From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753373Ab0HSVJ3 (ORCPT ); Thu, 19 Aug 2010 17:09:29 -0400 Received: from mga01.intel.com ([192.55.52.88]:3206 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751789Ab0HSVJ0 (ORCPT ); Thu, 19 Aug 2010 17:09:26 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.56,235,1280732400"; d="scan'208";a="598369618" Date: Fri, 20 Aug 2010 05:09:07 +0800 From: Wu Fengguang To: Johannes Weiner Cc: Matthew Wilcox , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "Li, Shaohua" Subject: Re: [TESTCASE] Clean pages clogging the VM Message-ID: <20100819210907.GA22747@localhost> References: <20100809133000.GB6981@wil.cx> <20100817195001.GA18817@linux.intel.com> <20100818141308.GD1779@cmpxchg.org> <20100818160613.GE9431@localhost> <20100818160731.GA15002@localhost> <20100819115106.GG1779@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100819115106.GG1779@cmpxchg.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 19, 2010 at 07:51:06PM +0800, Johannes Weiner wrote: > I am currently trying to get rid of all the congestion_wait() in the VM. > They are used for different purposes, so they need different replacement > mechanisms. > > I saw Shaohua's patch to make congestion_wait() cleverer. But I really > think that congestion is not a good predicate in the first place. Why > would the VM care about IO _congestion_? It needs a bunch of pages to > complete IO, whether the writing device is congested is not really > useful information at this point, I think. I have the same feeling that the congestion_wait() calls are not pertinent ones. I'm glad to see people working on that exploring all possible replacement schemes. Thanks, Fengguang From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 52A416B02BF for ; Thu, 19 Aug 2010 17:09:17 -0400 (EDT) Date: Fri, 20 Aug 2010 05:09:07 +0800 From: Wu Fengguang Subject: Re: [TESTCASE] Clean pages clogging the VM Message-ID: <20100819210907.GA22747@localhost> References: <20100809133000.GB6981@wil.cx> <20100817195001.GA18817@linux.intel.com> <20100818141308.GD1779@cmpxchg.org> <20100818160613.GE9431@localhost> <20100818160731.GA15002@localhost> <20100819115106.GG1779@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100819115106.GG1779@cmpxchg.org> Sender: owner-linux-mm@kvack.org To: Johannes Weiner Cc: Matthew Wilcox , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "Li, Shaohua" List-ID: On Thu, Aug 19, 2010 at 07:51:06PM +0800, Johannes Weiner wrote: > I am currently trying to get rid of all the congestion_wait() in the VM. > They are used for different purposes, so they need different replacement > mechanisms. > > I saw Shaohua's patch to make congestion_wait() cleverer. But I really > think that congestion is not a good predicate in the first place. Why > would the VM care about IO _congestion_? It needs a bunch of pages to > complete IO, whether the writing device is congested is not really > useful information at this point, I think. I have the same feeling that the congestion_wait() calls are not pertinent ones. I'm glad to see people working on that exploring all possible replacement schemes. Thanks, Fengguang -- 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