From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754251AbZJCJBd (ORCPT ); Sat, 3 Oct 2009 05:01:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753778AbZJCJBc (ORCPT ); Sat, 3 Oct 2009 05:01:32 -0400 Received: from mail-gx0-f212.google.com ([209.85.217.212]:44016 "EHLO mail-gx0-f212.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829AbZJCJBb convert rfc822-to-8bit (ORCPT ); Sat, 3 Oct 2009 05:01:31 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=EYhkmTncmbhxf/S2Osl6AKjbEhqTVT3tqDG89zHkEL4UqDKXwvFSKqln3Ku1gGsDkB sPztbOeLrUC1GnPkwF94IXvzS3+YuyzX4BPZE3aM38ULUAWuSa9l99zxA7Xx5M/MgnMM qj6hO/2h5LBtT9rXXLJ6lYC1jLOUrfEm85HPk= MIME-Version: 1.0 In-Reply-To: <20091003072540.GW31616@kernel.dk> References: <20091002172046.GA2376@elte.hu> <20091002172554.GJ31616@kernel.dk> <20091002172842.GA4884@elte.hu> <20091002173732.GK31616@kernel.dk> <1254507215.8667.7.camel@marge.simson.net> <20091002181903.GN31616@kernel.dk> <1254548931.8299.18.camel@marge.simson.net> <20091003072021.GB21407@elte.hu> <20091003072540.GW31616@kernel.dk> Date: Sat, 3 Oct 2009 11:01:35 +0200 Message-ID: <4e5e476b0910030201k23760da4ke7d6d08662382cf1@mail.gmail.com> Subject: Re: IO scheduler based IO controller V10 From: Corrado Zoccolo To: Jens Axboe Cc: Ingo Molnar , Mike Galbraith , Linus Torvalds , Vivek Goyal , Ulrich Lukas , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, agk@redhat.com, akpm@linux-foundation.org, peterz@infradead.org, jmarchan@redhat.com, riel@redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jens, On Sat, Oct 3, 2009 at 9:25 AM, Jens Axboe wrote: > On Sat, Oct 03 2009, Ingo Molnar wrote: >> >> * Mike Galbraith wrote: >> >> >     unsigned int cfq_desktop; >> > +   unsigned int cfq_desktop_dispatch; >> >> > -   if (cfq_cfqq_idle_window(cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) >> > +   if (cfq_cfqq_idle_window(cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) { >> > +           cfqd->desktop_dispatch_ts = jiffies; >> >             return 0; >> > +   } >> >> btw., i hope all those desktop_ things will be named latency_ pretty >> soon as the consensus seems to be - the word 'desktop' feels so wrong in >> this context. >> >> 'desktop' is a form of use of computers and the implication of good >> latencies goes far beyond that category of systems. > > I will rename it, for now it doesn't matter (lets not get bogged down in > bike shed colors, please). > > Oh and Mike, I forgot to mention this in the previous email - no more > tunables, please. We'll keep this under a single knob. Did you have a look at my http://patchwork.kernel.org/patch/47750/ ? It already introduces a 'target_latency' tunable, expressed in ms. If we can quantify the benefits of each technique, we could enable them based on the target latency requested by that single tunable. Corrado > > -- > Jens Axboe > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html > Please read the FAQ at  http://www.tux.org/lkml/ > -- __________________________________________________________________________ dott. Corrado Zoccolo mailto:czoccolo@gmail.com PhD - Department of Computer Science - University of Pisa, Italy --------------------------------------------------------------------------