Commit 9933a0c8 authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds

mm/migrate: clear __GFP_RECLAIM to make the migration callback consistent with...

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: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1594622517-20681-5-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d92bbc27
...@@ -1554,6 +1554,11 @@ struct page *new_page_nodemask(struct page *page, ...@@ -1554,6 +1554,11 @@ struct page *new_page_nodemask(struct page *page,
} }
if (PageTransHuge(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; gfp_mask |= GFP_TRANSHUGE;
order = HPAGE_PMD_ORDER; order = HPAGE_PMD_ORDER;
} }
......
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