From: Paul Mackerras <paulus@samba.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: eranian@gmail.com, Ingo Molnar <mingo@elte.hu>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Robert Richter <robert.richter@amd.com>,
Andi Kleen <andi@firstfloor.org>,
Maynard Johnson <mpjohn@us.ibm.com>, Carl Love <cel@us.ibm.com>,
Corey J Ashford <cjashfor@us.ibm.com>,
Philip Mucci <mucci@eecs.utk.edu>,
Dan Terpstra <terpstra@eecs.utk.edu>,
perfmon2-devel <perfmon2-devel@lists.sourceforge.net>
Subject: Re: perf_counters issue with enable_on_exec
Date: Tue, 25 Aug 2009 08:27:56 +1000 [thread overview]
Message-ID: <19091.5100.328432.510132@cargo.ozlabs.ibm.com> (raw)
In-Reply-To: <1251121618.7538.262.camel@twins>
Peter Zijlstra writes:
> 2. enable_on_exec only works on leaders, Paul, was that intended?
I think I thought that would be sufficient, but I guess it would be
cleaner if it also worked on non-leaders.
> 3. the scale stuff seems broken
>
> # perf stat -e cycles -e instructions --repeat 10 true
>
> Performance counter stats for 'true' (10 runs):
>
> 2612124 cycles ( +- 1.327% )
> 1870479 instructions # 0.716 IPC ( +- 0.132% )
>
> 0.003743155 seconds time elapsed ( +- 1.203% )
>
> # ./test-enable_on_exec true
> 2651600 PERF_COUNT_HW_CPU_CYCLES 1111509 1111509 2651600.000000
> 1832720 PERF_COUNT_HW_INSTRUCTIONS 839395242 1111509 1384043177.264637
>
> Paul, would a counter's time start running when its 'enabled' but part
> of a non-runnable group?
No, it shouldn't. If it does it's a bug.
Paul.
next prev parent reply other threads:[~2009-08-24 22:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-20 13:49 perf_counters issue with enable_on_exec stephane eranian
2009-08-24 13:46 ` Peter Zijlstra
2009-08-24 15:44 ` stephane eranian
2009-08-24 16:03 ` stephane eranian
2009-08-24 16:06 ` Peter Zijlstra
2009-08-24 16:16 ` stephane eranian
2009-08-24 22:31 ` Paul Mackerras
2009-08-25 5:17 ` [PATCH] perf_counter: Start counting time enabled when group leader gets enabled Paul Mackerras
2009-08-25 7:21 ` Peter Zijlstra
2009-08-25 7:36 ` [tip:perfcounters/core] " tip-bot for Paul Mackerras
2009-08-24 22:27 ` Paul Mackerras [this message]
2009-08-24 21:35 ` perf_counters issue with enable_on_exec Paul Mackerras
2009-08-24 22:30 ` stephane eranian
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