Messages in this thread | | | Date | Thu, 1 Jul 2010 16:31:12 +0100 | From | MattFleming <> | Subject | Re: [RFC][PATCH 00/11] perf pmu interface -v2 |
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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.
> 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.
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