Messages in this thread | | | From | "H. Peter Anvin" <> | Date | Mon, 30 Apr 2001 00:29:35 -0700 | Subject | Re: X15 alpha release: as fast as TUX but in user space (fwd) |
| |
"David S. Miller" wrote: > > dean gaudet writes: > > i was kind of solving a different problem with the code page though -- the > > ability to use rdtsc on SMP boxes with processors of varying speeds and > > synchronizations. > > A better way to solve that problem is the way UltraSPARC-III do and > future ia64 systems will, by way of a "system tick" register which > increments at a constant rate regardless of how the cpus are clocked. > > The "system tick" pulse goes into the processor, so it's still a local > cpu register being accessed. Think of it as a system bus clock cycle > counter. > > Granted, you probably couldn't make changes to the hardware you were > working on at the time :-) >
RDTSC in Crusoe processors does basically this.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt - 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/
| |