From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755472Ab0IANvf (ORCPT ); Wed, 1 Sep 2010 09:51:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41343 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754673Ab0IANvc (ORCPT ); Wed, 1 Sep 2010 09:51:32 -0400 Message-ID: <4C7E5A52.7080806@redhat.com> Date: Wed, 01 Sep 2010 09:51:14 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.8) Gecko/20100806 Fedora/3.1.2-1.fc13 Lightning/1.0b2pre Thunderbird/3.1.2 MIME-Version: 1.0 To: KOSAKI Motohiro CC: Hugh Dickins , Johannes Weiner , LKML , linux-mm , Andrew Morton Subject: Re: [PATCH] vmscan,tmpfs: treat used once pages on tmpfs as used once References: <20100901103653.974C.A69D9226@jp.fujitsu.com> In-Reply-To: <20100901103653.974C.A69D9226@jp.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/31/2010 09:37 PM, KOSAKI Motohiro wrote: > When a page has PG_referenced, shrink_page_list() discard it only > if it is no dirty. This rule works completely fine if the backend > filesystem is regular one. PG_dirty is good signal that it was used > recently because flusher thread clean pages periodically. In addition, > page writeback is costly rather than simple page discard. > > However, When a page is on tmpfs, this heuristic don't works because > flusher thread don't writeback tmpfs pages. then, tmpfs pages always > rotate lru twice at least and it makes unnecessary lru churn. Merely > tmpfs streaming io shouldn't cause large anonymous page swap-out. > > This patch remove this unncessary reclaim bonus of tmpfs pages. > > Cc: Hugh Dickins > Cc: Johannes Weiner > Cc: Rik van Riel > Signed-off-by: KOSAKI Motohiro Reviewed-by: Rik van Riel -- All rights reversed