Re: [PATCH v3 3/8] coresight: etm-perf: Flush workqueue before unloading module

On 13/08/2026 15:19, Leo Yan wrote:
> On Tue, Jul 28, 2026 at 04:00:15PM +0100, James Clark wrote:
>> The work queue is never flushed on module unload, so pending work items
>> can run after coresight-config is cleaned up or the .text section is
>> unloaded. The global workqueue also can't be flushed manually, so change
>> it to a local workqueue and flush it on exit.
> 
> Why can't we drop the workqueue if it introduces race conditions and
> complexity? In particular, I don't see much benefit from deferring
> the resource release.
> 
> According to the comment in __rb_free_aux(), the free_aux() callback
> should never be called from atomic context. It should be safe to release
> the resources directly from the free_aux() callback, without going
> through a workqueue.
> 
> Thanks,
> Leo

Nice catch. This was fixed in Perf core in 95ff4ca26c49, very shortly 
after the Coresight Perf mode was merged. I'll change this commit to 
drop the workqueue completely.