From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754142Ab0HZPkd (ORCPT ); Thu, 26 Aug 2010 11:40:33 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:54217 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754127Ab0HZPkb (ORCPT ); Thu, 26 Aug 2010 11:40:31 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=vZmhJczSnBQEvejAxgMBdVOX7oyTHVPEz8dUa7t2D4sNnrBvohNTcJdiJ7yadkz74b mMtL7K85tBeVduYGxtHEFxx7pJo6ZXWrK1YGeB/1Oq4cz3hdeCqozM3urPlE9jHZEV8f N1x5J1fbWyVw/8r5HPDpgTWTdm5FQ1wec+HFo= From: Minchan Kim To: Andrew Morton , Greg Kroah-Hartman Cc: Linux Kernel List , linux-mm@kvack.org, Mel Gorman , Wu Fengguang , Minchan Kim , Iram Shahzad Subject: [PATCH v2] compaction: handle active and inactive fairly in too_many_isolated Date: Fri, 27 Aug 2010 00:40:01 +0900 Message-Id: <1282837201-6707-1-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