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authorZi Yan <ziy@nvidia.com>2020-11-14 09:51:43 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-11-14 22:26:03 +0300
commitd20bdd571ee5c9966191568527ecdb1bd4b52368 (patch)
treed34960496812c3fee82d7fd56136ebe5638ac5a6 /mm
parent38935861d85a4d9a353d1dd5a156c97700e2765d (diff)
downloadlinux-d20bdd571ee5c9966191568527ecdb1bd4b52368.tar.xz
mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate
In isolate_migratepages_block, if we have too many isolated pages and nr_migratepages is not zero, we should try to migrate what we have without wasting time on isolating. In theory it's possible that multiple parallel compactions will cause too_many_isolated() to become true even if each has isolated less than COMPACT_CLUSTER_MAX, and loop forever in the while loop. Bailing immediately prevents that. [vbabka@suse.cz: changelog addition] Fixes: 1da2f328fa64 (“mm,thp,compaction,cma: allow THP migration for CMA allocations”) Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Yang Shi <shy828301@gmail.com> Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/compaction.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index d549a4521edf..13cb7a961b31 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -817,6 +817,10 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* delay for some time until fewer pages are isolated
*/
while (unlikely(too_many_isolated(pgdat))) {
+ /* stop isolation if there are still pages not migrated */
+ if (cc->nr_migratepages)
+ return 0;
+
/* async migration should just abort */
if (cc->mode == MIGRATE_ASYNC)
return 0;