From 4741526b83c5d3a3d661d1896f9e7414c5730bcb Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 19 May 2016 17:14:44 -0700 Subject: [PATCH] mm, page_alloc: restore the original nodemask if the fast path allocation failed The page allocator fast path uses either the requested nodemask or cpuset_current_mems_allowed if cpusets are enabled. If the allocation context allows watermarks to be ignored then it can also ignore memory policies. However, on entering the allocator slowpath the nodemask may still be cpuset_current_mems_allowed and the policies are enforced. This patch resets the nodemask appropriately before entering the slowpath. Link: http://lkml.kernel.org/r/20160504143628.GU2858@techsingularity.net Signed-off-by: Vlastimil Babka Signed-off-by: Mel Gorman Cc: Jesper Dangaard Brouer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ecf663358b0d..5c469c1dfb8b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3636,6 +3636,12 @@ retry_cpuset: alloc_mask = memalloc_noio_flags(gfp_mask); ac.spread_dirty_pages = false; + /* + * Restore the original nodemask if it was potentially replaced with + * &cpuset_current_mems_allowed to optimize the fast-path attempt. + */ + if (cpusets_enabled()) + ac.nodemask = nodemask; page = __alloc_pages_slowpath(alloc_mask, order, &ac); no_zone: -- 2.20.1