From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFD] cgroup: about multiple hierarchies Date: Tue, 28 Feb 2012 22:53:59 +0100 Message-ID: <1330466039.11248.103.camel@twins> References: <20120221211938.GE12236@google.com> <20120222163858.GB4128@redhat.com> <20120222165714.GC4128@redhat.com> <1329990094.24994.64.camel@twins> <20120223213847.GK19691@redhat.com> <20120223223457.GJ22536@google.com> <20120228211627.GH9920@redhat.com> <1330464100.11248.94.camel@twins> <20120228213526.GI9920@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120228213526.GI9920-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Vivek Goyal Cc: Frederic Weisbecker , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Kay Sievers , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christoph Hellwig , Lennart Poettering , Tejun Heo , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton On Tue, 2012-02-28 at 16:35 -0500, Vivek Goyal wrote: > Yes this is how scheduler does to handle hierarchy. Treat task and group > at same level. ... > Whether it is a good thing or bad thing, I don't know. That's IMO what the cgroupfs interface provides for, if you do anything different there's this shadow group that contains the tasks for which you then have to provide extra parameter control. Furthermore, by treating tasks and groups at the same level you can create the extra group, but you can't do the reverse. So its the more versatile solution as well. > I think previous > design was allocating a group for every user. I guess, in that case we > will have fixed % share of each user (until and unless users are created/ > removed). Not even, it depended on if the user had anything runnable or not. It was very much like the current cgroup stuff if you create a cgroup for each user and stick the tasks in. The cpu-cgroup stuff is purely runnable based, so every wakeup/sleep changes the entire weight distribution, yay! :-)