Re: [PATCH] Turn rdmsr, rdtsc into inline functions, clarify names
From: Vojtech Pavlik
Date: Mon Aug 07 2006 - 07:07:35 EST
On Mon, Aug 07, 2006 at 10:48:50AM +0200, Andi Kleen wrote:
> On Sun, Aug 06, 2006 at 10:43:44PM -0400, Dmitry Torokhov wrote:
> > On Saturday 05 August 2006 23:16, Andi Kleen wrote:
> > > This whole thing is broken, e.g. on a preemptive kernel when the
> > > code can switch CPUs
> > >
> > Would not preempt_disable fix that?
> Partially, but you still have other problems. Please just get rid
> of it. Why do we have timer code in the kernel if you then chose
> not to use it?
The problem is that gettimeofday() is not always fast. The joystick
drivers will not work if the timing calls take significant time compared
to an inb() from ISA/LPC space.
That's why they don't fallback to PIT timing when TSC is not available -
io counting is a better option.
Director SuSE Labs
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/