Re: [PATCH] perf auxtrace: Fix auxtrace queue conflict

Arnaldo Carvalho de Melo
2021-03-09T12:36:55Z

Em Mon, Mar 08, 2021 at 08:54:37AM -0800, Andi Kleen escreveu:
> On Mon, Mar 08, 2021 at 05:11:43PM +0200, Adrian Hunter wrote:
> > The only requirement of an auxtrace queue is that the buffers are in
> > time order. That is achieved by making separate queues for separate
> > perf buffer or AUX area buffer mmaps.
> >
> > That generally means a separate queue per cpu for per-cpu contexts,
> > and a separate queue per thread for per-task contexts.
> >
> > When buffers are added to a queue, perf checks that the buffer cpu
> > and thread id (tid) match the queue cpu and thread id.
> >
> > However, generally, that need not be true, and perf will queue
> > buffers correctly anyway, so the check is not needed.
> >
> > In addition, the check gets erroneously hit when using sample mode
> > to trace multiple threads.
> >
> > Consequently, fix that case by removing the check.
>
> Thanks!
>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>

Thanks, applied.

- Arnaldo