* libperf : Can not create event group
@ 2021-06-14 7:17 nakamura.shun
2021-06-14 11:17 ` Jiri Olsa
0 siblings, 1 reply; 5+ messages in thread
From: nakamura.shun @ 2021-06-14 7:17 UTC (permalink / raw)
To: peterz, mingo, acme, mark.rutland, alexander.shishkin, jolsa, namhyung
Cc: linux-perf-users, linux-kernel
Hello.
perf_evsel__open cannot create an event group because it set group_fd
to -1 when it ran perf_event_open.
Is there any reason why group_fd is fixed at -1?
Best Regards
Shunsuke
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libperf : Can not create event group
2021-06-14 7:17 libperf : Can not create event group nakamura.shun
@ 2021-06-14 11:17 ` Jiri Olsa
2021-06-22 7:57 ` nakamura.shun
0 siblings, 1 reply; 5+ messages in thread
From: Jiri Olsa @ 2021-06-14 11:17 UTC (permalink / raw)
To: nakamura.shun
Cc: peterz, mingo, acme, mark.rutland, alexander.shishkin, namhyung,
linux-perf-users, linux-kernel
On Mon, Jun 14, 2021 at 07:17:53AM +0000, nakamura.shun@fujitsu.com wrote:
> Hello.
>
> perf_evsel__open cannot create an event group because it set group_fd
> to -1 when it ran perf_event_open.
> Is there any reason why group_fd is fixed at -1?
hi,
there'no leader link on this level yet (in struct evsel)
so this is not implemented at the moment
jirka
>
> Best Regards
> Shunsuke
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libperf : Can not create event group
2021-06-14 11:17 ` Jiri Olsa
@ 2021-06-22 7:57 ` nakamura.shun
2021-06-22 21:06 ` Jiri Olsa
0 siblings, 1 reply; 5+ messages in thread
From: nakamura.shun @ 2021-06-22 7:57 UTC (permalink / raw)
To: Jiri Olsa
Cc: peterz, mingo, acme, mark.rutland, alexander.shishkin, namhyung,
linux-perf-users, linux-kernel
Hi, jirka
> there'no leader link on this level yet (in struct evsel)
> so this is not implemented at the moment
Thanks for the info.
Do you have any plans to support the event group in libperf?
Best Regards
Shunsuke
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libperf : Can not create event group
2021-06-22 7:57 ` nakamura.shun
@ 2021-06-22 21:06 ` Jiri Olsa
2021-06-28 8:44 ` nakamura.shun
0 siblings, 1 reply; 5+ messages in thread
From: Jiri Olsa @ 2021-06-22 21:06 UTC (permalink / raw)
To: nakamura.shun
Cc: peterz, mingo, acme, mark.rutland, alexander.shishkin, namhyung,
linux-perf-users, linux-kernel
On Tue, Jun 22, 2021 at 07:57:56AM +0000, nakamura.shun@fujitsu.com wrote:
> Hi, jirka
>
> > there'no leader link on this level yet (in struct evsel)
> > so this is not implemented at the moment
>
> Thanks for the info.
>
> Do you have any plans to support the event group in libperf?
hi,
not until now I guess ;-) what's your use case?
jirka
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libperf : Can not create event group
2021-06-22 21:06 ` Jiri Olsa
@ 2021-06-28 8:44 ` nakamura.shun
0 siblings, 0 replies; 5+ messages in thread
From: nakamura.shun @ 2021-06-28 8:44 UTC (permalink / raw)
To: Jiri Olsa
Cc: peterz, mingo, acme, mark.rutland, alexander.shishkin, namhyung,
linux-perf-users, linux-kernel
Hi, jirka
> > Do you have any plans to support the event group in libperf?
>
> hi,
> not until now I guess ;-) what's your use case?
PAPI uses event group to measure multiple events.
libperf uses multiplexing regardless of the user's intent.
I thought it would be nice if users could choose to use multiplexing or event groups.
Best Regards
Shunsuke
jirka
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-06-28 8:52 UTC | newest]
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2021-06-14 7:17 libperf : Can not create event group nakamura.shun
2021-06-14 11:17 ` Jiri Olsa
2021-06-22 7:57 ` nakamura.shun
2021-06-22 21:06 ` Jiri Olsa
2021-06-28 8:44 ` nakamura.shun
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