Messages in this thread | | | Date | Fri, 21 Jan 2000 15:18:28 -0800 (PST) | From | Jeremy Fitzhardinge <> | Subject | Re: Udelay and new CPUs |
| |
On 21-Jan-00 H. Peter Anvin wrote: > Jeremy Fitzhardinge wrote: >> >> On 21-Jan-00 H. Peter Anvin wrote: >> > There are no "x86 cycles" on Crusoe, so it counts VLIW cycles. In >> > fact, on TM5400 it counts *nominal* cycles, since the actual cycle >> > length is variable (due to LongRun). >> >> So RDTSC is useless for getting consistent udelay delays. >> > > No, on the contrary. For a 700 MHz TM5400 the TSC will always count at > 700 MHz even if the CPU decides that it currently only needs to run at, > say, 175 MHz.
Apparently if you *emphasize* words, they become invisible to my eyes. Sigh, maybe I should start reading with my lips moving...
J
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |