From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752327AbZECDZm (ORCPT ); Sat, 2 May 2009 23:25:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751238AbZECDZd (ORCPT ); Sat, 2 May 2009 23:25:33 -0400 Received: from mx2.redhat.com ([66.187.237.31]:40347 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbZECDZd (ORCPT ); Sat, 2 May 2009 23:25:33 -0400 Date: Sat, 2 May 2009 23:24:03 -0400 From: Rik van Riel To: Wu Fengguang Cc: Andrew Morton , elladan@eskimo.com, peterz@infradead.org, linux-kernel@vger.kernel.org, tytso@mit.edu, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org Subject: Re: [PATCH] vmscan: evict use-once pages first (v2) Message-ID: <20090502232403.3ca10b97@riellaptop.surriel.com> In-Reply-To: <20090503031539.GC5702@localhost> References: <1240987349.4512.18.camel@laptop> <20090429114708.66114c03@cuia.bos.redhat.com> <20090430072057.GA4663@eskimo.com> <20090430174536.d0f438dd.akpm@linux-foundation.org> <20090430205936.0f8b29fc@riellaptop.surriel.com> <20090430181340.6f07421d.akpm@linux-foundation.org> <20090430215034.4748e615@riellaptop.surriel.com> <20090430195439.e02edc26.akpm@linux-foundation.org> <49FB01C1.6050204@redhat.com> <20090501123541.7983a8ae.akpm@linux-foundation.org> <20090503031539.GC5702@localhost> 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 On Sun, 3 May 2009 11:15:39 +0800 Wu Fengguang wrote: > Commit 7e9cd484204f(vmscan: fix pagecache reclaim referenced bit > check) tries to address scalability problem when every page get > mapped and referenced, so that logic(which lowed the priority of > mapped pages) could be enabled only on conditions like (priority < > DEF_PRIORITY). > > Or preferably we can explicitly protect the mapped executables, > as illustrated by this patch (a quick prototype). Over time, given enough streaming IO and idle applications, executables will still be evicted with just this patch. However, a combination of your patch and mine might do the trick. I suspect that executables are never a very big part of memory, except on small memory systems, so protecting just the mapped executables should not be a scalability problem. My patch in combination with your patch should make sure that if something gets evicted from the active list, it's not executables - meanwhile, lots of the time streaming IO will completely leave the active file list alone. -- All rights reversed.