From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757995AbYAHVOj (ORCPT ); Tue, 8 Jan 2008 16:14:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754148AbYAHVKj (ORCPT ); Tue, 8 Jan 2008 16:10:39 -0500 Received: from mx1.redhat.com ([66.187.233.31]:47704 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753971AbYAHVKh (ORCPT ); Tue, 8 Jan 2008 16:10:37 -0500 Message-Id: <20080108210005.558041779@redhat.com> References: <20080108205939.323955454@redhat.com> User-Agent: quilt/0.46-1 Date: Tue, 08 Jan 2008 15:59:46 -0500 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Subject: [patch 07/19] (NEW) add some sanity checks to get_scan_ratio Content-Disposition: inline; filename=rvr-04-linux-2.6-scan-ratio-fixes.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The access ratio based scan rate determination in get_scan_ratio works ok in most situations, but needs to be corrected in some corner cases: - if we run out of swap space, do not bother scanning the anon LRUs - if we have already freed all of the page cache, we need to scan the anon LRUs Signed-off-by: Rik van Riel Index: linux-2.6.24-rc6-mm1/mm/vmscan.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/vmscan.c 2008-01-07 17:33:50.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/vmscan.c 2008-01-07 17:57:49.000000000 -0500 @@ -1182,7 +1182,7 @@ static unsigned long shrink_list(enum lr static void get_scan_ratio(struct zone *zone, struct scan_control * sc, unsigned long *percent) { - unsigned long anon, file; + unsigned long anon, file, free; unsigned long anon_prio, file_prio; unsigned long rotate_sum; unsigned long ap, fp; @@ -1230,6 +1230,20 @@ static void get_scan_ratio(struct zone * else if (fp > 100) fp = 100; percent[1] = fp; + + free = zone_page_state(zone, NR_FREE_PAGES); + + /* + * If we have no swap space, do not bother scanning anon pages + */ + if (nr_swap_pages <= 0) + percent[0] = 0; + /* + * If we already freed most file pages, scan the anon pages + * regardless of the page access ratios or swappiness setting. + */ + else if (file + free <= zone->pages_high) + percent[0] = 100; } -- All Rights Reversed