Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756879Ab0GVVUL (ORCPT ); Thu, 22 Jul 2010 17:20:11 -0400 Received: from cantor.suse.de ([195.135.220.2]:39066 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507Ab0GVVUJ (ORCPT ); Thu, 22 Jul 2010 17:20:09 -0400 Date: Thu, 22 Jul 2010 14:18:56 -0700 From: Greg KH To: Vivek Goyal Cc: Paul Menage , Li Zefan , Lennart Poettering , Kay Sievers , Andrew Morton , KAMEZAWA Hiroyuki , Ben Blum , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "Daniel P. Berrange" , Jan Safranek , Balbir Singh Subject: Re: [PATCH] cgroupfs: create /sys/fs/cgroup to mount cgroupfs on Message-ID: <20100722211856.GA1297@suse.de> References: <20100722182638.GA12712@kroah.com> <20100722183614.GA5443@suse.de> <20100722193741.GA2688@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20100722193741.GA2688@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2399 Lines: 56 On Thu, Jul 22, 2010 at 03:37:41PM -0400, Vivek Goyal wrote: > On Thu, Jul 22, 2010 at 11:36:15AM -0700, Greg KH wrote: > > On Thu, Jul 22, 2010 at 11:31:07AM -0700, Paul Menage wrote: > > > On Thu, Jul 22, 2010 at 11:26 AM, Greg KH wrote: > > > > We really shouldn't be asking userspace to create new root filesystems. > > > > So follow along with all of the other in-kernel filesystems, and provide > > > > a mount point in sysfs. > > > > > > > > For cgroupfs, this should be in /sys/fs/cgroup/ ?This change provides > > > > that mount point when the cgroup filesystem is registered in the kernel. > > > > > > But cgroups will typically have multiple mounts, with different > > > resource controllers/options on each mount. That doesn't really fit in > > > with this scheme. > > > > Really? I see systems mounting it at /cgroups/ in the filesystem today. > > Where are you expecting it to be mounted at? > > > > Greg, > > [CCing few more folks who might be interested in this dicussion ] > > We do want to retain facility to mount different controllers at different > mount points. We were discussing the other day that in libvirt we might > want to mount block IO controller and network controller separately as > by default we will not put a new virtual machine in a cgroup of its own > because of the penatly involved. That's fine, I'm not changing that ability at all. We just need a "default" mount point for "normal" users. > For other controllers like cpu, memory etc, libvirt automatically puts > each new virtual machine in a cgroup of own. So this is one use case > where we might want to mount different controllers at different mount > points. > > For my testing I now always use /cgroup/ and create directories under it > /cgroup/blkio /cgroup/cpu etc and mount controllers on respective > directories. Lennart and Kay, is this what systemd is doing? I really don't think we should be adding a root /cgroup/ mount point to the system for something like this. Maybe /dev/cgroup/ is better to use, as that way users can create sub-mount points easier. They can't do that in /sys/fs/cgroup/ thanks, greg k-h -- 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/