Messages in this thread | | | Date | Mon, 27 Feb 2012 19:57:25 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 2/2] cgroup: Walk task list under tasklist_lock in cgroup_enable_task_cg_list |
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On Wed, Feb 22, 2012 at 07:03:27PM +0100, Oleg Nesterov wrote: > Hi. > > Sorry, currently I do not have the time to even read this discussion, > just one note, > > On 02/22, Frederic Weisbecker wrote: > > > > On Tue, Feb 21, 2012 at 05:19:34PM -0800, Paul E. McKenney wrote: > > > On Wed, Feb 22, 2012 at 01:55:28AM +0100, Frederic Weisbecker wrote: > > > > On Tue, Feb 21, 2012 at 02:23:43PM -0800, Mandeep Singh Baines wrote: > > > > > Frederic Weisbecker (fweisbec@gmail.com) wrote: > > > > > > Walking through the tasklist in cgroup_enable_task_cg_list() inside > > > > > > an RCU read side critical section is not enough because: > > > > > > > > > > > > - RCU is not (yet) safe against while_each_thread() > > Yes. Except I'd say it is while_each_thread() who is not safe ;)
Right.
> > Please do not take this into account. This should be fixed, I hope > to send the fix "soon".
Sure, but anyway we need the read_lock here for ordering/commiting reasons.
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