[PATCH][BUGFIX] cgroups: fix pid namespace bug

[Li Zefan]

Paul Menage wrote:
> Thanks Li - but as I said to Serge in the email when I brought this up
> originally, I already had a patch in mind for this; I've had an intern
> (Ben) at Google working on it. His patch (pretty much ready, and being
> sent out tomorrow I hope) is pretty similar to yours, but his is on
> top of another patch that provides a (currently read-only)
> "cgroup.procs" file in each cgroup dir that lists the unique tgids in
> the cgroup. So the key in the list of pid arrays is actually a pid_ns
> and a file type (indicating procs or tasks) rather than just a pid_ns.
> 
> So I think it makes more sense to not use this patch, but to use the
> pair of patches that Ben's written, since they provide more overal
> functionality.
> 

It's fine for me. I waited for your fix for a week or so but didn't see
it, so I thought you were stuck in other business and I did this fix.