From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 6072B6B0047 for ; Wed, 1 Sep 2010 09:51:25 -0400 (EDT) Message-ID: <4C7E5A52.7080806@redhat.com> Date: Wed, 01 Sep 2010 09:51:14 -0400 From: Rik van Riel MIME-Version: 1.0 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: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Hugh Dickins , Johannes Weiner , LKML , linux-mm , Andrew Morton List-ID: 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 -- 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