Re: [PATCH 0/6] Backport rework of deadline bandwidth restoration for 5.10.y

[Qais Yousef]

On 08/20/23 12:24, Waiman Long wrote:
> 
> On 8/20/23 11:21, Qais Yousef wrote:
> > This is a backport of the series that fixes the way deadline bandwidth
> > restoration is done which is causing noticeable delay on resume path. It also
> > converts the cpuset lock back into a mutex which some users on Android too.
> > I lack the details but AFAIU the read/write semaphore was slower on high
> > contention.
> 
> Note that it was a percpu rwsem before this patch series. It was not a
> regular rwsem. Percpu rwsem isn't designed to handle high write lock
> contention. A regular rwsem should be similar to mutex in performance when
> handling high write lock contention.

Thanks a lot for the clarification Waiman! Much appreciated.


Cheers

--
Qais Yousef