From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH RFC] fsio: filesystem io accounting cgroup Date: Mon, 8 Jul 2013 10:00:47 -0700 Message-ID: <20130708170047.GA18600@mtj.dyndns.org> References: <20130708100046.14417.12932.stgit@zurg> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=cYOoyNE+Iqb0QPIigGmN7eTyLKVnPU5YV3lwgrYbKSw=; b=rDxMfYCiY8CVZd6uw1+ff3Hy90LUoYYfOqUIf4X9OIPjMDyJV4rfpocu+VrWk3YgKk iOfxsmZDgv8haRPJre3vK+o4KkqDBQeAAWHOvmorIBvzv1M4R8WnzOegogCm4Nb8QLUj YJtwsmXI0yYb7kKgIH8QgaQdKDomtZ8TW8QuUBW6m3tnGF/JTmd58sDxfFxEmGZJFZkw t9JYe7kH8aviSSJ+FBNmLajhT+yUImm65Qs3lvy8DXItDAAGvm8zX97S0GHuafogM1fU cT7owYNPdrM0loWxzBLOz8vllAfYu5uzrUt+GGIR5kknEFVWtsKGE5oZZRfDCfuwcHYv lpoQ== Content-Disposition: inline In-Reply-To: <20130708100046.14417.12932.stgit@zurg> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Konstantin Khlebnikov Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton , Sha Zhengju , devel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, Vivek Goyal , Jens Axboe (cc'ing Vivek and Jens) Hello, On Mon, Jul 08, 2013 at 02:01:39PM +0400, Konstantin Khlebnikov wrote: > This is proof of concept, just basic functionality for IO controller. > This cgroup will control filesystem usage on vfs layer, it's main goal is > bandwidth control. It's supposed to be much more lightweight than memcg/blkio. While blkcg is pretty heavy handed right now, there's no inherent reason for it to be that way. The right thing to do would be updating blkcg to be light-weight rather than adding yet another controller. Also, all controllers should support full hierarchy. > Unlike to blkio this method works for all of filesystems, not just disk-backed. > Also it's able to handle writeback, because each inode has context which can be > used in writeback thread to account io operations. Again, a problem to be fixed in the stack rather than patching up from up above. The right thing to do is to propagate pressure through bdi properly and let whatever is backing the bdi generate appropriate amount of pressure, be that disk or network. > This is early prototype, I have some plans about extra functionality because > this accounting itself is mostly useless, but it can be used as basis for more > usefull features. I'm afraid it'd have very low chance of making upstream. If this area of work is interesting / important, please look into improving blkcg rather than working around it. Thanks. -- tejun