From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754476Ab0HWQOR (ORCPT ); Mon, 23 Aug 2010 12:14:17 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:56482 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754458Ab0HWQOQ (ORCPT ); Mon, 23 Aug 2010 12:14:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=HOtn4O0Lo2z39O+i0LbCYPAVpG04xiWtKGZLSUkuYwAb58U3/okrGF89GiK2wTgPoF 0Ls5FsJakVNykyg03QeCE2ceFBc/h+IpY95RMyzDbetv/VZEKUD7KpWrZk4ycP8j2VHm FWA2r4nhSN2E+CPuDNj1/7FWkwFsnMHAaVHaQ= From: Minchan Kim To: Andrew Morton Cc: Linux Kernel List , linux-mm@kvack.org, Iram Shahzad , Mel Gorman , Wu Fengguang , Minchan Kim Subject: [PATCH] compaction: handle active and inactive fairly in too_many_isolated Date: Tue, 24 Aug 2010 01:13:48 +0900 Message-Id: <1282580028-1940-1-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. 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