Re: [drm/i915/gt] 8c3b1ba0e7: perf-sanity-tests.Parse_event_definition_strings.fail

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Feb 26, 2021 at 08:41:26AM +0800, Jin, Yao wrote:

SNIP

> > +				SET_SYMBOL(prefix, PMU_EVENT_SYMBOL);
> >   				len++;
> >   			}
> >   		}
> >   	}
> > +
> > +	/* unlikely, but still.. */
> > +	if (!len)
> > +		goto err;
> > +	perf_pmu_events_list_num = len;
> > +
> >   	qsort(perf_pmu_events_list, len,
> >   		sizeof(struct perf_pmu_event_symbol), comp_pmu);
> > 
> 
> Thanks so much for the patch! It works with my tests.
> 
> # ./perf test 6
>  6: Parse event definition strings                                  : Ok
> 
> # ./perf stat -e software/r1a/ -a -- sleep 1
> 
>  Performance counter stats for 'system wide':
> 
>    <not supported>      software/r1a/
> 
>        1.000940433 seconds time elapsed
> 
> In theory, do we also need to check suffix as well? I think returning
> PMU_EVENT_SYMBOL_SUFFIX may also confuse the parser. But yes, we don't have
> this case now.

yep, let's wait for use case ;-) you can't have suffix
without prefix, and that's the one failing, so I think
we are fine

thanks,
jirka