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

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Date:   Mon, 23 Oct 2017 16:05:50 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     "Jin, Yao" <yao.jin@...ux.intel.com>
Cc:     Jiri Olsa <jolsa@...hat.com>, jolsa@...nel.org,
        peterz@...radead.org, mingo@...hat.com,
        alexander.shishkin@...ux.intel.com, Linux-kernel@...r.kernel.org,
        ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v5 2/6] perf record: Get the first sample time and last
 sample time

Em Tue, Oct 24, 2017 at 01:38:26AM +0800, Jin, Yao escreveu:
> 
> 
> 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@...ux.intel.com>
> > > ---
> > >   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'll try to look at it, but don't that hold v6, I'd say :-\

- Arnaldo
 
> I will prepare v6 for adding fixes according to all comments.
> 
> Thanks
> Jin Yao