From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx172.postini.com [74.125.245.172]) by kanga.kvack.org (Postfix) with SMTP id C2B8A6B0031 for ; Tue, 9 Jul 2013 09:15:19 -0400 (EDT) Received: by mail-la0-f44.google.com with SMTP id er20so4747544lab.3 for ; Tue, 09 Jul 2013 06:15:18 -0700 (PDT) Message-ID: <51DC0CE2.2050906@openvz.org> Date: Tue, 09 Jul 2013 17:15:14 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH RFC] fsio: filesystem io accounting cgroup References: <20130708100046.14417.12932.stgit@zurg> <20130708170047.GA18600@mtj.dyndns.org> <20130708175201.GB9094@redhat.com> <20130708175607.GB18600@mtj.dyndns.org> <51DBC99F.4030301@openvz.org> <20130709125734.GA2478@htj.dyndns.org> In-Reply-To: <20130709125734.GA2478@htj.dyndns.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Vivek Goyal , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , cgroups@vger.kernel.org, Andrew Morton , Sha Zhengju , devel@openvz.org, Jens Axboe Tejun Heo wrote: > Hello, > > On Tue, Jul 09, 2013 at 12:28:15PM +0400, Konstantin Khlebnikov wrote: >> Yep, blkio has plenty problems and flaws and I don't get how it's related >> to vfs layer, dirty set control and non-disk or network backed filesystems. >> Any problem can be fixed by introducing new abstract layer, except too many >> abstraction levels. Cgroup is pluggable subsystem, blkio has it's own plugins >> and it's build on top of io scheduler plugin. All this stuff always have worked > > What does that have to do with anything? > >> with block devices. Now you suggest to handle all filesystems in this stack. >> I think binding them to unrealated cgroup is rough leveling violation. > > How is blkio unrelated to filesystems mounted on block devices? > You're suggesting a duplicate solution which can't be complete. blkio controls block devices. not filesystems or superblocks or bdi or pagecache. It's all about block layer and nothing more. Am I right? So, you want to link some completely unrelated subsystems like NFS into the block layer? > >> NFS cannot be controlled only by network throttlers because we >> cannot slow down writeback process when it happens, we must slow >> down tasks who generates dirty memory. > > That's exactly the same problem why blkio doesn't work for async IOs > right now, so if you're interested in the area, please contribute to > fixing that problem. > >> Plus it's close to impossible to separate several workloads if they >> share one NFS sb. > > Again, the same problem with blkio. We need separate pressure > channels on bdi for each cgroup. > > Thanks. > -- 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