From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753930Ab0IBOcb (ORCPT ); Thu, 2 Sep 2010 10:32:31 -0400 Received: from mail-px0-f174.google.com ([209.85.212.174]:33709 "EHLO mail-px0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152Ab0IBOca (ORCPT ); Thu, 2 Sep 2010 10:32:30 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=nD8ESD9EsHB55E1rqH+xE+DNeM/JqtAi0+4uVZ+s+yXV0SbIy7WdLUrnvirOq9srRl NL4Qb+ME+reHWlr0KuQMDtdyvy3Y9n2LFq4YJ4YTWaNf9Jx8u5/xJfg4DtOFsEK344aQ mVOQqgvTKSyuZfFPvCBNO1xEsMfos3SYXnicg= From: Minchan Kim To: Andrew Morton , Greg Kroah-Hartman Cc: Mel Gorman , Wu Fengguang , linux-mm , LKML , Iram Shahzad , 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> X-Mailer: git-send-email 1.7.0.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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