Re: [PATCH v3 1/3] perf report: Change sort order by a specified event in group

["Jin, Yao" <yao.jin@linux.intel.com>]

On 12/17/2019 5:06 PM, Jiri Olsa wrote:
> On Tue, Dec 17, 2019 at 09:47:01AM +0800, Jin, Yao wrote:
>>
>>
>> On 12/16/2019 3:31 PM, Jiri Olsa wrote:
>>> On Thu, Dec 12, 2019 at 08:33:35PM +0800, Jin Yao wrote:
>>>
>>> SNIP
>>>
>>>>
>>>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>>>> ---
>>>>    tools/perf/Documentation/perf-report.txt |   4 +
>>>>    tools/perf/builtin-report.c              |  10 +++
>>>>    tools/perf/ui/hist.c                     | 108 +++++++++++++++++++----
>>>>    tools/perf/util/symbol_conf.h            |   1 +
>>>>    4 files changed, 108 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
>>>> index 8dbe2119686a..9ade613ef020 100644
>>>> --- a/tools/perf/Documentation/perf-report.txt
>>>> +++ b/tools/perf/Documentation/perf-report.txt
>>>> @@ -371,6 +371,10 @@ OPTIONS
>>>>    	Show event group information together. It forces group output also
>>>>    	if there are no groups defined in data file.
>>>> +--group-sort-idx::
>>>> +	Sort the output by the event at the index n in group. If n is invalid,
>>>> +	sort by the first event. WARNING: This should be used with --group.
>>>
>>> --group in record or report?
>>>
>>
>> This --group is in perf-report. So even if it's not created with -e '{}' in
>> perf-record, it still supports to show event information together.
>>
>>> you can also create groups with -e '{}', not just --group option
>>>
>>> I wonder you could check early on 'evlist->nr_groups' and fail
>>> if there's no group defined if the option is enabled
>>>
>>
>> Maybe we don't need to check that because it supports the case of no group
>> defined.
>>
>> For example,
>> perf record -e cycles,instructions
>> perf report --group --group-sort-idx 1 --stdio
> 
> hum, --group will force evlist->nr_groups == 1, right?
> 
> so we could warn/fail on (group-sort-idx && !evlist->nr_groups)
> 
> 

Yes, we can. I have added this checking in v4.

> SNIP
> 
>>
>> Thanks. Can we say something as following?
>>
>> --group-sort-idx::
>> 	Sort the output by the event at the index n in group. If n is invalid, sort
>> by the first event. It can support multiple groups with different amount of
>> events. WARNING: This should be used with perf report --group.
> 
> if the events are already grouped you dont need --group ;-) how about:
> 
> 	This should be used on grouped events.
> 

OK, yes, that's better. I just post v4 which includes this update.

Thanks
Jin Yao

> thanks,
> jirka
>