From 10ad16e14fdbe47ac36f7e55ae72ed59ae73ed0c Mon Sep 17 00:00:00 2001 Message-Id: <10ad16e14fdbe47ac36f7e55ae72ed59ae73ed0c.1307455422.git.minchan.kim@gmail.com> In-Reply-To: References: From: Minchan Kim Date: Sun, 5 Jun 2011 17:53:00 +0900 Subject: [PATCH v3 04/10] compaction: make isolate_lru_page with filter aware In async mode, compaction doesn't migrate dirty or writeback pages. So, it's meaningless to pick the page and re-add it to lru list. Of course, when we isolate the page in compaction, the page might be dirty or writeback but when we try to migrate the page, the page would be not dirty, writeback. So it could be migrated. But it's very unlikely as isolate and migration cycle is much faster than writeout. So, this patch helps cpu and prevent unnecessary LRU churning. Cc: Andrea Arcangeli Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: KOSAKI Motohiro Acked-by: Johannes Weiner Acked-by: Mel Gorman Acked-by: Rik van Riel Signed-off-by: Minchan Kim --- mm/compaction.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index f0d75e9..8079346 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -243,6 +243,7 @@ static unsigned long isolate_migratepages(struct zone *zone, unsigned long last_pageblock_nr = 0, pageblock_nr; unsigned long nr_scanned = 0, nr_isolated = 0; struct list_head *migratelist = &cc->migratepages; + enum ISOLATE_MODE mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE; /* Do not scan outside zone boundaries */ low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn); @@ -326,9 +327,11 @@ static unsigned long isolate_migratepages(struct zone *zone, continue; } + if (!cc->sync) + mode |= ISOLATE_CLEAN; + /* Try isolate the page */ - if (__isolate_lru_page(page, - ISOLATE_ACTIVE|ISOLATE_INACTIVE, 0) != 0) + if (__isolate_lru_page(page, mode, 0) != 0) continue; VM_BUG_ON(PageTransCompound(page)); -- 1.7.0.4