From: Peter Zijlstra <peterz@infradead.org>
To: Matt Fleming <matt@console-pimps.org>
Cc: Will Deacon <will.deacon@arm.com>, paulus <paulus@samba.org>,
stephane eranian <eranian@googlemail.com>,
Robert Richter <robert.richter@amd.com>,
Paul Mundt <lethal@linux-sh.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Lin Ming <ming.m.lin@intel.com>,
Yanmin <yanmin_zhang@linux.intel.com>,
Deng-Cheng Zhu <dengcheng.zhu@gmail.com>,
David Miller <davem@davemloft.net>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH 00/11] perf pmu interface -v2
Date: Thu, 01 Jul 2010 17:39:53 +0200 [thread overview]
Message-ID: <1277998793.1917.212.camel@laptop> (raw)
In-Reply-To: <20100701153112.GA13511@console-pimps.org>
On Thu, 2010-07-01 at 16:31 +0100, MattFleming wrote:
> On Thu, Jul 01, 2010 at 05:02:35PM +0200, Peter Zijlstra wrote:
> >
> > Matt, you said it broke SH completely, but did you try perf stat? perf
> > record is not supposed to work on SH due to the hardware not having an
> > overflow interrupt.
>
> perf record does work to some degree. It definitely worked before
> applying your changes but not after. I admit I haven't really read the
> perf event code, but Paul will know.
Ok, let me look at that again.
> > Which made me think, what on SH guarantees we update the counter often
> > enough not to suffer from counter wrap? Would it make sense to make the
> > SH code hook into their arch tick handler and update the counters from
> > there?
>
> This was the way that the oprofile code used to work. Paul and I were
> talking about using a hrtimer to sample performance counters as
> opposed to piggy-backing on the tick handler.
Ah, for sampling for sure, simply group a software perf event and a
hardware perf event together and use PERF_SAMPLE_READ.
But suppose its a non sampling counter, how do you avoid overflows of
the hardware register?
next prev parent reply other threads:[~2010-07-01 15:40 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-24 14:28 [RFC][PATCH 00/11] perf pmu interface -v2 Peter Zijlstra
2010-06-24 14:28 ` [PATCH 01/11] perf, x86: Fix Nehalem PMU quirk Peter Zijlstra
2010-06-24 14:28 ` [PATCH 02/11] perf: Fix argument of perf_arch_fetch_caller_regs Peter Zijlstra
2010-06-24 14:28 ` [PATCH 03/11] perf, sparc64: Fix maybe_change_configuration() PCR setting Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 04/11] perf: deconstify struct pmu Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 05/11] perf: register pmu implementations Peter Zijlstra
2010-06-28 13:21 ` Frederic Weisbecker
2010-06-28 15:16 ` Peter Zijlstra
2010-06-28 15:29 ` Frederic Weisbecker
2010-07-09 3:08 ` Paul Mackerras
2010-07-09 8:14 ` Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 06/11] perf: Unindent labels Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 07/11] perf: Reduce perf_disable() usage Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 08/11] perf: Per PMU disable Peter Zijlstra
2010-07-09 7:31 ` Paul Mackerras
2010-07-09 8:36 ` Peter Zijlstra
2010-06-24 14:28 ` [RFC][PATCH 09/11] perf: Default PMU ops Peter Zijlstra
2010-06-29 14:49 ` Frederic Weisbecker
2010-06-29 14:57 ` Peter Zijlstra
2010-06-29 15:00 ` Frederic Weisbecker
2010-06-29 14:58 ` Frederic Weisbecker
2010-06-29 14:59 ` Peter Zijlstra
2010-06-29 15:03 ` Frederic Weisbecker
2010-06-29 16:34 ` Peter Zijlstra
2010-06-29 18:07 ` Frederic Weisbecker
2010-06-29 18:09 ` Peter Zijlstra
2010-06-29 18:11 ` Frederic Weisbecker
2010-06-29 18:19 ` Peter Zijlstra
2010-06-29 18:21 ` Frederic Weisbecker
2010-06-24 14:28 ` [RFC][PATCH 10/11] perf: Shrink hw_perf_event Peter Zijlstra
2010-06-29 15:06 ` Frederic Weisbecker
2010-06-24 14:28 ` [RFC][PATCH 11/11] perf: Rework the PMU methods Peter Zijlstra
2010-06-29 15:37 ` Frederic Weisbecker
2010-06-29 16:40 ` Peter Zijlstra
2010-06-29 18:09 ` Frederic Weisbecker
2010-06-25 11:11 ` [RFC][PATCH 00/11] perf pmu interface -v2 Will Deacon
2010-06-25 11:16 ` Peter Zijlstra
2010-06-25 14:36 ` Will Deacon
2010-06-25 14:50 ` Peter Zijlstra
2010-07-01 14:36 ` Peter Zijlstra
2010-07-01 15:02 ` Peter Zijlstra
2010-07-01 15:31 ` MattFleming
2010-07-01 15:39 ` Peter Zijlstra [this message]
2010-07-01 16:04 ` Matt Fleming
2010-07-02 2:57 ` Paul Mundt
2010-07-02 9:52 ` Peter Zijlstra
2010-07-05 11:14 ` Paul Mundt
2010-07-08 11:13 ` Peter Zijlstra
2010-07-08 11:19 ` Ingo Molnar
2010-07-18 19:37 ` Matt Fleming
2010-07-02 12:55 ` Will Deacon
2010-06-26 11:22 ` Matt Fleming
2010-06-26 16:22 ` Corey Ashford
2010-06-28 15:13 ` Peter Zijlstra
2010-06-30 17:19 ` Corey Ashford
2010-06-30 18:11 ` Peter Zijlstra
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