fix: fix bug in perf module

[Rouzip]

Fix: #3360

1. Fix ioctl enable flag since we use perf group context
2. Group leader and other events use same pid(cgroup fd).

[k8s-ci-robot]

Hi @Rouzip. Thanks for your PR.

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[Rouzip]

Any ideas and comment is welcome😀 @iwankgb

[iwankgb]

@Rouzip have you come across an issue with perf in cAdvisor?

[iwankgb]

/ok-to-test

[Rouzip]

@Rouzip have you come across an issue with perf in cAdvisor?

Sorry for the late response. I am developing a similar tool like cAdvisor perf module. In this document, it says:

pid == -1 and cpu >= 0
This measures all processes/threads on the specified CPU.
This requires CAP_PERFMON (since Linux 5.8) or
CAP_SYS_ADMIN capability or a
/proc/sys/kernel/perf_event_paranoid value of less than 1.

PERF_EVENT_IOC_ENABLE
This enables the individual event or event group specified
by the file descriptor argument.
If the PERF_IOC_FLAG_GROUP bit is set in the ioctl
argument, then all events in a group are enabled, even if
the event specified is not the group leader (but see
BUGS).

So I think we need to change it in cAdvisor.

[Rouzip]

hello, anything I can do there? @iwankgb