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

Jin, Yao
2021-01-21T05:14:28Z

Hi Jiri,

On 1/21/2021 5:25 AM, Jiri Olsa wrote:
> On Mon, Jan 18, 2021 at 12:54:37PM +0800, Jin, Yao wrote:
>> 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.
>
> hm, originaly there's no purpose for the '+', right?
> it seems it's more like bug then anything else
>

Yes, I also don't understand what's the purpose for the '+'. Just a bug is possible.

> you added function to the '+' to add default events to specified event,
> which I think is good idea, but I don't think we should display the
> extra '+' in output
>

I'm OK to remove the extra '+' in output.

Thanks
Jin Yao

> thanks,
> jirka
>