Re: [PATCH] perf report: Show zero counters as well in 'perf report --stat'

From: Jiri Olsa
Date: Wed Mar 07 2018 - 10:37:53 EST


On Wed, Mar 07, 2018 at 04:24:30PM +0100, Ingo Molnar wrote:
>
> When recently using 'perf report --stat' it was not clear to me from the output
> whether a particular statistics field (LOST_SAMPLES) was not present, or just
> zero:
>
> fomalhaut:~> perf report --stat
>
> Aggregated stats:
> TOTAL events: 495984
> MMAP events: 85
> COMM events: 3389
> EXIT events: 1605
> THROTTLE events: 2
> UNTHROTTLE events: 2
> FORK events: 3377
> SAMPLE events: 472629
> MMAP2 events: 14753
> FINISHED_ROUND events: 139
> THREAD_MAP events: 1
> CPU_MAP events: 1
> TIME_CONV events: 1
>
> I had to check the output several times to ascertain that I'm not misreading the
> output, that the field didn't change and that I didn't misremember the name. In
> fact I had to look into the perf source to make sure that zero fields are indeed
> not shown.
>
> With the patch applied:
>
> fomalhaut:~> perf report --stat
>
> Aggregated stats:
> TOTAL events: 495984
> MMAP events: 85
> LOST events: 0
> COMM events: 3389
> EXIT events: 1605
> THROTTLE events: 2
> UNTHROTTLE events: 2
> FORK events: 3377
> READ events: 0
> SAMPLE events: 472629
> MMAP2 events: 14753
> AUX events: 0
> ITRACE_START events: 0
> LOST_SAMPLES events: 0
> SWITCH events: 0
> SWITCH_CPU_WIDE events: 0
> NAMESPACES events: 0
> ATTR events: 0
> EVENT_TYPE events: 0
> TRACING_DATA events: 0
> BUILD_ID events: 0
> FINISHED_ROUND events: 139
> ID_INDEX events: 0
> AUXTRACE_INFO events: 0
> AUXTRACE events: 0
> AUXTRACE_ERROR events: 0
> THREAD_MAP events: 1
> CPU_MAP events: 1
> STAT_CONFIG events: 0
> STAT events: 0
> STAT_ROUND events: 0
> EVENT_UPDATE events: 0
> TIME_CONV events: 1
> FEATURE events: 0

ok, it also might be better to read since now the events
appear in the same place, not scattered based on what was
data was collected

jirka