
page_counter.c mm: memcontrol: fix memory.low proportional distribution 2020-04-02 09:35:28 -07:00
page_ext.c mm, page_owner: fix off-by-one error in __set_page_owner_handle() 2019-10-14 15:04:00 -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/page_isolation: fix potential warning from user 2020-01-31 10:30:39 -08:00
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_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
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 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c bitmap: genericize percpu bitmap region iterators 2020-01-20 16:40:56 +01:00
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, tree-wide: rename put_user_page*() to unpin_user_page*() 2020-01-31 10:30:38 -08:00
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/gup: page->hpage_pinned_refcount: exact pin counts for huge pages 2020-04-02 09:35:27 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c tmpfs: deny and force are not huge mount options 2020-02-18 15:07:30 -05:00
shuffle.c mm: fix -Wmissing-prototypes warnings 2019-10-07 15:47:19 -07:00
shuffle.h mm: maintain randomization of page free lists 2019-05-14 19:52:48 -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
slab_common.c mm, memcg: fix build error around the usage of kmem_caches 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 slub: relocate freelist pointer to middle of object 2020-04-02 09:35:26 -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: fix kernel crash with pfn_section_valid check 2020-03-29 09:47:06 -07:00
swap.c mm: swap: use smp_mb__after_atomic() to order LRU bit set 2020-04-02 09:35:28 -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
swapfile.c mm/swapfile: fix data races in try_to_unuse() 2020-04-02 09:35:27 -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 mm: fix typos in comments when calling __SetPageUptodate() 2019-12-01 12:59:10 -08:00
util.c mm/mmap.c: rb_parent is not necessary in __vma_link_list() 2019-12-01 06:29:19 -08:00
vmacache.c
vmalloc.c x86/mm: split vmalloc_sync_all() 2020-03-21 18:56:06 -07:00
vmpressure.c mm/vmpressure.c: fix a signedness bug in vmpressure_register_event() 2019-10-07 15:47:19 -07:00
vmscan.c mm: swap: make page_evictable() inline 2020-04-02 09:35:27 -07:00
vmstat.c mm/gup: /proc/vmstat: pin_user_pages (FOLL_PIN) reporting 2020-04-02 09:35:27 -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/zsmalloc.c: fix the migrated zspage statistics. 2020-01-04 13:55:09 -08:00
zswap.c zswap: potential NULL dereference on error in init_zswap() 2020-01-31 10:30:39 -08:00