[PATCH V3 0/6] Generalise ARM perf-events backend for oprofile

Ingo Molnar mingo at elte.hu
Mon Sep 13 04:51:37 EDT 2010


* Matt Fleming <matt at console-pimps.org> wrote:

> On Mon, Sep 13, 2010 at 09:13:32AM +0200, Marc Titinger wrote:
> > 
> > Hi, 
> > 
> > I'm just being curious : do these patches change the way those chips 
> > should be supported, that do not have a PMU-like IP, but implement 
> > PC-sampling thanks to a general purpose timer (not the system timer) 
> > ?
> 
> CPUs that do not have a PMU are not required to use the perf-events 
> oprofile backend, it is entirely optional. The pc-sampling timer in 
> oprofile is not affected by this series.

It should still work fine though: a generalized oprofile backend should 
simply use hrtimer based events. That also has a chance to be higher 
quality than the system time fallback, on PMU-less (but high-res-timer 
capable) systems.

Thanks,

	Ingo



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