Re: [PATCH v5 2/6] perf record: Get the first sample time and last sample time

[Jin, Yao]

On 10/23/2017 11:04 PM, Jiri Olsa wrote:
> On Sat, Oct 21, 2017 at 07:27:50AM +0800, Jin Yao wrote:
> > In perf record, it's walked on all samples yet. So it's very easy to get
> > the first/last samples and save the time to perf file header via the
> > function write_sample_time().
> >
> > In later, perf report/script will fetch the time from perf file header.
> >
> > Change log:
> > -----------
> > v5: There is an issue that the sample walking can only work when
> >      '--buildid-all' is not enabled. So we need to let the walking
> >      be able to work even if '--buildid-all' is enabled and let the
> >      processing skips the dso hit marking for this case.
> >
> >      At first, I want to provide a new option "--record-time-boundaries".
> >      While after consideration, I think a new option is not very
> >      necessary.
> >
> > v3: Remove the definitions of first_sample_time and last_sample_time
> >      from struct record and directly save them in perf_evlist.
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/builtin-record.c | 20 ++++++++++++--------
> >   1 file changed, 12 insertions(+), 8 deletions(-)
> >
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index a6cbf16..bd711e8 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -391,8 +391,19 @@ static int process_sample_event(struct perf_tool *tool,
> >   {
> >   	struct record *rec = container_of(tool, struct record, tool);
> >   
> > -	rec->samples++;
> > +	if (rec->evlist->first_sample_time == 0)
> > +		rec->evlist->first_sample_time = sample->time;
> > +
> > +	rec->evlist->last_sample_time = sample->time;
> > +
> > +	/*
> > +	 * If --buildid-all is given, it marks all DSO regardless of hits,
> > +	 * so no need to process this sample.
> > +	 */
> > +	if (rec->buildid_all)
> > +		return 0;
> >   
> > +	rec->samples++;
> >   	return build_id__mark_dso_hit(tool, event, sample, evsel, machine);
> >   }
> >   
> > @@ -415,13 +426,6 @@ static int process_buildids(struct record *rec)
> >   	 */
> >   	symbol_conf.ignore_vmlinux_buildid = true;
> >   
> > -	/*
> > -	 * If --buildid-all is given, it marks all DSO regardless of hits,
> > -	 * so no need to process samples.
> > -	 */
> > -	if (rec->buildid_all)
> > -		rec->tool.sample = NULL;
>
> hum, could you still unset the sample if there's no time given?
> and keep the speed in this case..
>
> jirka

Oh, yes, I should do that. Thanks Jiri!

Hi Arnaldo, do you have any comment for v5?

I will prepare v6 for adding fixes according to all comments.

Thanks
Jin Yao