Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760263Ab1CDVe3 (ORCPT ); Fri, 4 Mar 2011 16:34:29 -0500 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:60268 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760195Ab1CDVe2 (ORCPT ); Fri, 4 Mar 2011 16:34:28 -0500 Message-ID: <4D715ADF.10509@kernel.dk> Date: Fri, 04 Mar 2011 22:34:23 +0100 From: Jens Axboe MIME-Version: 1.0 To: Vivek Goyal CC: Justin TerAvest , Chad Talbott , Nauman Rafique , Divyesh Shah , lkml , Gui Jianfeng , Corrado Zoccolo , KAMEZAWA Hiroyuki , Greg Thelen Subject: Re: Per iocontext request descriptor limits (Was: Re: RFC: default group_isolation to 1, remove option) References: <20110301142002.GB25699@redhat.com> <4D6F0ED0.80804@kernel.dk> <20110303153007.GF16720@redhat.com> <4D6FB751.3010608@kernel.dk> <20110303165717.GA19527@redhat.com> <20110303180328.GH16720@redhat.com> <4D70C695.4040205@kernel.dk> <20110304213147.GH5466@redhat.com> In-Reply-To: <20110304213147.GH5466@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1950 Lines: 47 On 2011-03-04 22:31, Vivek Goyal wrote: > On Fri, Mar 04, 2011 at 12:01:41PM +0100, Jens Axboe wrote: >> On 2011-03-03 19:03, Vivek Goyal wrote: >>> On Thu, Mar 03, 2011 at 11:57:17AM -0500, Vivek Goyal wrote: >>> >>> [..] >>>>> For now it's not a complicated effort, I already have a patch for this. >>>>> If page tracking needs extra complexity, it'll have to remain in the >>>>> page tracking code. >>>> >>>> Great. I am hoping once you get some free time, you will cleanup and post >>>> that patch. >>> >>> Hmmm..., Now I got interested in this stuff. In case you would like to see >>> your patch to be in and finding it hard to find time to clean it up, I can >>> do that and repost and also fix any bugs. >> >> I did an initial run on the plane: >> >> http://git.kernel.dk/?p=linux-2.6-block.git;a=shortlog;h=refs/heads/for-2.6.39/ioc-rq-alloc >> >> Not tested at all, so there are likely a few bugs. Congestion is gone, >> we'll need to consider that. Before the device was either congested or >> not congested, now the question to ask would be "is the device congested >> for ME" as the answer will depend on who is asking. > > > Thanks Jens. I was having a quick look and noticed that ioc->count[] state > is global across queues. I guess what we want is to keep track of ioc > state per queue (something like cfq_io_context). By maintaining per device > state in ioc, we can also tell whether a particular ioc is congested or > not on a specific device. Indeed, similar to how we setup cfq_io_contexts would be useful there... Requires a bit of thinking. I updated the patchset btw, found some silly errors in it. But yes, we definitely need some better ->count[] tracking. -- 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/