From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: Re: [PATCH 1/7] [RFC] Support named cgroups hierarchies Date: Wed, 01 Apr 2009 14:24:36 +0800 Message-ID: <49D308A4.3030302@cn.fujitsu.com> References: <20090312104507.24154.71691.stgit@menage.corp.google.com> <20090312105122.24154.73633.stgit@menage.corp.google.com> <49BF46BC.4080302@cn.fujitsu.com> <6599ad830903310112x626252c4je760a80eb1eaa1d@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6599ad830903310112x626252c4je760a80eb1eaa1d-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 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: Paul Menage Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: containers.vger.kernel.org >>> - /* Next check flags */ >>> - if (new->flags != root->flags) >> Is this change intended or unintended? With this change we allow: >> # mount -t cgroup -o cpu xxx /mnt1 >> # mount -t cgroup -o cpu,noprefix xxx /mnt2 >> But files in /mnt2 still prefix with 'cpu.' > > That fits in better with existing semantics for other filesystems - if > you mount an already-mounted device with different superblock mount > options, the new mount still has the superblock options associated > with the old mount. > > Arguably this might mean that we should ignore all options when > mounting a hierarchy by name that already exists, even if you specify > a different set of subsystems from what is mounted. > Then I think it's better to make it a different patch, but not hiding this change in this patch. >>> + /* If we asked for subsystems then they must match */ >>> + if (new->subsys_bits && new->subsys_bits != root->subsys_bits) >>> return 0; >> This has already been checked. > > Where? My mistake, please ignore. :)