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