Re: [PATCH v4 14/25] perf stat: Add default hybrid events

[Jin, Yao]

Hi Jiri,

On 4/22/2021 2:29 AM, Jiri Olsa wrote:
> On Fri, Apr 16, 2021 at 10:05:06PM +0800, Jin Yao wrote:
>
> SNIP
>
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index 1255af4751c2..0351b99d17a7 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -1145,6 +1145,13 @@ static int parse_stat_cgroups(const struct option *opt,
> >   	return parse_cgroups(opt, str, unset);
> >   }
> >   
> > +static int add_default_hybrid_events(struct evlist *evlist)
> > +{
> > +	struct parse_events_error err;
> > +
> > +	return parse_events(evlist, "cycles,instructions,branches,branch-misses", &err);
> > +}
> > +
> >   static struct option stat_options[] = {
> >   	OPT_BOOLEAN('T', "transaction", &transaction_run,
> >   		    "hardware transaction statistics"),
> > @@ -1626,6 +1633,12 @@ static int add_default_attributes(void)
> >     { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS	},
> >     { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES		},
> >   
> > +};
> > +	struct perf_event_attr default_sw_attrs[] = {
> > +  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK		},
> > +  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES	},
> > +  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS		},
> > +  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS		},
>
> hum, why not use default_attrs0, it's the same, no?

The default_attrs0 has one more item " {.type = PERF_TYPE_HARDWARE, .config = 
PERF_COUNT_HW_CPU_CYCLES },"

So I have to only pick out the sw attrs and save them to default_sw_attrs.

> >   };
> >   
> >   /*
> > @@ -1863,6 +1876,14 @@ static int add_default_attributes(void)
> >   	}
> >   
> >   	if (!evsel_list->core.nr_entries) {
> > +		if (perf_pmu__has_hybrid()) {
> > +			if (evlist__add_default_attrs(evsel_list,
> > +						      default_sw_attrs) < 0) {
> > +				return -1;
> > +			}
> > +			return add_default_hybrid_events(evsel_list);
>
> please do it the same way like when topdown calls parse events,
> we don't need to check for cycles, but please check result and
> display the error

Something like this?

err = parse_events(evsel_list, "cycles,instructions,branches,branch-misses", &errinfo);
if (err) {
	fprintf(stderr,...);
	parse_events_print_error(&errinfo, ...);
	return -1;
}

> > +		}
> > +
> >   		if (target__has_cpu(&target))
> >   			default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK;
>
> also you still want this change for hybrid pmus as well

Yes, the default_sw_attr only uses 'PERF_COUNT_SW_TASK_CLOCK', we do need to change it to 
PERF_COUNT_SW_CPU_CLOCK for system wide.

> thanks,
> jirka

Thanks
Jin Yao

> >   
> > --
> > 2.17.1