From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: [PATCH] block: transfer source bio's cgroup tags to clone via bio_associate_blkcg() (was: Re: blkio cgroups controller doesn't work with LVM?) Date: Wed, 2 Mar 2016 14:18:27 -0500 Message-ID: <20160302191827.GC3476@redhat.com> References: <56CDF283.9010802@windriver.com> <56CEB1BC.4000005@kyup.com> <20160225145314.GA20699@redhat.com> <20160302160649.GB29826@mtj.duckdns.org> <20160302175656.GA59991@redhat.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Nikolay Borisov Cc: Mike Snitzer , Tejun Heo , Chris Friesen , device-mapper development , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jens Axboe , SiteGround Operations On Wed, Mar 02, 2016 at 08:03:10PM +0200, Nikolay Borisov wrote: > Thanks for the patch I will likely have time to test this sometime next week. > But just to be sure - the expected behavior would be that processes > writing to dm-based devices would experience the fair-shair > scheduling of CFQ (provided that the physical devices that back those > DM devices use CFQ), correct? Nikolay, I am not sure how well it will work with CFQ of underlying device. It will get cgroup information right for buffered writes. But cgroup information for reads and direct writes will come from submitter's context and if dm layer gets in between, then many a times submitter might be a worker thread and IO will be attributed to that worker's cgroup (root cgroup). Give it a try anyway. Thanks Vivek