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

[Waiman Long]

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.

Cheers,
Longman