From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758056AbZEABSZ (ORCPT ); Thu, 30 Apr 2009 21:18:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753341AbZEABSQ (ORCPT ); Thu, 30 Apr 2009 21:18:16 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:33092 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751633AbZEABSP (ORCPT ); Thu, 30 Apr 2009 21:18:15 -0400 Date: Thu, 30 Apr 2009 18:13:40 -0700 From: Andrew Morton To: Rik van Riel Cc: 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: <20090430181340.6f07421d.akpm@linux-foundation.org> In-Reply-To: <20090430205936.0f8b29fc@riellaptop.surriel.com> References: <20090428044426.GA5035@eskimo.com> <20090428192907.556f3a34@bree.surriel.com> <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> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) 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 Thu, 30 Apr 2009 20:59:36 -0400 Rik van Riel wrote: > On Thu, 30 Apr 2009 17:45:36 -0700 > Andrew Morton wrote: > > > Were you able to tell whether altering /proc/sys/vm/swappiness > > appropriately regulated the rate at which the mapped page count > > decreased? > > That should not make a difference at all for mapped file > pages, after the change was merged that makes the VM ignores > the referenced bit of mapped active file pages. > > Ever since the split LRU code was merged, all that the > swappiness controls is the aggressiveness of file vs > anonymous LRU scanning. Which would cause exactly the problem Elladan saw? > Currently the kernel has no effective code to protect the > page cache working set from streaming IO. Elladan's bug > report shows that we do need some kind of protection... Seems to me that reclaim should treat swapcache-backed mapped mages in a similar fashion to file-backed mapped pages? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id AA0C66B003D for ; Thu, 30 Apr 2009 21:17:41 -0400 (EDT) Date: Thu, 30 Apr 2009 18:13:40 -0700 From: Andrew Morton Subject: Re: [PATCH] vmscan: evict use-once pages first (v2) Message-Id: <20090430181340.6f07421d.akpm@linux-foundation.org> In-Reply-To: <20090430205936.0f8b29fc@riellaptop.surriel.com> References: <20090428044426.GA5035@eskimo.com> <20090428192907.556f3a34@bree.surriel.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: elladan@eskimo.com, peterz@infradead.org, linux-kernel@vger.kernel.org, tytso@mit.edu, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org List-ID: On Thu, 30 Apr 2009 20:59:36 -0400 Rik van Riel wrote: > On Thu, 30 Apr 2009 17:45:36 -0700 > Andrew Morton wrote: > > > Were you able to tell whether altering /proc/sys/vm/swappiness > > appropriately regulated the rate at which the mapped page count > > decreased? > > That should not make a difference at all for mapped file > pages, after the change was merged that makes the VM ignores > the referenced bit of mapped active file pages. > > Ever since the split LRU code was merged, all that the > swappiness controls is the aggressiveness of file vs > anonymous LRU scanning. Which would cause exactly the problem Elladan saw? > Currently the kernel has no effective code to protect the > page cache working set from streaming IO. Elladan's bug > report shows that we do need some kind of protection... Seems to me that reclaim should treat swapcache-backed mapped mages in a similar fashion to file-backed mapped pages? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org