From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754165Ab1GVM5b (ORCPT ); Fri, 22 Jul 2011 08:57:31 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50748 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753756Ab1GVM5a convert rfc822-to-8bit (ORCPT ); Fri, 22 Jul 2011 08:57:30 -0400 Subject: Re: [PATCH 8/8] mm: vmscan: Do not writeback filesystem pages from kswapd From: Peter Zijlstra To: Mel Gorman Cc: Linux-MM , LKML , XFS , Dave Chinner , Christoph Hellwig , Johannes Weiner , Wu Fengguang , Jan Kara , Rik van Riel , Minchan Kim In-Reply-To: <1311265730-5324-9-git-send-email-mgorman@suse.de> References: <1311265730-5324-1-git-send-email-mgorman@suse.de> <1311265730-5324-9-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 22 Jul 2011 14:57:12 +0200 Message-ID: <1311339432.27400.36.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-07-21 at 17:28 +0100, Mel Gorman wrote: > Assuming that flusher threads will always write back dirty pages promptly > then it is always faster for reclaimers to wait for flushers. This patch > prevents kswapd writing back any filesystem pages. That is a somewhat sort changelog for such a big assumption ;-) I think it can use a few extra words to explain the need to clean pages from @zone vs writeback picks whatever fits best on disk and how that works out wrt the assumption. What requirements does this place on writeback and how does it meet them.