From 9933a0c8a5396df6dbaef809a9ee4ad64ebc3abe Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Tue, 11 Aug 2020 18:37:20 -0700 Subject: mm/migrate: clear __GFP_RECLAIM to make the migration callback consistent with regular THP allocations new_page_nodemask is a migration callback and it tries to use a common gfp flags for the target page allocation whether it is a base page or a THP. The later only adds GFP_TRANSHUGE to the given mask. This results in the allocation being slightly more aggressive than necessary because the resulting gfp mask will contain also __GFP_RECLAIM_KSWAPD. THP allocations usually exclude this flag to reduce over eager background reclaim during a high THP allocation load which has been seen during large mmaps initialization. There is no indication that this is a problem for migration as well but theoretically the same might happen when migrating large mappings to a different node. Make the migration callback consistent with regular THP allocations. [akpm@linux-foundation.org: fix comment typo, per Vlastimil] Signed-off-by: Joonsoo Kim Signed-off-by: Andrew Morton Acked-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Christoph Hellwig Cc: Mike Kravetz Cc: Naoya Horiguchi Cc: Roman Gushchin Link: http://lkml.kernel.org/r/1594622517-20681-5-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds --- mm/migrate.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/migrate.c b/mm/migrate.c index 8d084e9bc13b..46cca5c2ebff 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1554,6 +1554,11 @@ struct page *new_page_nodemask(struct page *page, } if (PageTransHuge(page)) { + /* + * clear __GFP_RECLAIM to make the migration callback + * consistent with regular THP allocations. + */ + gfp_mask &= ~__GFP_RECLAIM; gfp_mask |= GFP_TRANSHUGE; order = HPAGE_PMD_ORDER; } -- cgit v1.2.3