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 [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 Any thoughts !? --- On Tue, 12/14/10, Jue Hong <honshj@xxxxxxxxx> wrote: > From: Jue Hong <honshj@xxxxxxxxx> > Subject: Re: cgroup tasks file error > To: "ccmail111" <ccmail111@xxxxxxxxx> > Cc: "Serge E. Hallyn" <serge.hallyn@xxxxxxxxxxxxx>, "Matt Helsley" <matthltc@xxxxxxxxxx>, containers@xxxxxxxxxxxxxxxxxxxxxxxxxx > Date: Tuesday, December 14, 2010, 4:39 AM > Have you mounted the ns subsys? > The ns subsys will place some restrictions on the task > movement. > > On Tue, Dec 14, 2010 at 3:28 PM, ccmail111 <ccmail111@xxxxxxxxx> > wrote: > > > > Thanks Matt. > > After doing what Serge suggests, I was able to create > a dummy cgroup and > > move task (#580) below to the group. But now.. > > I see another issue: cannot move the task back to its > parent (root), from the group (hello) as in: > > > > I am trying to move back task #580.. > > > > [host:/dev/cgroup]$ id > > uid=0(root) gid=0(root) groups=0(root) > > > > > > [host:/dev/cgroup]$ echo 580 > tasks > > -bash: echo: write error: Operation not permitted > > > > [host:/dev/cgroup]$ cat hello/tasks > > 580 > > 610 > > 2104 > > [host:/dev/cgroup]$ > > > > > > --- On Mon, 12/13/10, Matt Helsley <matthltc@xxxxxxxxxx> > wrote: > > > >> From: Matt Helsley <matthltc@xxxxxxxxxx> > >> Subject: Re: cgroup tasks file error > >> To: "Serge E. Hallyn" <serge.hallyn@xxxxxxxxxxxxx> > >> Cc: "ccmail111" <ccmail111@xxxxxxxxx>, > containers@xxxxxxxxxxxxxxxxxxxxxxxxxx > >> Date: Monday, December 13, 2010, 8:02 PM > >> On Mon, Dec 13, 2010 at 05:16:28PM > >> -0600, Serge E. Hallyn wrote: > >> > Quoting ccmail111 (ccmail111@xxxxxxxxx): > >> > > > >> > > I see error:[host:/dev/cgroup]$ echo 693 > > > >> hello-test/tasks > >> > > -bash: echo: write error: No space left > on > >> device > >> > >> This does seem quite odd so I spent a little time > looking > >> at this and I agree with Serge. > >> > >> > > [host:/dev/cgroup]$ pwd/dev/cgroup > >> > > > >> > > But the user process is up and > running.. > >> > > > >> > > [host:/dev/cgroup]$ ps aux | grep > procroot > >> > >> > > > >> > > 693 Â0.0 Â0.4 Â34720 Â1112 ttyS0  > ÂSl > >> 19:11  0:00 /opt/bin/myproc -ext > >> > > > >> > > Also the cgroup exists and valid.. > >> > > > >> > > [host:/dev/cgroup]$ ls | grep > hello-test > >> > > hello-test > >> > > > >> > > What above error mean and any > suggestions ? > >> > > Please email. > >> > > >> > Which cgroups do you have composed on that > >> mount? I'm guess you > >> > have cpuset, and you need to set the > cpuset.mems and > >> cpuset.cpus. > >> > Until you do that, no tasks can be assigned > to it. > >> > >> I looked a a few places in kernel/cgroup.c which > return > >> ENOSPC > >> or could potentially forward such an error. The > only place > >> that > >> fits is in the attach path and is consistent with > the > >> notion that > >> it's a cpuset issue: > >> > >> echo <pid> > tasks => > >> cgroup_tasks_write() => > >> attach_task_by_pid() => > >> cgroup_attach_task() => (via > ss->can_attach() where > >> ss is the cpuset subsystem) > >> cpuset_can_attach(): > >>     if > >> (cpumask_empty(cs->cpus_allowed) || > >> nodes_empty(cs->mems_allowed)) > >> > >> return -ENOSPC; > >> > >> No other cgroup subsystem that I looked at > (freezer, > >> memcontrol, ns, > >>  blkio, devcgroup) returns ENOSPC when > >> attaching a task. > >> > >> So not only do you need to set those masks but > each mask > >> must have at > >> least one cpu and "mem" respectively. > >> > >> Cheers, > >>  -Matt Helsley > >> > > > > > > > > _______________________________________________ > > Containers mailing list > > Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx > > https://lists.linux-foundation.org/mailman/listinfo/containers > > > > > > -- > Jue Hong (æç) > Department of Network Infrastructure > Tencent Company, Shenzhen, China > _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
