Messages in this thread | | | Date | Fri, 26 Jun 2009 09:23:50 +0200 | From | Ingo Molnar <> | Subject | Re: register_timer_hook use in arch/sh/oprofile |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2009-06-24 at 15:24 +0200, Ingo Molnar wrote: > > > > [ And long-term analysis ('perf stat' type of runs) dont need IRQs > > anyway - perfcounters reads outs the counts and summarizes them > > across the measured workload. ] > > If the counter width is less than 64 bits we do need to have some > interrupt to read them from before they cycle so we can accumulate > the deltas into a proper u64.
Yeah - but even that can be driven from some housekeeping hrtimer.
> But for proper 64 bit hardware counters there is indeed no need > for that.
Indeed - although they are rare.
Ingo
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