Re: [PATCH] Turn rdmsr, rdtsc into inline functions, clarify names
From: Vojtech Pavlik
Date: Mon Aug 07 2006 - 15:20:27 EST
On Mon, Aug 07, 2006 at 06:12:03PM +0200, Andi Kleen wrote:
> Vojtech Pavlik <vojtech@xxxxxxx> writes:
> > On Mon, Aug 07, 2006 at 05:57:14PM +0200, Andi Kleen wrote:
> > > > That way a driver could use
> > > >
> > > > if (gtod_cpu_cycles_needed <= 500)
> > > > gettimeofday();
> > > > else
> > > > funky_fast_workaround();
> > >
> > > Sounds like overengineering to me. I prefer something simple.
> > I could as well benchmark gettimeofday() in the gameport init.
> Except you can't because the only way to benchmark it would
> be to use gettimeofday already and then you don't know
> how much is overhead and what is the real time.
I run it for 1/10th of a second in a loop and see how many iterations
I've done. That's enough to check if its fast enough to use in the
gameport routine. Less than 50k iterations and I can't use it.
Director SuSE Labs
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