kernel_optimize_test/mm
Vlastimil Babka ea57485af8 mm, page_alloc: fix check for NULL preferred_zone
Patch series "fix premature OOM regression in 4.7+ due to cpuset races".

This is v2 of my attempt to fix the recent report based on LTP cpuset
stress test [1].  The intention is to go to stable 4.9 LTSS with this,
as triggering repeated OOMs is not nice.  That's why the patches try to
be not too intrusive.

Unfortunately why investigating I found that modifying the testcase to
use per-VMA policies instead of per-task policies will bring the OOM's
back, but that seems to be much older and harder to fix problem.  I have
posted a RFC [2] but I believe that fixing the recent regressions has a
higher priority.

Longer-term we might try to think how to fix the cpuset mess in a better
and less error prone way.  I was for example very surprised to learn,
that cpuset updates change not only task->mems_allowed, but also
nodemask of mempolicies.  Until now I expected the parameter to
alloc_pages_nodemask() to be stable.  I wonder why do we then treat
cpusets specially in get_page_from_freelist() and distinguish HARDWALL
etc, when there's unconditional intersection between mempolicy and
cpuset.  I would expect the nodemask adjustment for saving overhead in
g_p_f(), but that clearly doesn't happen in the current form.  So we
have both crazy complexity and overhead, AFAICS.

[1] https://lkml.kernel.org/r/CAFpQJXUq-JuEP=QPidy4p_=FN0rkH5Z-kfB4qBvsf6jMS87Edg@mail.gmail.com
[2] https://lkml.kernel.org/r/7c459f26-13a6-a817-e508-b65b903a8378@suse.cz

This patch (of 4):

Since commit c33d6c06f6 ("mm, page_alloc: avoid looking up the first
zone in a zonelist twice") we have a wrong check for NULL preferred_zone,
which can theoretically happen due to concurrent cpuset modification.  We
check the zoneref pointer which is never NULL and we should check the zone
pointer.  Also document this in first_zones_zonelist() comment per Michal
Hocko.

Fixes: c33d6c06f6 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice")
Link: http://lkml.kernel.org/r/20170120103843.24587-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Ganapatrao Kulkarni <gpkulkarni@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24 16:26:14 -08:00
..
kasan Power management material for v4.10-rc1 2016-12-13 10:41:53 -08:00
backing-dev.c writeback: track if we're sleeping on progress in balance_dirty_pages() 2016-11-08 08:28:55 -07:00
balloon_compaction.c mm: balloon: use general non-lru movable page feature 2016-07-26 16:19:19 -07:00
bootmem.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
cleancache.c
cma_debug.c
cma.c mm/cma.c: check the max limit for cma allocation 2016-11-11 08:12:37 -08:00
cma.h
compaction.c mm, compaction: allow compaction for GFP_NOFS requests 2016-12-14 16:04:07 -08:00
debug_page_ref.c
debug.c mm, debug: print raw struct page data in __dump_page() 2016-12-12 18:55:08 -08:00
dmapool.c
early_ioremap.c
fadvise.c mm: fadvise: avoid expensive remote LRU cache draining after FADV_DONTNEED 2016-12-20 09:48:46 -08:00
failslab.c
filemap.c dax: fix deadlock with DAX 4k holes 2017-01-10 18:31:54 -08:00
frame_vector.c mm: replace get_vaddr_frames() write/force parameters with gup_flags 2016-10-19 08:11:24 -07:00
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup.c mm: unexport __get_user_pages_unlocked() 2016-12-14 16:04:09 -08:00
highmem.c
huge_memory.c mm/huge_memory.c: respect FOLL_FORCE/FOLL_COW for thp 2017-01-24 16:26:14 -08:00
hugetlb_cgroup.c
hugetlb.c mm/hugetlb.c: fix reservation race when freeing surplus pages 2017-01-10 18:31:55 -08:00
hwpoison-inject.c
init-mm.c mm: Add a user_ns owner to mm_struct and fix ptrace permission checks 2016-11-22 11:49:48 -06:00
internal.h mm: add PageWaiters indicating tasks are waiting for a page bit 2016-12-25 11:54:48 -08:00
interval_tree.c
Kconfig mm: THP page cache support for ppc64 2016-12-12 18:55:08 -08:00
Kconfig.debug PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO 2016-09-13 02:35:27 +02:00
khugepaged.c mm: get rid of __GFP_OTHER_NODE 2017-01-10 18:31:55 -08:00
kmemcheck.c
kmemleak-test.c
kmemleak.c kmemleak: fix reference to Documentation 2016-12-12 18:55:07 -08:00
ksm.c mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node() 2016-10-07 18:46:29 -07:00
list_lru.c mm/list_lru.c: avoid error-path NULL pointer deref 2016-10-27 18:43:42 -07:00
maccess.c
madvise.c mm: add tlb_remove_check_page_size_change to track page size change 2016-12-12 18:55:07 -08:00
Makefile Disable the __builtin_return_address() warning globally after all 2016-10-12 10:23:41 -07:00
memblock.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
memcontrol.c mm, memcg: do not retry precharge charges 2017-01-24 16:26:14 -08:00
memory_hotplug.c memory_hotplug: make zone_can_shift() return a boolean value 2017-01-24 16:26:14 -08:00
memory-failure.c mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked 2016-12-25 11:54:48 -08:00
memory.c dax: wrprotect pmd_t in dax_mapping_entry_mkclean 2017-01-10 18:31:54 -08:00
mempolicy.c mm/mempolicy.c: do not put mempolicy before using its nodemask 2017-01-24 16:26:14 -08:00
mempool.c Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements" 2016-07-28 16:07:41 -07:00
memtest.c
migrate.c mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked 2016-12-25 11:54:48 -08:00
mincore.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mlock.c thp: fix corner case of munlock() of PTE-mapped THPs 2016-11-30 16:32:52 -08:00
mm_init.c
mmap.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mremap.c mremap: move_ptes: check pte dirty after its removal 2016-11-29 08:20:24 -08:00
msync.c
nobootmem.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
nommu.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
oom_kill.c oom: print nodemask in the oom report 2016-10-07 18:46:29 -07:00
page_alloc.c mm, page_alloc: fix check for NULL preferred_zone 2017-01-24 16:26:14 -08:00
page_counter.c
page_ext.c mm/page_ext: support extra space allocation by page_ext user 2016-10-07 18:46:27 -07:00
page_idle.c mm, vmscan: move lru_lock to the node 2016-07-28 16:07:41 -07:00
page_io.c writeback: add wbc_to_write_flags() 2016-11-02 10:24:03 -06:00
page_isolation.c mm/page_isolation: fix typo: "paes" -> "pages" 2016-10-07 18:46:29 -07:00
page_owner.c mm/page_owner: don't define fields on struct page_ext by hard-coding 2016-10-07 18:46:27 -07:00
page_poison.c mm: check the return value of lookup_page_ext for all call sites 2016-06-03 15:06:22 -07:00
page-writeback.c radix-tree: delete radix_tree_range_tag_if_tagged() 2016-12-14 16:04:10 -08:00
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2016-12-13 12:34:47 -08:00
pgtable-generic.c
process_vm_access.c mm: unexport __get_user_pages_unlocked() 2016-12-14 16:04:09 -08:00
quicklist.c
readahead.c mm: don't cap request size based on read-ahead setting 2016-12-12 18:55:08 -08:00
rmap.c mm, rmap: handle anon_vma_prepare() common case inline 2016-12-12 18:55:08 -08:00
shmem.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
slab_common.c mm/slab_common.c: check kmem_create_cache flags are common 2016-12-12 18:55:06 -08:00
slab.c mm/slab.c: fix SLAB freelist randomization duplicate entries 2017-01-10 18:31:55 -08:00
slab.h mm, slab: maintain total slab count instead of active count 2016-12-12 18:55:07 -08:00
slob.c slub: move synchronize_sched out of slab_mutex on shrink 2016-12-12 18:55:06 -08:00
slub.c mm/slub.c: trace free objects at KERN_INFO 2017-01-24 16:26:14 -08:00
sparse-vmemmap.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sparse.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
swap_cgroup.c
swap_state.c mm, swap: use offset of swap entry as key of swap cache 2016-10-07 18:46:28 -07:00
swap.c mm: add PageWaiters indicating tasks are waiting for a page bit 2016-12-25 11:54:48 -08:00
swapfile.c mm: support anonymous stable page 2017-01-10 18:31:55 -08:00
truncate.c mm: Invalidate DAX radix tree entries only if appropriate 2016-12-26 20:29:24 -08:00
usercopy.c mm: usercopy: Check for module addresses 2016-09-20 16:07:39 -07:00
userfaultfd.c
util.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
vmacache.c mm: unrig VMA cache hit ratio 2016-10-07 18:46:27 -07:00
vmalloc.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
vmpressure.c
vmscan.c mm, memcg: fix the active list aging for lowmem requests when memcg is enabled 2017-01-10 18:31:55 -08:00
vmstat.c mm/vmstat: Convert to hotplug state machine 2016-12-02 00:52:35 +01:00
workingset.c mm: workingset: fix use-after-free in shadow node shrinker 2017-01-07 18:22:40 -08:00
z3fold.c mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup 2016-06-03 16:02:55 -07:00
zbud.c
zpool.c
zsmalloc.c mm/zsmalloc: Convert to hotplug state machine 2016-12-02 00:52:36 +01:00
zswap.c mm/zswap: Convert pool to hotplug state machine 2016-12-02 00:52:36 +01:00