From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755408Ab0HXPbn (ORCPT ); Tue, 24 Aug 2010 11:31:43 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:55637 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507Ab0HXPbk (ORCPT ); Tue, 24 Aug 2010 11:31:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=noG5AjgZbe3+cwY8c+pPG7TMhn1BQElbQ7gyowKV/mr3KarZWBRoCbvcvajRZ6iiwU n4GXDHps/Hxt28yN8vT1JREKO+gHieVMWdsKqhDIuq7E+dZVCndpsNHX4DrzvJyLLhBg rkUseh6cCFrF58dCTYLDoOSAm7Qo31sM6HOmk= From: Minchan Kim To: Andrew Morton Cc: Linux Kernel List , linux-mm@kvack.org, Mel Gorman , Wu Fengguang , Minchan Kim , Iram Shahzad Subject: [PATCH v2 1/2] compaction: handle active and inactive fairly in too_many_isolated Date: Wed, 25 Aug 2010 00:31:18 +0900 Message-Id: <1282663879-4130-1-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 different things 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. 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