On 10/07/2014 11:33 AM, Vlastimil Babka wrote:
Deferred compaction is employed to avoid compacting zone where sync direct
compaction has recently failed. As such, it makes sense to only defer when
a full zone was scanned, which is when compact_zone returns with
COMPACT_COMPLETE. It's less useful to defer when compact_zone returns with
apparent success (COMPACT_PARTIAL), followed by a watermark check failure,
which can happen due to parallel allocation activity. It also does not make
much sense to defer compaction which was completely skipped (COMPACT_SKIP) for
being unsuitable in the first place.
This patch therefore makes deferred compaction trigger only when
COMPACT_COMPLETE is returned from compact_zone(). Results of stress-highalloc
becnmark show the difference is within measurement error, so the issue is
rather cosmetic.
Signed-off-by: Vlastimil Babka <vba...@suse.cz>
Cc: Minchan Kim <minc...@kernel.org>
Cc: Mel Gorman <mgor...@suse.de>
Cc: Joonsoo Kim <iamjoonsoo....@lge.com>
Cc: Michal Nazarewicz <min...@mina86.com>
Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Christoph Lameter <c...@linux.com>
Cc: Rik van Riel <r...@redhat.com>
Cc: David Rientjes <rient...@google.com>
Acked-by: Rik van Riel <r...@redhat.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
