Re: [PATCH] cgroups: handle failure of cgroup_populate_dir() at mount/remount

[Li Zefan <lizf@cn.fujitsu.com>]

Paul Menage wrote:
> On Fri, May 22, 2009 at 1:25 AM, KAMEZAWA Hiroyuki
> <kamezawa.hiroyu@jp.fujitsu.com> wrote:
>> Hm, shouldn't we allow "noprefix" to be effective only agaisnt cpuset ?
>> I think it's just for backward-compatibility of cpuset.
>> (I don't like the option at all.)
> 
> Yes, exposing the "noprefix" option externally was one of the mistakes
> I made when developing cgroups.
> 
> It seems to me really unlikely that anyone is using "noprefix" for

And "noprefix" is not documented in cgroups.txt, so I guess not
many people know this option. Even libcgroup doesn't handle it.

> anything other than implicitly when mounting the "cpuset" filesystem.
> So I'd be inclined to just forbid it if we're mounting more than just
> the cpuset subsystem. A bit of a nasty abstraction violation, but it
> makes more sense overall. The only problem is that someone *might* be
> using it - do we have any way to determine how, and how big do they
> have to be before we care?
> 

I think we can never know..