Re: [PATCH v2 1/2] perf lock: Correct field name "flags"

From: Leo Yan
Date: Mon Nov 02 2020 - 20:52:28 EST


On Mon, Nov 02, 2020 at 05:42:13PM +0100, Jiri Olsa wrote:
> On Wed, Oct 21, 2020 at 08:39:47AM +0800, Leo Yan wrote:
> > The tracepoint "lock:lock_acquire" contains field "flags" but not
> > "flag". Current code wrongly retrieves value from field "flag" and it
> > always gets zero for the value, thus "perf lock" doesn't report the
> > correct result.
> >
> > This patch replaces the field name "flag" with "flags", so can read out
> > the correct flags for locking.
> >
> > Fixes: 746f16ec6ae3 ("perf lock: Use perf_evsel__intval and perf_session__set_tracepoints_handlers")
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>
> btw it seems the issue was there event before that commit:
> acquire_event.flag = (int)raw_field_value(event, "flag", data);

Thanks for pointing out this, I will change the fix tag as:
Fixes: e4cef1f65061 ("perf lock: Fix state machine to recognize lock sequence")

Leo

> > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> > ---
> > tools/perf/builtin-lock.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> > index f0a1dbacb46c..5cecc1ad78e1 100644
> > --- a/tools/perf/builtin-lock.c
> > +++ b/tools/perf/builtin-lock.c
> > @@ -406,7 +406,7 @@ static int report_lock_acquire_event(struct evsel *evsel,
> > struct lock_seq_stat *seq;
> > const char *name = evsel__strval(evsel, sample, "name");
> > u64 tmp = evsel__intval(evsel, sample, "lockdep_addr");
> > - int flag = evsel__intval(evsel, sample, "flag");
> > + int flag = evsel__intval(evsel, sample, "flags");
> >
> > memcpy(&addr, &tmp, sizeof(void *));
> >
> > --
> > 2.17.1
> >
>