Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760034AbZDGGm1 (ORCPT ); Tue, 7 Apr 2009 02:42:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757553AbZDGGmR (ORCPT ); Tue, 7 Apr 2009 02:42:17 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56845 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753068AbZDGGmQ (ORCPT ); Tue, 7 Apr 2009 02:42:16 -0400 Message-ID: <49DAF54A.10909@cn.fujitsu.com> Date: Tue, 07 Apr 2009 14:40:10 +0800 From: Gui Jianfeng User-Agent: Thunderbird 2.0.0.5 (Windows/20070716) MIME-Version: 1.0 To: Vivek Goyal CC: nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, jens.axboe@oracle.com, ryov@valinux.co.jp, fernando@intellilink.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, arozansk@redhat.com, jmoyer@redhat.com, oz-kernel@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, akpm@linux-foundation.org, menage@google.com, peterz@infradead.org Subject: Re: [RFC] IO Controller References: <1236823015-4183-1-git-send-email-vgoyal@redhat.com> <49D45DAC.2060508@cn.fujitsu.com> <20090402140037.GC12851@redhat.com> <49DAAF25.8010702@cn.fujitsu.com> In-Reply-To: <49DAAF25.8010702@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3004 Lines: 75 Gui Jianfeng wrote: > Vivek Goyal wrote: >> On Thu, Apr 02, 2009 at 02:39:40PM +0800, Gui Jianfeng wrote: >>> Vivek Goyal wrote: >>>> Hi All, >>>> >>>> Here is another posting for IO controller patches. Last time I had posted >>>> RFC patches for an IO controller which did bio control per cgroup. >>>> >>>> http://lkml.org/lkml/2008/11/6/227 >>>> >>>> One of the takeaway from the discussion in this thread was that let us >>>> implement a common layer which contains the proportional weight scheduling >>>> code which can be shared by all the IO schedulers. >>>> >>> >>> Hi Vivek, >>> >>> I did some tests on my *old* i386 box(with two concurrent dd running), and notice >>> that IO Controller doesn't work fine in such situation. But it can work perfectly >>> in my *new* x86 box. I dig into this problem, and i guess the major reason is that >>> my *old* i386 box is too slow, it can't ensure two running ioqs are always backlogged. >> Hi Gui, >> >> Have you run top to see what's the percentage cpu usage. I suspect that >> cpu is not keeping up pace disk to enqueue enough requests. I think >> process might be blocked somewhere else so that it could not issue >> requests. >> >>> If that is the case, I happens to have a thought. when an ioq uses up it time slice, >>> we don't expire it immediately. May be we can give a piece of bonus time for idling >>> to wait new requests if this ioq's finish time and its ancestor's finish time are all >>> much smaller than other entities in each corresponding service tree. >> Have you tried it with "fairness" enabled? With "fairness" enabled, for >> sync queues I am waiting for one extra idle time slice "8ms" for queue >> to get backlogged again before I move to the next queue? >> >> Otherwise try to increase the idle time length to higher value say "12ms" >> just to see if that has any impact. >> >> Can you please also send me output of blkparse. It might give some idea >> how IO schedulers see IO pattern. > > Hi Vivek, > > Sorry for the late reply, I tried the "fairness" patch, it seems not working. > I'v also tried to extend the idle value, not working either. > The blktrace output is attached. It seems that the high priority ioq is deleting > from busy tree too often due to lacking of requests. My box is single CPU and CPU > speed is a little slow. May be two concurrent dd is contending CPU to submit > requests, that's the reason for not always backlogged for ioqs. Hi Vivek, Sorry for bothering, there were some configure errors when i tested, and got the improper result. The "fairness" patch seems to work fine now! It makes the high priority ioq *always* backlogged :) > >> Thanks >> Vivek >> >> >> > -- Regards Gui Jianfeng -- 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/