Messages in this thread |  | | Date | Thu, 8 Nov 2001 22:22:36 +0100 | From | Vojtech Pavlik <> | Subject | Re: VIA 686 timer bugfix incomplete |
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On Thu, Nov 08, 2001 at 10:17:51PM +0100, Jonas Diemer wrote:
> On Thu, 8 Nov 2001 21:08:40 +0100 > Vojtech Pavlik <vojtech@suse.cz> wrote: > > > There is a little problem with RTC, though: > > > > While you can set it up to generate interrupts at say 1024 Hz, you can't > > read any value of how much time passed since last interrupt. You can do > > this on the PIT (i8253), and this is the part that is buggy. > > > > TSC is perfect, precise and accurate, but not reliable in long term. > > Some CPUs do thermal throttling, notebooks play with CPU speed, etc, > > etc. And it's not synchronized to any interrupt source. > > > > Ugly, ugly, ugly is the PC architecture. > > > > can't you just read the battery buffered clock? how are other OSes such as > Window$ doing the timing?
You can. But you only get 0.5 second resolution, which obviously isn't good enough for microsecond timing.
-- Vojtech Pavlik SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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