Re: cgroup tasks file error

[ccmail111 <ccmail111-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>]

--- On Wed, 12/15/10, Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> wrote:

> From: Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Subject: Re: cgroup tasks file error
> To: "ccmail111" <ccmail111-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
> Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
> Date: Wednesday, December 15, 2010, 12:51 PM
> * ccmail111 <ccmail111-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
> [2010-12-14 10:22:32]:
> 
> > 
> > 
> > --- On Tue, 12/14/10, Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> wrote:
> > 
> > > From: Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> > > Subject: Re: cgroup tasks file error
> > > To: "ccmail111" <ccmail111-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
> > > Cc: "Jue Hong" <honshj-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
> containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
> > > Date: Tuesday, December 14, 2010, 12:41 PM
> > > On Tue, Dec 14, 2010 at 11:03 PM,
> > > ccmail111 <ccmail111-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
> > > wrote:
> > > >
> > > > Isn't ns mounted by default ?
> > > > I rebooted machine,
> > > > based on 2.6.32 kernel.
> > > >
> > > > Then,
> > > >
> > > > [host:~]$ mkdir /dev/cgroup
> > > > [host:~]$ mount -t cgroup cpuset
> -ocpuset,ns
> > > /dev/cgroup
> > > > [host:~]$ ps aux | grep libvirt
> > > > root       575  0.6  0.9  88816  2216
> ?    
> > >    Sl   17:28   0:00 myproc --daemon
> > > > root       654  0.0  0.2   4044   664
> ttyS0  
> > >  S+   17:29   0:00 grep libvirt
> > > > [host:~]$ mkdir /dev/cgroup/hello
> > > > [host:~]$ cat /dev/cgroup/hello/tasks
> > > > [host:~]$ echo 0 >
> /dev/cgroup/hello/cpuset.cpus
> > > > [host:~]$ echo 0 >
> /dev/cgroup/hello/cpuset.mems
> > > 
> > > Can you paste the output of
> > > 
> > > cat /dev/cgroup/hello/cpuset.cpus and mems.
> > > 
> > > Also please paste the o/p of
> /dev/cgroup/cpuset.cpus and
> > > mems
> > > 
> > > > [host:~]$ echo 575 >
> /dev/cgroup/hello/tasks
> > > > [host:~]$ cat /dev/cgroup/hello/tasks
> > > > 575
> > > > [host:~]$ id
> > > > uid=0(root) gid=0(root) groups=0(root)
> > > > [host:~]$
> > > >
> > > > Now, I try to move the task out - the
> parent/root:
> > > >
> > > > [host:~]$ echo 575 > /dev/cgroup/tasks
> > > > -bash: echo: write error: Operation not
> permitted
> > > 
> > > can you send us the o/p of
> > > 
> > > ls -al /dev/cgroup
> > > 
> > > and ls -al /dev/cgroup/hello
> > > 
> > > Balbir
> > > 
> > ----
> > 
> > Please find output requested below:
> > 
> > 
> > [host:~]$ mkdir /dev/cgroup/hello
> > [host:~]$ cat /dev/cgroup/hello/tasks
> > [host:~]$ echo 0 > /dev/cgroup/hello/cpuset.cpus
> > [host:~]$ echo 0 > /dev/cgroup/hello/cpuset.mems
> > [host:~]$ echo 575 > /dev/cgroup/hello/tasks
> > [host:~]$ cat /dev/cgroup/hello/tasks
> > 575
> > [host:~]$ id
> > uid=0(root) gid=0(root) groups=0(root)
> > [host:~]$ echo 575 > /dev/cgroup/tasks
> > -bash: echo: write error: Operation not permitted
> > [host:~]$ cat /dev/cgroup/hello/cpuset.cpus
> > 0
> > [host:~]$ cat /dev/cgroup/hello/cpuset.mems
> > 0
> > [host:~]$ cat /dev/cgroup/cpuset.mems
> > 0
> > [host:~]$ cat /dev/cgroup/cpuset.cpus
> > 0
> > [host:~]$ ls -al /dev/cgroup/
> > total 0
> > drwxr-xr-x  3 root root    0 Dec 14
> 17:29 .
> > drwxr-xr-x 11 root root 2980 Dec 14 17:29 ..
> > -r--r--r--  1 root root    0 Dec 14
> 17:29 cgroup.procs
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.cpu_exclusive
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.cpus
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.mem_exclusive
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.mem_hardwall
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.memory_migrate
> > -r--r--r--  1 root root    0 Dec 14
> 17:29 cpuset.memory_pressure
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.memory_pressure_enabled
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.memory_spread_page
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.memory_spread_slab
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.mems
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.sched_load_balance
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 cpuset.sched_relax_domain_level
> > drwxr-xr-x  2 root root    0 Dec 14
> 17:29 hello
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 notify_on_release
> > -rw-r--r--  1 root root    0 Dec 14
> 17:29 release_agent
> > -rw-r--r--  1 root root    0 Dec 14
> 17:31 tasks
> > [host:~]$ ls -al /dev/cgroup/hello/
> > total 0
> > drwxr-xr-x 2 root root 0 Dec 14 17:29 .
> > drwxr-xr-x 3 root root 0 Dec 14 17:29 ..
> > -r--r--r-- 1 root root 0 Dec 14 17:29 cgroup.procs
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.cpu_exclusive
> > -rw-r--r-- 1 root root 0 Dec 14 17:30 cpuset.cpus
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.mem_exclusive
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.mem_hardwall
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.memory_migrate
> > -r--r--r-- 1 root root 0 Dec 14 17:29
> cpuset.memory_pressure
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.memory_spread_page
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.memory_spread_slab
> > -rw-r--r-- 1 root root 0 Dec 14 17:30 cpuset.mems
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.sched_load_balance
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> cpuset.sched_relax_domain_level
> > -rw-r--r-- 1 root root 0 Dec 14 17:29
> notify_on_release
> > -rw-r--r-- 1 root root 0 Dec 14 17:30 tasks
> > [host:~]$ id
> > uid=0(root) gid=0(root) groups=0(root)
> > [host:~]$
> >
> 
> Looks like Serge's ns suggestion solved your problem,
> right? 
> 
> -- 
>     Three Cheers,
>     Balbir
> 

Yes, Balbir, thats right.

IMHO, it would nice if it can be documented on wiki or such.
Thanks everyone for suggestions..