Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for direct descendants

From	James Bottomley <James.Bottomley@HansenPartnership.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for direct descendants
Date	2016-07-21 17:40 +0200
Message-ID	<rXoeS-TM-7@gated-at.bofh.it> (permalink)
References	(6 earlier) <rXnCa-kD-31@gated-at.bofh.it> <rXnLP-DS-9@gated-at.bofh.it> <rXnLP-DS-15@gated-at.bofh.it> <rXnVw-Jo-9@gated-at.bofh.it> <rXo5c-Qr-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Thu, 2016-07-21 at 11:26 -0400, Tejun Heo wrote:
> Hello, James.
> 
> On Thu, Jul 21, 2016 at 08:16:34AM -0700, James Bottomley wrote:
> > > That'd be one side.  The other side is the one moving.  Let's say 
> > > the system admin thing wants to move all processe from A proper 
> > > to B.   It would do that by draining processes from A's procs 
> > > file into B's and even that is multistep and can race.
> > 
> > So the second part is that once we allow the creation of
> > subdirectories, there's no unified tasks file, so there's no way of
> > draining A proper without enumerating and descending into the 
> > cgroupns created subtrees in A?
> 
> Not that.  If it races, it will end up moving processes which are no
> longer in A proper.

So if I as the cgroup ns owner am moving a task from A to A_subdir, the
admin scanning tasks in all of A may miss this task in motion because
all the tasks files can't be scanned atomically?

James

Thread

[PATCH v1 0/3] cgroup: allow for unprivileged management Aleksa Sarai <asarai@suse.de> - 2016-07-18 18:20 +0200
  [PATCH v1 3/3] cgroup: relax common ancestor restriction for direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-18 18:20 +0200
    Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-20 18:00 +0200
      Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-21 01:00 +0200
        Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 01:10 +0200
          Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-21 01:20 +0200
            Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 01:20 +0200
              Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-21 09:50 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-21 16:40 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants "Serge E. Hallyn" <serge@hallyn.com> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants "Serge E. Hallyn" <serge@hallyn.com> - 2016-07-21 16:40 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-21 17:00 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:00 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:00 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-21 17:20 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 17:30 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-21 17:40 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 18:00 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-21 20:20 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-21 23:10 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-22 10:30 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-25 20:40 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Aleksa Sarai <asarai@suse.de> - 2016-07-22 10:20 +0200
                Re: [PATCH v1 3/3] cgroup: relax common ancestor restriction for  direct descendants Tejun Heo <tj@kernel.org> - 2016-07-25 20:50 +0200

csiph-web