[Devel] Re: [PATCH] procfs: Do not release pid_ns->proc_mnt too early

Louis Rilling Louis.Rilling at kerlabs.com
Fri Jun 18 01:27:38 PDT 2010


On 17/06/10 23:36 +0200, Oleg Nesterov wrote:
> On 06/17, Eric W. Biederman wrote:
> >
> > The task->children isn't changed until __unhash_process() which runs
> > after flush_proc_task().
> 
> Yes. But this is only the current implementation detail.
> It would be nice to cleanup the code so that EXIT_DEAD tasks are
> never sit in ->children list.
> 
> > So we should be able to come up with
> > a variant of do_wait() that zap_pid_ns_processes can use that does
> > what we need.
> 
> See above...
> 
> Even if we modify do_wait() or add the new variant, how the caller
> can wait for EXIT_DEAD tasks? I don't think we want to modify
> release_task() to do __wake_up_parent() or something similar.

Indeed, I was thinking about calling __wake_up_parent() from release_task()
once parent->children becomes empty.

Not sure about the performance impact though. Maybe some WAIT_NO_CHILDREN flag
in parent->signal could limit it. But if EXIT_DEAD children are removed from
->children before release_task(), I'm afraid that this becomes impossible.

Thanks,

Louis

-- 
Dr Louis Rilling			Kerlabs
Skype: louis.rilling			Batiment Germanium
Phone: (+33|0) 6 80 89 08 23		80 avenue des Buttes de Coesmes
http://www.kerlabs.com/			35700 Rennes
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Digital signature
URL: <http://lists.openvz.org/pipermail/devel/attachments/20100618/7a30a9f2/attachment-0001.sig>
-------------- next part --------------
_______________________________________________
Containers mailing list
Containers at lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/containers


More information about the Devel mailing list