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

Jin, Yao
2017-10-23T17:38:31Z

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@linux.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 will prepare v6 for adding fixes according to all comments.

Thanks
Jin Yao