From: Hillf Danton <dhillf@gmail.com>
Date: Thu, 8 Dec 2011 04:41:50 +0000 (+1100)
Subject: mm: compaction: push isolate search base of compact control one pfn ahead
X-Git-Tag: next-20111213~1^2~140
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0bcd436fff07531e190b6451098a355ba94cf80e;p=karo-tx-linux.git

mm: compaction: push isolate search base of compact control one pfn ahead

After isolated the current pfn will no longer be scanned and isolated if
the next round is necessary, so push the isolate_migratepages search base
of the given compact_control one step ahead.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/compaction.c b/mm/compaction.c
index 899d95638586..8f8a5525dcde 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -365,8 +365,10 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 		nr_isolated++;
 
 		/* Avoid isolating too much */
-		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX)
+		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {
+			++low_pfn;
 			break;
+		}
 	}
 
 	acct_isolated(zone, cc);