Re: [RFC PATCH 07/12] locking/lockdep: Add support for nested terminal locks

Peter Zijlstra
2018-11-11T01:30:25Z

On Sat, Nov 10, 2018 at 07:30:54PM -0500, Waiman Long wrote:
> On 11/10/2018 09:20 AM, Peter Zijlstra wrote:
> > On Thu, Nov 08, 2018 at 03:34:23PM -0500, Waiman Long wrote:
> >> There are use cases where we want to allow 2-level nesting of one
> >> terminal lock underneath another one. So the terminal lock type is now
> >> extended to support a new nested terminal lock where it can allow the
> >> acquisition of another regular terminal lock underneath it.
> > You're stretching things here... If you're allowing things under it, it
> > is no longer a terminal lock.
> >
> > Why would you want to do such a thing?
>
> A majority of the gain in debugobjects is to make the hash lock a kind
> of terminal lock. Yes, I may be stretching it a bit here. I will take
> back the nesting patch and consider doing that in a future patch.

Maybe try and write a better changelog? I'm not following, but that
could also be because I've been awake for almost 20 hours :/