+ mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/migrate: clear __GFP_RECLAIM to make the migration callback consistent with regular THP allocations
has been added to the -mm tree.  Its filename is
     mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch

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------------------------------------------------------
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
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.

Link: http://lkml.kernel.org/r/1594622517-20681-5-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/mm/migrate.c~mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations
+++ a/mm/migrate.c
@@ -1550,6 +1550,11 @@ struct page *new_page_nodemask(struct pa
 	}
 
 	if (PageTransHuge(page)) {
+		/*
+		 * clear __GFP_RECALIM to make the migration callback
+		 * consistent with regular THP allocations.
+		 */
+		gfp_mask &= ~__GFP_RECLAIM;
 		gfp_mask |= GFP_TRANSHUGE;
 		order = HPAGE_PMD_ORDER;
 	}
_

Patches currently in -mm which might be from iamjoonsoo.kim@lge.com are

mm-page_isolation-prefer-the-node-of-the-source-page.patch
mm-migrate-move-migration-helper-from-h-to-c.patch
mm-hugetlb-unify-migration-callbacks.patch
mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch
mm-migrate-make-a-standard-migration-target-allocation-function.patch
mm-mempolicy-use-a-standard-migration-target-allocation-callback.patch
mm-page_alloc-remove-a-wrapper-for-alloc_migration_target.patch
mm-memory-failure-remove-a-wrapper-for-alloc_migration_target.patch
mm-memory_hotplug-remove-a-wrapper-for-alloc_migration_target.patch