libperf : Can not create event group

From: nakamura.shun@xxxxxxxxxxx
Date: Mon Jun 14 2021 - 03:18:01 EST


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