Em Tue, Nov 25, 2014 at 10:36:33AM +0100, Jiri Olsa escreveu:
> On Mon, Nov 24, 2014 at 06:35:33PM -0200, Arnaldo Carvalho de Melo wrote:
> > Em Fri, Nov 21, 2014 at 10:31:08AM +0100, Jiri Olsa escreveu:
> > > Replacing __perf_evsel__read_on_cpu function with perf_evsel__read_cb
> > > function. The read_cb callback will be used later for global aggregation
> > > counter values as well.
> >
> > But the changeset makes it look like there are no changes made... Can
> > you elaborate here?
>
> well the patch change the 'read_counter' function to use the
> perf_evsel__read_cb instead of __perf_evsel__read_on_cpu
That part is ok with me, matches what the subject states it does. The
part I thought was out of place is the SNIP part ;-)
> SNIP
This one:
> +static int read_cb(struct perf_evsel *evsel, int cpu, int thread
> __maybe_unused,
> + struct perf_counts_values *count)
> +{
> + switch (aggr_mode) {
> + case AGGR_CORE:
> + case AGGR_SOCKET:
> + case AGGR_NONE:
> + perf_evsel__compute_deltas(evsel, cpu, count);
> + perf_counts_values__scale(count, scale, NULL);
> + evsel->counts->cpu[cpu] = *count;
> + update_shadow_stats(evsel, count->values);
> + break;
> + case AGGR_GLOBAL:
> + default:
> + break;
> + }
> +
> + return 0;
While the original code did a update_shadow_stats(...), the code that replaces
it calls perf_evsel__compute_deltas(), etc in addition to updating the shadow
stats.
Ok, I see, __perf_evsel__read_on_cpu() does that... my bad, will re-read it
with this in mind, but even then, now we have to make sure
perf_evsel__alloc_counts() was called before this, and also the original code
did it for all AGGR_ modes, will check.
- Arnaldo
> > > +
> > > /*
> > > * Read out the results of a single counter:
> > > * aggregate counts across CPUs in system-wide mode
> > > @@ -424,16 +444,11 @@ static int read_counter_aggr(struct perf_evsel
> > > *counter)
> > > */
> > > static int read_counter(struct perf_evsel *counter)
> > > {
> > > - u64 *count;
> > > int cpu;
> > >
> > > for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
> > > - if (__perf_evsel__read_on_cpu(counter, cpu, 0, scale) < 0)
> > > + if (perf_evsel__read_cb(counter, cpu, 0, read_cb))
>
> right here ^^^
>
> > > return -1;
> > > -
> > > - count = counter->counts->cpu[cpu].values;
> > > -
> > > - update_shadow_stats(counter, count);
> > > }
> > >
> > > return 0;
> > > --
> > > 1.9.3
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