From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760160AbZEMDS7 (ORCPT ); Tue, 12 May 2009 23:18:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756493AbZEMDGf (ORCPT ); Tue, 12 May 2009 23:06:35 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:49519 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756456AbZEMDGb (ORCPT ); Tue, 12 May 2009 23:06:31 -0400 From: KOSAKI Motohiro To: KOSAKI Motohiro Subject: [PATCH 1/4] vmscan: change the number of the unmapped files in zone reclaim Cc: kosaki.motohiro@jp.fujitsu.com, LKML , linux-mm , Andrew Morton , Rik van Riel , Christoph Lameter In-Reply-To: <20090513120155.5879.A69D9226@jp.fujitsu.com> References: <20090513120155.5879.A69D9226@jp.fujitsu.com> Message-Id: <20090513120606.587C.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Wed, 13 May 2009 12:06:28 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Subject: [PATCH] vmscan: change the number of the unmapped files in zone reclaim Documentation/sysctl/vm.txt says A percentage of the total pages in each zone. Zone reclaim will only occur if more than this percentage of pages are file backed and unmapped. This is to insure that a minimal amount of local pages is still available for file I/O even if the node is overallocated. However, zone_page_state(zone, NR_FILE_PAGES) contain some non file backed pages (e.g. swapcache, buffer-head) The right calculation is to use NR_{IN}ACTIVE_FILE. Signed-off-by: KOSAKI Motohiro Cc: Christoph Lameter Cc: Rik van Riel --- mm/vmscan.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) Index: b/mm/vmscan.c =================================================================== --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2397,6 +2397,7 @@ static int __zone_reclaim(struct zone *z .isolate_pages = isolate_pages_global, }; unsigned long slab_reclaimable; + long nr_unmapped_file_pages; disable_swap_token(); cond_resched(); @@ -2409,9 +2410,11 @@ static int __zone_reclaim(struct zone *z reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; - if (zone_page_state(zone, NR_FILE_PAGES) - - zone_page_state(zone, NR_FILE_MAPPED) > - zone->min_unmapped_pages) { + nr_unmapped_file_pages = zone_page_state(zone, NR_INACTIVE_FILE) + + zone_page_state(zone, NR_ACTIVE_FILE) - + zone_page_state(zone, NR_FILE_MAPPED); + + if (nr_unmapped_file_pages > zone->min_unmapped_pages) { /* * Free memory by calling shrink zone with increasing * priorities until we have enough memory freed. @@ -2458,6 +2461,8 @@ int zone_reclaim(struct zone *zone, gfp_ { int node_id; int ret; + long nr_unmapped_file_pages; + long nr_slab_reclaimable; /* * Zone reclaim reclaims unmapped file backed pages and @@ -2469,10 +2474,12 @@ int zone_reclaim(struct zone *zone, gfp_ * if less than a specified percentage of the zone is used by * unmapped file backed pages. */ - if (zone_page_state(zone, NR_FILE_PAGES) - - zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages - && zone_page_state(zone, NR_SLAB_RECLAIMABLE) - <= zone->min_slab_pages) + nr_unmapped_file_pages = zone_page_state(zone, NR_INACTIVE_FILE) + + zone_page_state(zone, NR_ACTIVE_FILE) - + zone_page_state(zone, NR_FILE_MAPPED); + nr_slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (nr_unmapped_file_pages <= zone->min_unmapped_pages && + nr_slab_reclaimable <= zone->min_slab_pages) return 0; if (zone_is_all_unreclaimable(zone))