Re: [patch RT 0/4] rwsem/rt: Lift the single reader restriction

Sebastian Siewior
2017-04-04T14:01:10Z

On 2017-04-01 12:50:58 [+0200], Thomas Gleixner wrote:
> R/W semaphores in RT do not allow multiple readers because a writer
> blocking on the sempahore would have deal with all the readers in terms of
> priority or budget inheritance. While multi reader priority boosting would
> be possible (it has been attempted before), multi reader budget inheritance
> is impossible.
…
> It cures the Radeon mess, lowers the contention on mmap_sem for certain
> workloads and did not have any negative impact in our initial testing on RT
> behaviour.
>
> I think it's worth to expose it to a wider audience of users for testing,
> so we can figure out it whether there are dragons lurking.

series applied.

> Thanks,
>
> tglx

Sebastian