Re: [for-next][PATCH 10/15] tracing: Allow perf to read synthetic events

[Steven Rostedt]

On Fri, 22 May 2026 08:19:36 -0700
Ian Rogers <irogers@xxxxxxxxxx> wrote:

> On Fri, May 22, 2026 at 7:35 AM Steven Rostedt <rostedt@xxxxxxxxxx> wrote:
> >
> > From: Steven Rostedt <rostedt@xxxxxxxxxxx>
> >
> > Currently, perf can not enable synthetic events. When it does, it either
> > causes a warning in the kernel or errors with "no such device".
> >
> > Add the necessary code to allow perf to also attach to synthetic events.  
> 
> Thanks so much for doing this work! I hoped to spend some time testing
> it, but there's never enough time. For the synthetic event I was

I totally understand not having time. Heck, I'm currently unemployed and
I'm still having a hard time finding time!

> wondering what values end up in the perf sample like 'period'? I can

You mean to poll on the event?

> imagine this being the case and that, if you are doing something like
> a futex wait duration, having to interpret the raw data rather than
> just getting aggregation for free in `perf report` via the period.
> That's not wrong but I was just curious.

I guess I'm not quite sure what you mean by "the period". But then again, I
don't use perf that much.

-- Steve