From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752463Ab1HLNAE (ORCPT ); Fri, 12 Aug 2011 09:00:04 -0400 Received: from mga14.intel.com ([143.182.124.37]:17112 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349Ab1HLM77 (ORCPT ); Fri, 12 Aug 2011 08:59:59 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,362,1309762800"; d="scan'208";a="37828345" Date: Fri, 12 Aug 2011 20:59:52 +0800 From: Wu Fengguang To: Peter Zijlstra Cc: "linux-fsdevel@vger.kernel.org" , Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Vivek Goyal , Andrea Righi , linux-mm , LKML Subject: Re: [PATCH 2/5] writeback: dirty position control Message-ID: <20110812125952.GA16675@localhost> References: <20110806084447.388624428@intel.com> <20110806094526.733282037@intel.com> <1312811193.10488.33.camel@twins> <20110808141128.GA22080@localhost> <1312814501.10488.41.camel@twins> <20110808230535.GC7176@localhost> <1313153657.6576.40.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1313153657.6576.40.camel@twins> 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 Fri, Aug 12, 2011 at 08:54:17PM +0800, Peter Zijlstra wrote: > On Fri, 2011-08-12 at 00:56 +0200, Peter Zijlstra wrote: > > > > s - x 3 > > f(x) := 1 + (-----) > > d > > > btw, if you want steeper slopes for rampup and brake you can add another > factor like: > > s - x 3 > f(x) := 1 + a(-----) > d > > And solve the whole f(l)=0 thing again to determine d in l and a. > > For 0 < a < 1 the slopes increase. Yes, we can leave it as a future tuning option. For now I'm pretty satisfied with the current function's shape :) Thanks, Fengguang From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 2/5] writeback: dirty position control Date: Fri, 12 Aug 2011 20:59:52 +0800 Message-ID: <20110812125952.GA16675@localhost> References: <20110806084447.388624428@intel.com> <20110806094526.733282037@intel.com> <1312811193.10488.33.camel@twins> <20110808141128.GA22080@localhost> <1312814501.10488.41.camel@twins> <20110808230535.GC7176@localhost> <1313153657.6576.40.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-fsdevel@vger.kernel.org" , Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Vivek Goyal , Andrea Righi , linux-mm , LKML To: Peter Zijlstra Return-path: Content-Disposition: inline In-Reply-To: <1313153657.6576.40.camel@twins> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Fri, Aug 12, 2011 at 08:54:17PM +0800, Peter Zijlstra wrote: > On Fri, 2011-08-12 at 00:56 +0200, Peter Zijlstra wrote: > > > > s - x 3 > > f(x) := 1 + (-----) > > d > > > btw, if you want steeper slopes for rampup and brake you can add another > factor like: > > s - x 3 > f(x) := 1 + a(-----) > d > > And solve the whole f(l)=0 thing again to determine d in l and a. > > For 0 < a < 1 the slopes increase. Yes, we can leave it as a future tuning option. For now I'm pretty satisfied with the current function's shape :) 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org