From: Gleb Natapov <gleb@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Steets <asteets@rgmadvisors.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
Paul Mackerras <paulus@samba.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect
Date: Sun, 29 Jan 2012 19:50:57 +0200 [thread overview]
Message-ID: <20120129175057.GC2938@redhat.com> (raw)
In-Reply-To: <20120129163235.GB23408@elte.hu>
On Sun, Jan 29, 2012 at 05:32:35PM +0100, Ingo Molnar wrote:
>
> * Andrew Steets <asteets@rgmadvisors.com> 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?
>
This sounds useful not only for privileged tasks. Why not make
it event attribute? If user wants PR_TASK_PERF_EVENTS_DISABLE be
respected for an event it can specify special argument like:
perf record -e cycles:n ./a.out
--
Gleb.
next prev parent reply other threads:[~2012-01-29 17:51 UTC|newest]
Thread overview: 30+ 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
2012-01-28 12:01 ` Ingo Molnar
2012-01-28 23:48 ` Andrew Steets
2012-01-29 16:32 ` Ingo Molnar
2012-01-29 16:32 ` Ingo Molnar
2012-01-29 17:50 ` Gleb Natapov [this message]
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
2013-05-30 23:45 ` Using perf and cgroups to profile part of a long-running program Riku Saikkonen
-- strict thread matches above, loose matches on Subject: below --
2012-07-26 10:54 perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect Iegorov Oleg
2012-07-27 7:26 ` Ingo Molnar
2012-07-27 8:00 ` Peter Zijlstra
2012-07-27 8:18 ` Ingo Molnar
2012-07-27 8:29 ` Peter Zijlstra
2012-07-27 11:40 ` Iegorov Oleg
2012-07-27 11:53 ` Ingo Molnar
2012-07-30 20:04 ` Andi Kleen
2012-07-31 5:47 ` Peter Zijlstra
2012-07-31 7:16 ` Ingo Molnar
2012-07-31 19:48 ` Peter Zijlstra
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