From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: Re: [PATCH] cgroup: fix to allow mounting a hierarchy by name Date: Thu, 29 Dec 2011 10:50:06 +0800 Message-ID: <4EFBD55E.5030106@cn.fujitsu.com> References: <4EF9291D.7030208@cn.fujitsu.com> <20111227163535.GA17712@google.com> <4EFAB2E2.4040008@cn.fujitsu.com> <20111228163631.GN17712@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20111228163631.GN17712-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: LKML , Cgroups Tejun Heo wrote: > Hello, Li. > > On Wed, Dec 28, 2011 at 02:10:42PM +0800, Li Zefan wrote: >> The "name" option was introduced along with the "none" option, so we >> can distinguish between different cgroup hierarchies which have no >> bound subsystems, like this: >> >> # mount -t cgroup -o none,name=hier1 xxx /cgroup1 >> # mount -t cgroup -o none,name=hier2 xxx /cgroup2 >> >> As the name is unique, we have this "mount by hierarchy name" feature. > > I could be missing something but does that add anything other than > naming convenience? > The name option is necessary, otherwise how can we mount hierarchies as shown in the above example? >> It looks reasonable, but I guess few people know this feature. We can >> live with it, as it only saves us some typing when mounting an existing >> hierarchy. On the other hand, removing this small feature can hardly >> result in code reduction. > > If it's a redundant feature which has been broken over a year without > anyone complaining, it really doesn't need to exist. It might not > save a lot of code but would save some WTH moments. > The redundant feature is mouting existing hierarchies by specifying name only, and the cleanup patch I sent has this feature removed in effect. kernel/cgroup.c | 15 +++++++-------- 1 files changed, 7 insertions(+), 8 deletions(-) This is why I'm not so keen to remove the feature.