Messages in this thread | | | Subject | Re: How do i read the clock cycle counter? | From | Paul Flinders <> | Date | 27 Apr 1998 21:17:43 +0100 |
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Thomas Jensen <kauf@cs.auc.dk> writes:
> Hi! > > I'm using Linux RedHat 5.0 (Kernel 2.0.33), and i have to do some time > measurements. How do i read the clock cycle counter register in a > pentium / Pentium II CPU ?? > > Thomas Kaufmann Jensen / kauf@cs.auc.dk > > . > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu
unsigned int count[2]; asm("rdtsc" :"=a" (count[0]), "=d" (count[1]));
Should do it, you need a gas recent enough to understabd the rdtsc opcode. If not there's an example somewhere in the kernel code which uses the opcodes.
-- Paul
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