Re: [GIT PULL||RFC 00/11] perf library and regression testing improvements

Arnaldo Carvalho de Melo
2011-01-04T14:37:14Z

Em Tue, Jan 04, 2011 at 03:33:38PM +0100, Stephane Eranian escreveu:
> No improvement with this patch.

I was guessing you were using it somehow without calling
perf_evsel__alloc_counts, now I guess you're just using what is in
tip/perf/core, no local changes, right?

Next step: there are anonymous structs inside anonymous unions, what
compiler/distro?

- Arnaldo

> On Tue, Jan 4, 2011 at 3:27 PM, Arnaldo Carvalho de Melo
> <acme@infradead.org> wrote:
> > Em Tue, Jan 04, 2011 at 12:19:58PM -0200, Arnaldo Carvalho de Melo escreveu:
> >> Em Tue, Jan 04, 2011 at 03:09:08PM +0100, Stephane Eranian escreveu:
> >> > Arnaldo,
> >> > Looks like what's wrong is not ps but count:
> >> >
> >> > Program received signal SIGSEGV, Segmentation fault.
> >> > [Switching to Thread 0x7f96967fd6e0 (LWP 5156)]
> >> > 0x0000000000412b58 in read_counter_aggr (counter=0x7d4820) at builtin-stat.c:206
> >> > 206                 update_stats(&ps->res_stats[i], count[i]);
> >> > (gdb) print ps
> >> > $1 = (struct perf_stat *) 0x7d48a0
> >> > (gdb) print *ps
> >> > $2 = {res_stats = {{n = 0, mean = 0, M2 = 0}, {n = 0, mean = 0, M2 =
> >> > 0}, {n = 0, mean = 0, M2 = 0}}}
> >> > (gdb) print count
> >> > $3 = (u64 *) 0x12
> >> > (gdb) print *count
> >> > Cannot access memory at address 0x12
> >> > (gdb) print count
> >> > $4 = (u64 *) 0x12
> >>
> >> Count is:
> >>
> >> u64 *count = counter->counts->aggr.values;
> >
> > Can you try with this patch?
> >
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index 02b2d80..7876b11 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -196,12 +196,14 @@ static inline int nsec_counter(struct perf_evsel *evsel)
> >  static int read_counter_aggr(struct perf_evsel *counter)
> >  {
> >        struct perf_stat *ps = counter->priv;
> > -       u64 *count = counter->counts->aggr.values;
> > +       u64 *count;
> >        int i;
> >
> >        if (__perf_evsel__read(counter, cpus->nr, threads->nr, scale) < 0)
> >                return -1;
> >
> > +       count = counter->counts->aggr.values;
> > +
> >        for (i = 0; i < 3; i++)
> >                update_stats(&ps->res_stats[i], count[i]);
> >
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index d337761..26962ea 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -89,8 +89,12 @@ int __perf_evsel__read(struct perf_evsel *evsel,
> >  {
> >        size_t nv = scale ? 3 : 1;
> >        int cpu, thread;
> > -       struct perf_counts_values *aggr = &evsel->counts->aggr, count;
> > +       struct perf_counts_values *aggr, count;
> >
> > +       if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, ncpus) < 0)
> > +               return -ENOMEM;
> > +
> > +       aggr = &evsel->counts->aggr;
> >        aggr->val = 0;
> >
> >        for (cpu = 0; cpu < ncpus; cpu++) {
> >