mm, thp: do not cause memcg oom for thp
authorDavid Rientjes <rientjes@google.com>
Thu, 22 Mar 2018 23:17:45 +0000 (16:17 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 23 Mar 2018 00:07:02 +0000 (17:07 -0700)
commit9d3c3354bb85bab4d865fe95039443f09a4c8394
tree69d708ca86450e18715e9ebfb9ca539237b0c075
parent1c610d5f93c709df56787f50b3576704ac271826
mm, thp: do not cause memcg oom for thp

Commit 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and
madvised allocations") changed the page allocator to no longer detect
thp allocations based on __GFP_NORETRY.

It did not, however, modify the mem cgroup try_charge() path to avoid
oom kill for either khugepaged collapsing or thp faulting.  It is never
expected to oom kill a process to allocate a hugepage for thp; reclaim
is governed by the thp defrag mode and MADV_HUGEPAGE, but allocations
(and charging) should fallback instead of oom killing processes.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803191409420.124411@chino.kir.corp.google.com
Fixes: 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations")
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/huge_memory.c
mm/khugepaged.c