From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Andrew Steets <asteets@rgmadvisors.com>
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect
Date: Fri, 27 Jan 2012 22:34:23 +0100 [thread overview]
Message-ID: <1327700063.2446.178.camel@twins> (raw)
In-Reply-To: <4F2303D8.80300@rgmadvisors.com>
On Fri, 2012-01-27 at 14:06 -0600, Andrew Steets wrote:
> On 1/27/12 11:12 AM, Peter Zijlstra wrote:
> > On Fri, 2012-01-27 at 11:03 -0600, Andrew Steets wrote:
> >> Can anyone tell
> >> me if I'm using this wrong or if this is a bug?
> >
> > You're using it wrong, it will disable events you own (created) not
> > events that monitor you.
>
> Is there an alternate way of disabling events that monitor the current
> process?
Nope, nor will there ever be.
> I ask because I came across the following description in
> tools/perf/design.txt:
>
> A process can enable or disable all the counter groups that are
> attached to it, using prctl:
>
> prctl(PR_TASK_PERF_EVENTS_ENABLE);
>
> prctl(PR_TASK_PERF_EVENTS_DISABLE);
>
> This applies to all counters on the current process, whether created
> by this process or by another, and doesn't affect any counters that
> this process has created on other processes. It only enables or
> disables the group leaders, not any other members in the groups.
That's wrong.. also I wouldn't ever allow such a 'feature', that's just
asking for trouble.
next prev parent reply other threads:[~2012-01-27 21:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-27 17:03 perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect Andrew Steets
2012-01-27 17:12 ` Peter Zijlstra
2012-01-27 20:06 ` Andrew Steets
2012-01-27 21:34 ` Peter Zijlstra [this message]
2012-01-28 12:01 ` Ingo Molnar
2012-01-28 23:48 ` Andrew Steets
2012-01-29 16:32 ` Ingo Molnar
2012-01-29 17:50 ` Gleb Natapov
2012-01-30 9:52 ` Peter Zijlstra
2012-01-30 10:11 ` Ingo Molnar
2012-01-30 11:01 ` Peter Zijlstra
2012-01-30 11:31 ` Ingo Molnar
2012-01-30 13:45 ` Peter Zijlstra
2012-01-30 13:58 ` Ingo Molnar
2012-01-30 15:30 ` Arnaldo Carvalho de Melo
2012-01-30 15:29 ` Arnaldo Carvalho de Melo
2012-02-01 19:03 ` Frederic Weisbecker
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