From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 9C0106B0047 for ; Thu, 2 Sep 2010 10:32:31 -0400 (EDT) Received: by pzk33 with SMTP id 33so117358pzk.14 for ; Thu, 02 Sep 2010 07:32:30 -0700 (PDT) From: Minchan Kim Subject: [RESEND PATCH v2] compaction: handle active and inactive fairly in too_many_isolated Date: Thu, 2 Sep 2010 23:32:11 +0900 Message-Id: <1283437931-11754-1-git-send-email-minchan.kim@gmail.com> Sender: owner-linux-mm@kvack.org To: Andrew Morton , Greg Kroah-Hartman Cc: Mel Gorman , Wu Fengguang , linux-mm , LKML , Iram Shahzad , Minchan Kim List-ID: Iram reported compaction's too_many_isolated loops forever. (http://www.spinics.net/lists/linux-mm/msg08123.html) The meminfo of situation happened was inactive anon is zero. That's because the system has no memory pressure until then. While all anon pages was in active lru, compaction could select active lru as well as inactive lru. That's a different thing with vmscan's isolated. So we has been two too_many_isolated. While compaction can isolated pages in both active and inactive, current implementation of too_many_isolated only considers inactive. It made Iram's problem. This patch handles active and inactive with fair. That's because we can't expect where from and how many compaction would isolated pages. This patch changes (nr_isolated > nr_inactive) with nr_isolated > (nr_active + nr_inactive) / 2. P.S : Mel said "it should be merged and arguably is a stable candidate for 2.6.35" Cc: Iram Shahzad Acked-by: Mel Gorman Acked-by: Wu Fengguang Signed-off-by: Minchan Kim --- mm/compaction.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 94cce51..4d709ee 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -214,15 +214,16 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc) /* Similar to reclaim, but different enough that they don't share logic */ static bool too_many_isolated(struct zone *zone) { - - unsigned long inactive, isolated; + unsigned long active, inactive, isolated; inactive = zone_page_state(zone, NR_INACTIVE_FILE) + zone_page_state(zone, NR_INACTIVE_ANON); + active = zone_page_state(zone, NR_ACTIVE_FILE) + + zone_page_state(zone, NR_ACTIVE_ANON); isolated = zone_page_state(zone, NR_ISOLATED_FILE) + zone_page_state(zone, NR_ISOLATED_ANON); - return isolated > inactive; + return isolated > (inactive + active) / 2; } /* -- 1.7.0.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org