Re: [RFC] New Time of day proposal (updated 9/2/04)

Christoph Lameter
2004-09-07T21:00:08Z

On Tue, 7 Sep 2004, George Anzinger wrote:

> Also, we don't "know" what rate the TSC is actully clocking so we must
> "discover" it at boot time. This process either is inaccurate or slow (I think
> we use ~ 50 ms these days which gives an error of ~10 TSC cycles on a 800MHZ
> box). FWIW the problem here is the sync up with the I/O backplane to find the
> start and ending of the measured time.
>
> I suspect that the IA64 "tells" you what its clock rate is. Right?

Not the CPU itself. There is a special hardware I/O interface called the
PAL/SAL that allows one to retrive that information. Doesnt the BIOS on
i386 allow you to get to that information?