When the compaction is activated via /proc/sys/vm/compact_memory
it would better scan the whole zone.
And some platform, for instance ARM, has the start_pfn of a zone is zero.
Therefore the first try to compaction via /proc doesn't work.
It needs to force to reset compaction scanner position at first.

Signed-off-by: Gioh Kim <gioh....@lge.com>
Acked-by: Vlastimil Babka <vba...@suse.cz>
Acked-by: David Rientjes <rient...@google.com>
---
 mm/compaction.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mm/compaction.c b/mm/compaction.c
index 8c0d945..ccf48ce 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1587,6 +1587,14 @@ static void __compact_pgdat(pg_data_t *pgdat, struct 
compact_control *cc)
                INIT_LIST_HEAD(&cc->freepages);
                INIT_LIST_HEAD(&cc->migratepages);
 
+               /*
+                * When called via /proc/sys/vm/compact_memory
+                * this makes sure we compact the whole zone regardless of
+                * cached scanner positions.
+                */
+               if (cc->order == -1)
+                       __reset_isolation_suitable(zone);
+
                if (cc->order == -1 || !compaction_deferred(zone, cc->order))
                        compact_zone(zone, cc);
 
-- 
1.7.9.5

--
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/

Reply via email to