Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757399AbZD1X3p (ORCPT ); Tue, 28 Apr 2009 19:29:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752037AbZD1X3h (ORCPT ); Tue, 28 Apr 2009 19:29:37 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52023 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998AbZD1X3g (ORCPT ); Tue, 28 Apr 2009 19:29:36 -0400 Date: Tue, 28 Apr 2009 19:29:07 -0400 From: Rik van Riel To: Elladan Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, tytso@mit.edu, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org Subject: [PATCH] vmscan: evict use-once pages first Message-ID: <20090428192907.556f3a34@bree.surriel.com> In-Reply-To: <20090428044426.GA5035@eskimo.com> References: <20090428044426.GA5035@eskimo.com> Organization: Red Hat, Inc. Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1905 Lines: 53 When the file LRU lists are dominated by streaming IO pages, evict those pages first, before considering evicting other pages. This should be safe from deadlocks or performance problems because only three things can happen to an inactive file page: 1) referenced twice and promoted to the active list 2) evicted by the pageout code 3) under IO, after which it will get evicted or promoted The pages freed in this way can either be reused for streaming IO, or allocated for something else. If the pages are used for streaming IO, this pageout pattern continues. Otherwise, we will fall back to the normal pageout pattern. Signed-off-by: Rik van Riel --- Elladan, does this patch fix the issue you are seeing? Peter, Kosaki, Ted, does this patch look good to you? diff --git a/mm/vmscan.c b/mm/vmscan.c index eac9577..4c0304e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1489,6 +1489,21 @@ static void shrink_zone(int priority, struct zone *zone, nr[l] = scan; } + /* + * When the system is doing streaming IO, memory pressure here + * ensures that active file pages get deactivated, until more + * than half of the file pages are on the inactive list. + * + * Once we get to that situation, protect the system's working + * set from being evicted by disabling active file page aging + * and swapping of swap backed pages. We still do background + * aging of anonymous pages. + */ + if (nr[LRU_INACTIVE_FILE] > nr[LRU_ACTIVE_FILE]) { + nr[LRU_ACTIVE_FILE] = 0; + nr[LRU_INACTIVE_ANON] = 0; + } + while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || nr[LRU_INACTIVE_FILE]) { for_each_evictable_lru(l) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/