Re: [PATCH v2] perf stat: Append to default list if use -e +event

Jin, Yao
2021-01-18T04:56:47Z

Hi Jiri,

On 1/12/2021 6:08 PM, Jiri Olsa wrote:
> On Mon, Jan 04, 2021 at 10:18:37AM +0800, Jin Yao wrote:
>> The default event list includes the most common events which are widely
>> used by users. But with -e option, the current perf only counts the events
>> assigned by -e option. Users may want to collect some extra events with
>> the default list. For this case, users have to manually add all the events
>> from the default list. It's inconvenient. Also, users may don't know how to
>> get the default list.
>>
>> Now it supports a simple syntax: -e +event
>>
>> The prefix '+' tells perf to append this event (or event list) to default
>> event list.
>>
>> Before:
>>
>> root@kbl-ppc:~# ./perf stat -e power/energy-pkg/ -a -- sleep 1
>>
>> Performance counter stats for 'system wide':
>>
>> 2.04 Joules power/energy-pkg/
>>
>> 1.000863884 seconds time elapsed
>>
>> After:
>>
>> root@kbl-ppc:~# ./perf stat -e +power/energy-pkg/ -a -- sleep 1
>>
>> Performance counter stats for 'system wide':
>>
>> 2.11 Joules +power/energy-pkg/ # 0.000 K/sec
>
> I dont think we should print the extra '+' prefix
>
> jirka
>
>> 8,007.17 msec cpu-clock # 7.993 CPUs utilized
>> 125 context-switches # 0.016 K/sec
>> 8 cpu-migrations # 0.001 K/sec
>> 2 page-faults # 0.000 K/sec
>> 8,520,084 cycles # 0.001 GHz
>> 2,808,302 instructions # 0.33 insn per cycle
>> 555,427 branches # 0.069 M/sec
>> 59,005 branch-misses # 10.62% of all branches
>>
>> 1.001832003 seconds time elapsed
>>
>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>

Printing '+' prefix is the original behavior.

Without this patch,

root@kbl-ppc:# ./perf stat -e +power/energy-pkg/ -a -- sleep 1

Performance counter stats for 'system wide':

2.02 Joules +power/energy-pkg/

1.000859434 seconds time elapsed

The '+' prefix is printed. So I finally decide not to remove the '+' prefix in order to keep
original behavior.

Thanks
Jin Yao