From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932186AbWLLKyp (ORCPT ); Tue, 12 Dec 2006 05:54:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932188AbWLLKyp (ORCPT ); Tue, 12 Dec 2006 05:54:45 -0500 Received: from nigel.suspend2.net ([203.171.70.205]:40502 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932186AbWLLKyo (ORCPT ); Tue, 12 Dec 2006 05:54:44 -0500 Subject: [PATCH] Vmscan.c: Account for memory already freed in seeking to free more. From: Nigel Cunningham Reply-To: nigel@suspend2.net To: LKML Content-Type: text/plain Date: Tue, 12 Dec 2006 21:54:41 +1100 Message-Id: <1165920881.7318.2.camel@nigel.suspend2.net> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The current versions of shrink_all_zones and shrink_all_memory don't take account of memory already freed when making multiple calls to seek to free memory. As a result, we can end up freeing far more memory than was asked for. This can in turn result in more (unnecessary) paging if/when the data is later needed. These modifications seek to alleviate this situation by modifying swap_cluster_max by the number of pages freed by shrink_inactive_list in shrink_all_zones before proceeding to the next zone, and in shrink_all_memory before shrinking slab and going to the next priority. Signed-off-by: Nigel Cunningham diff -ruNp 930-vmscan.patch-old/mm/vmscan.c 930-vmscan.patch-new/mm/vmscan.c @@ -1469,9 +1469,12 @@ static unsigned long shrink_all_zones(un zone->nr_scan_inactive += (zone->nr_inactive >> prio) + 1; if (zone->nr_scan_inactive >= nr_pages || pass > 3) { + int freed; zone->nr_scan_inactive = 0; nr_to_scan = min(nr_pages, zone->nr_inactive); - ret += shrink_inactive_list(nr_to_scan, zone, sc); + freed = shrink_inactive_list(nr_to_scan, zone, sc); + ret += freed; + sc->swap_cluster_max -= freed; if (ret >= nr_pages) return ret; } @@ -1550,9 +1553,14 @@ unsigned long shrink_all_memory(unsigned for (prio = DEF_PRIORITY; prio >= 0; prio--) { unsigned long nr_to_scan = nr_pages - ret; + int freed; sc.nr_scanned = 0; - ret += shrink_all_zones(nr_to_scan, prio, pass, &sc); + sc.swap_cluster_max = nr_pages - ret; + freed = shrink_all_zones(nr_to_scan, prio, pass, &sc); + ret += freed; + lru_pages =- freed; + nr_to_scan = nr_pages - ret; if (ret >= nr_pages) goto out;