From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262743AbVAFF7h (ORCPT ); Thu, 6 Jan 2005 00:59:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262744AbVAFF7h (ORCPT ); Thu, 6 Jan 2005 00:59:37 -0500 Received: from fw.osdl.org ([65.172.181.6]:27838 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S262743AbVAFF7d (ORCPT ); Thu, 6 Jan 2005 00:59:33 -0500 Date: Wed, 5 Jan 2005 21:59:09 -0800 From: Andrew Morton To: Andrea Arcangeli Cc: nickpiggin@yahoo.com.au, riel@redhat.com, marcelo.tosatti@cyclades.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH][5/?] count writeback pages in nr_scanned Message-Id: <20050105215909.7ac1f8b1.akpm@osdl.org> In-Reply-To: <20050106054659.GS4597@dualathlon.random> References: <41DCB577.9000205@yahoo.com.au> <20050105202611.65eb82cf.akpm@osdl.org> <41DCC014.80007@yahoo.com.au> <20050105204706.0781d672.akpm@osdl.org> <20050106045932.GN4597@dualathlon.random> <20050105210539.19807337.akpm@osdl.org> <20050106051707.GP4597@dualathlon.random> <41DCCA68.3020100@yahoo.com.au> <20050105213207.721b1aae.akpm@osdl.org> <20050106054659.GS4597@dualathlon.random> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > > But I dislike code that works by luck, yup, it is code which works by luck. And it's a bit inaccurate - there is potential for (small) further latency improvement in there. But we do need to watch the CPU consumption in there - end_page_writeback() already figures fairly high sometimes. > and sure I could demonstrate it > if I bothered to write an artificial testcase on simulated hardware. Could well be so.