Re: [BUG] perf stat: useless output for raw events with new event parser

[Stephane Eranian <eranian@google.com>]

On Mon, Apr 23, 2012 at 12:48 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, 2012-04-23 at 12:45 +0200, Stephane Eranian wrote:
>> Hi,
>>
>> With the new event parser, one can express raw events field by field:
>>
>> $ perf stat -e cpu/event=0x3c,umask=0x0/,cpu/event=0xc5,umask=0x0/ noploop 1
>>
>> The problem with this is that the output of perf stat becomes useless:
>>
>> $ perf stat -e cpu/event=0x3c,umask=0x0/,cpu/event=0xc5,umask=0x0/ noploop 1
>> noploop for 1 seconds
>>
>>  Performance counter stats for 'noploop 1':
>>
>>         2395038678 pmu
>>             10787 pmu
>>                        ^^^^^^
>>        1.000802603 seconds time elapsed
>
> Yeah, I already complained about that.. Jolsa proposed adding a name=
> parameter so you could explicitly name your events. I think I've seen a
> patch adding that, but can't atm seem to locate it.
>
If the proposed solution is to add a pseudo field called "name", then I don't
see the point of this new parser compared to directly using my libpfm4
library which already allows:

 perf stat -e inst_retired:any,wsm_unc:unc_cycles:u ...
And
 perf record -e instr_retired:period=200000,cpu_clk_unhalted:freq=100 ...

If you have to make up names, you might as well, use the actual PMU
event names, but if you do so, why would you have to bother breaking
down the encoding into fields?