Re: [PATCHSET v3 driver-core-next] kernfs, sysfs, driver-core: implement synchronous self-removal

Greg KH
2014-01-13T22:50:00Z

On Mon, Jan 13, 2014 at 04:17:15PM -0500, Tejun Heo wrote:
> On Sat, Jan 11, 2014 at 01:45:13PM -0500, Tejun Heo wrote:
> > Hey, Greg.
> >
> > On Fri, Jan 10, 2014 at 04:19:53PM -0800, Greg KH wrote:
> > > > It's really late in the -rc cycle for me to take this for 3.14, but I
> > > > see patch 1 is a good one to have, so I'll take that now, and queue the
> > > > rest up for after 3.14-rc1 is out for 3.15. Is that ok with you, or do
> > > > you have patches that depend on this series for 3.14?
> > >
> > > Oh nevermind, these are all good, now applied :)
> >
> > I don't have anything depending on the series for the up coming merge
> > window so 3.15 merge window would have been fine but 3.14 merge
> > windows wokrs too. :)
>
> Greg, I'm sorry but can you please revert the whole series?
> get_active() waiting while a node is deactivated has potential to lead
> to deadlock and that deactivate/reactivate interface is something
> fundamentally flawed and that cgroup will have to work with the
> remove_self() like everybody else. IOW, I think the first posting was
> correct.
>
> I think we better defer this to the next window and I'll do the whole
> thing - kernfs updates & cgroup conversion - together and then push
> out patches so that I don't repeat these mistakes.
>
> Sorry about the mess. I got tunnel-visioned thinking about cgroup
> semantics too much.

No worries, but it is sad, I really liked seeing that odd "remove self"
function go away. I've now reverted all 15 patches, please verify that
I didn't mess anything up in my tree somehow.

thanks,

greg k-h