Henry Willard e991f7ded4 mm: limit boost_watermark on small zones ... commit 14f69140ff upstream. Commit 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs") adds a boost_watermark() function which increases the min watermark in a zone by at least pageblock_nr_pages or the number of pages in a page block. On Arm64, with 64K pages and 512M huge pages, this is 8192 pages or 512M. It does this regardless of the number of managed pages managed in the zone or the likelihood of success. This can put the zone immediately under water in terms of allocating pages from the zone, and can cause a small machine to fail immediately due to OoM. Unlike set_recommended_min_free_kbytes(), which substantially increases min_free_kbytes and is tied to THP, boost_watermark() can be called even if THP is not active. The problem is most likely to appear on architectures such as Arm64 where pageblock_nr_pages is very large. It is desirable to run the kdump capture kernel in as small a space as possible to avoid wasting memory. In some architectures, such as Arm64, there are restrictions on where the capture kernel can run, and therefore, the space available. A capture kernel running in 768M can fail due to OoM immediately after boost_watermark() sets the min in zone DMA32, where most of the memory is, to 512M. It fails even though there is over 500M of free memory. With boost_watermark() suppressed, the capture kernel can run successfully in 448M. This patch limits boost_watermark() to boosting a zone's min watermark only when there are enough pages that the boost will produce positive results. In this case that is estimated to be four times as many pages as pageblock_nr_pages. Mel said: : There is no harm in marking it stable. Clearly it does not happen very : often but it's not impossible. 32-bit x86 is a lot less common now : which would previously have been vulnerable to triggering this easily. : ppc64 has a larger base page size but typically only has one zone. : arm64 is likely the most vulnerable, particularly when CMA is : configured with a small movable zone. Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs") Signed-off-by: Henry Willard <henry.willard@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1588294148-6586-1-git-send-email-henry.willard@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-05-14 07:58:26 +02:00
..
kasan	mm: introduce compound_nr()	2019-09-24 15:54:08 -07:00
Kconfig	mm,thp: add read-only THP support for (non-shmem) FS	2019-09-24 15:54:11 -07:00
Kconfig.debug	mm, page_owner, debug_pagealloc: save and dump freeing stack trace	2019-09-24 15:54:08 -07:00
Makefile	mm: silence -Woverride-init/initializer-overrides	2019-09-24 15:54:10 -07:00
backing-dev.c	memcg: fix a crash in wb_workfn when a device disappears	2020-02-11 04:35:11 -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: fail if fixed declaration can't be honored	2019-07-16 19:23:21 -07:00
cma.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
cma_debug.c	mm/cma_debug.c: fix the break condition in cma_maxchunk_get()	2019-05-14 09:47:45 -07:00
compaction.c	mm, compaction: fix wrong pfn handling in __reset_isolation_pfn()	2019-10-14 15:04:01 -07:00
debug.c	mm/debug.c: always print flags in dump_page()	2020-03-05 16:43:51 +01:00
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
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: Fix boot hang with earlyprintk=efi,keep	2017-12-11 14:54:44 +01:00
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: drop mmap_sem before calling balance_dirty_pages() in write fault	2020-01-09 10:19:55 +01:00
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: allow FOLL_FORCE for get_user_pages_fast()	2020-03-05 16:43:51 +01:00
gup_benchmark.c	mm/gup: fix memory leak in __gup_benchmark_ioctl	2020-01-09 10:20:00 +01:00
highmem.c	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
hmm.c	pagewalk: separate function pointers from iterator data	2019-09-07 04:28:04 -03:00
huge_memory.c	mm: fix possible PMD dirty bit lost in set_pmd_migration_entry()	2020-03-12 13:00:19 +01:00
hugetlb.c	mm/hugetlb: fix a addressing exception caused by huge_pte_offset	2020-04-29 16:33:14 +02:00
hugetlb_cgroup.c	mm: hugetlb: switch to css_tryget() in hugetlb_cgroup_charge_cgroup()	2019-11-15 18:34:00 -08:00
hwpoison-inject.c	hwpoison-inject: no need to check return value of debugfs_create functions	2019-06-03 15:39:40 +02:00
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: drop mmap_sem before calling balance_dirty_pages() in write fault	2020-01-09 10:19:55 +01:00
interval_tree.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248	2019-06-19 17:09:08 +02:00
khugepaged.c	mm,thp: recheck each page before collapsing file THP	2019-11-15 18:34:00 -08:00
kmemleak-test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333	2019-06-05 17:37:06 +02:00
kmemleak.c	kmemleak: Do not corrupt the object_list during clean-up	2019-10-14 08:56:16 -07:00
ksm.c	mm/ksm: fix NULL pointer dereference when KSM zero page is enabled	2020-04-29 16:33:15 +02:00
list_lru.c	mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages	2019-07-12 11:05:44 -07:00
maccess.c	uaccess: Add non-pagefault user-space write function	2020-01-17 19:48:40 +01:00
madvise.c	mm: do not allow MADV_PAGEOUT for CoW pages	2020-03-25 08:25:57 +01:00
memblock.c	mm: memblock: do not enforce current limit for memblock_phys* family	2019-10-19 06:32:32 -04:00
memcontrol.c	mm, memcg: do not high throttle allocators based on wraparound	2020-04-17 10:50:17 +02:00
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: don't access uninitialized memmaps in memory_failure()	2019-10-19 06:32:31 -04:00
memory.c	mm: drop mmap_sem before calling balance_dirty_pages() in write fault	2020-01-09 10:19:55 +01:00
memory_hotplug.c	mm, hotplug: fix page online with DEBUG_PAGEALLOC compiled but not enabled	2020-03-12 13:00:19 +01:00
mempolicy.c	mm: mempolicy: require at least one nodeid for MPOL_PREFERRED	2020-04-08 09:08:47 +02:00
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: shrink zones when offlining memory	2020-01-09 10:19:56 +01:00
memtest.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
migrate.c	mm: move_pages: report the number of non-attempted pages	2020-02-11 04:35:13 -08:00
mincore.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
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()	2020-02-28 17:22:21 +01:00
mmu_context.c	sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
mmu_gather.c	mm/mmu_gather: invalidate TLB correctly on batch allocation failure and flush	2020-02-11 04:35:42 -08:00
mmu_notifier.c	mm/mmu_notifiers: use the right return code for WARN_ON	2019-11-06 08:47:50 -08:00
mmzone.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mprotect.c	mm, numa: fix bad pmd by atomically check for pmd_trans_huge when marking page tables prot_numa	2020-03-12 13:00:19 +01:00
mremap.c	mm/mremap: Add comment explaining the untagging behaviour of mremap()	2020-05-10 10:31:33 +02:00
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()	2020-03-25 08:25:58 +01:00
oom_kill.c	mm/oom: fix pgtables units mismatch in Killed process message	2020-01-09 10:19:57 +01:00
page-writeback.c	mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio()	2020-01-23 08:22:41 +01:00
page_alloc.c	mm: limit boost_watermark on small zones	2020-05-14 07:58:26 +02:00
page_counter.c	memcg: introduce memory.min	2018-06-07 17:34:36 -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	mm/page_io.c: do not free shared swap slots	2019-11-15 18:34:00 -08:00
page_isolation.c	mm/page_isolation.c: change the prototype of undo_isolate_page_range()	2019-07-12 11:05:43 -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_vma_mapped.c	mm: introduce page_size()	2019-09-24 15:54:08 -07:00
pagewalk.c	pagewalk: use lockdep_assert_held for locking validation	2019-09-07 04:28:04 -03:00
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	percpu: Use struct_size() helper	2019-09-04 13:40:49 -07:00
pgtable-generic.c	x86/mm: Page size aware flush_tlb_mm_range()	2018-10-09 16:51:11 +02:00
process_vm_access.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
readahead.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
rmap.c	mm: include <linux/huge_mm.h> for is_vma_temporary_stack	2019-10-19 06:32:32 -04:00
rodata_test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
shmem.c	mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path	2020-05-02 08:48:54 +02:00
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	2020-01-23 08:22:40 +01:00
slab.h	mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly	2019-11-06 08:47:50 -08:00
slab_common.c	mm: memcg/slab: call flush_memcg_workqueue() only if memcg workqueue is valid	2020-01-23 08:22:39 +01:00
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: improve bit diffusion for freelist ptr obfuscation	2020-04-13 10:48:07 +02:00
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	2020-04-01 11:02:03 +02:00
swap.c	mm: introduce MADV_COLD	2019-09-25 17:51:41 -07:00
swap_cgroup.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
swap_slots.c	mm, swap, get_swap_pages: use entry_size instead of cluster in parameter	2018-08-22 10:52:44 -07:00
swap_state.c	mm: page cache: store only head pages in i_pages	2019-09-24 15:54:08 -07:00
swapfile.c	mm/swapfile.c: move inode_lock out of claim_swapfile	2020-04-01 11:02:02 +02:00
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	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499	2019-06-19 17:09:53 +02:00
util.c	arm64, mm: make randomization selected by generic topdown mmap layout	2019-09-24 15:54:11 -07:00
vmacache.c	mm: get rid of vmacache_flush_all() entirely	2018-09-13 15:18:04 -10:00
vmalloc.c	vmalloc: fix remap_vmalloc_range() bounds checks	2020-04-29 16:33:14 +02:00
vmpressure.c	mm/vmpressure.c: fix a signedness bug in vmpressure_register_event()	2019-10-07 15:47:19 -07:00
vmscan.c	mm/vmscan.c: don't round up scan size for online memory cgroup	2020-02-28 17:22:20 +01:00
vmstat.c	mm, vmstat: reduce zone->lock holding time by /proc/pagetypeinfo	2019-11-06 08:47:50 -08:00
workingset.c	mm: workingset: fix vmstat counters for shadow nodes	2019-08-13 16:06:52 -07:00
z3fold.c	mm/z3fold.c: claim page in the beginning of free	2019-10-07 15:47:19 -07:00
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.	2020-01-09 10:19:56 +01:00
zswap.c	zswap: do not map same object twice	2019-09-24 15:54:12 -07:00