Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect

From: Ingo Molnar
Date: Sun Jan 29 2012 - 11:32:45 EST



* Andrew Steets <asteets@xxxxxxxxxxxxxxx> wrote:

> On 1/28/12 6:01 AM, Ingo Molnar wrote:
>
> >> prctl(PR_TASK_PERF_EVENTS_DISABLE) doesn't appear to
> >> disable perf event counters. Here is a demonstration
> >> program:
> >
> > btw., what's your usecase?
>
> I'm trying to profile a small section of a long-running
> program. I ran into trouble using call-graph recording and I
> thought this might be an alternative way of getting what I was
> after.

That usecase indeed makes sense. Peter, could we allow this for
privileged tasks, depending on the perf_paranoia settings or
such?

Thanks,

Ingo
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