Re: [PATCH v3 2/4] perf: Enqueue SIGTRAP always via task_work.

[Sebastian Andrzej Siewior]

On 2024-04-10 13:37:05 [+0200], Frederic Weisbecker wrote:
> > Couldn't we either flush _or_ remove the task_work in perf_release()?
> 
> Right so the problem in perf_release() is that we may be dealing with task works
> of other tasks than current. In that case, task_work_cancel() is fine if it
> successes. But if it fails, you don't have the guarantee that the task work
> isn't concurrently running or about to run. And you have no way to know about
> that. So then you need some sort of flushing indeed.

Since perf_release() preemptible, a wait/sleep for completion would be
best (instead of flushing).

> Thanks.
> 
> > > Thanks.

Sebastian