RE: [PATCH V7 3/6] perf, x86: handle multiple records in PEBS buffer

Liang, Kan
2015-05-05T16:36:58Z

> On Tue, May 05, 2015 at 03:07:23PM +0200, Peter Zijlstra wrote:
> > On Mon, Apr 20, 2015 at 04:07:47AM -0400, Kan Liang wrote:
> > > From: Yan, Zheng <zheng.z.yan@intel.com>
> > > +static void perf_log_lost(struct perf_event *event) {
> > > + struct perf_output_handle handle;
> > > + struct perf_sample_data sample;
> > > + int ret;
> > > +
> > > + struct {
> > > + struct perf_event_header header;
> > > + u64 id;
> > > + u64 lost;
> > > + } lost_event = {
> > > + .header = {
> > > + .type = PERF_RECORD_LOST,
> > > + .misc = 0,
> > > + .size = sizeof(lost_event),
> > > + },
> > > + .id = event->id,
> > > + .lost = 1,
> > > + };
> > > +
> > > + perf_event_header__init_id(&lost_event.header, &sample,
> event);
> > > +
> > > + ret = perf_output_begin(&handle, event,
> > > + lost_event.header.size);
> > > + if (ret)
> > > + return;
> > > +
> > > + perf_output_put(&handle, lost_event);
> > > + perf_event__output_id_sample(event, &handle, &sample);
> > > + perf_output_end(&handle);
> > > +}
> >
> > RECORDs are generic, and should live in the core code.
> >
> > Also, you should introduce this RECORD in a separate patch.
>
> On that, this is lacking a RECORD definition in
> include/uapi/linux/perf_event.h:perf_event_type

The PERF_RECORD_LOST already defined in perf_event_type.
Are you suggesting to add a new dedicated RECORD type, like PERF_RECORD_COLLISION?
Or update the definition about PERF_RECORD_LOST?

Thanks,
Kan