[PATCH] mm: compact: remove watermark check at compact suitable

[Chen Feng]

There are two paths calling this function.
For direct compact, there is no need to check the zone watermark here.
For kswapd wakeup kcompactd, since there is a reclaim before this.
It makes sense to do compact even the watermark is ok at this time.

Signed-off-by: Chen Feng <puck.chen@xxxxxxxxxxxxx>
---
 mm/compaction.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 8fa2540..cb322df 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1260,13 +1260,6 @@ static unsigned long __compaction_suitable(struct zone *zone, int order,
 		return COMPACT_CONTINUE;
 
 	watermark = low_wmark_pages(zone);
-	/*
-	 * If watermarks for high-order allocation are already met, there
-	 * should be no need for compaction at all.
-	 */
-	if (zone_watermark_ok(zone, order, watermark, classzone_idx,
-								alloc_flags))
-		return COMPACT_PARTIAL;
 
 	/*
 	 * Watermarks for order-0 must be met for compaction. Note the 2UL.
-- 
1.9.1