Commit 1d2047fe authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode

At present MIGRATE_SYNC_LIGHT is allowing __isolate_lru_page() to
isolate a PageWriteback page, which __unmap_and_move() then rejects with
-EBUSY: of course the writeback might complete in between, but that's
not what we usually expect, so probably better not to isolate it.

When tested by stress-highalloc from mmtests, this has reduced the
number of page migrate failures by 60-70%.

Link: http://lkml.kernel.org/r/20160721073614.24395-2-vbabka@suse.cz


Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7c7fd825
......@@ -1200,7 +1200,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
struct page *page;
const isolate_mode_t isolate_mode =
(sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) |
(cc->mode == MIGRATE_ASYNC ? ISOLATE_ASYNC_MIGRATE : 0);
(cc->mode != MIGRATE_SYNC ? ISOLATE_ASYNC_MIGRATE : 0);
/*
* Start at where we last stopped, or beginning of the zone as
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment