> I have tried it for measuring number of instructions. But I am in doubt > that instructions is a correct counter for performance measurement as > different instructions may have very different execution times depending > on many reasons, like cache misses and current memory traffic. I have > tried to use tsc to count CPU cycles, but got the error: > # pmcstat -n 10000 -S "tsc" -O sample.out > pmcstat: ERROR: Cannot allocate system-mode pmc with specification > "tsc": Operation not supported > What have I missed?
You cannot sample with the TSC since the TSC does not interrupt the CPU. For CPU cycles you would probably want to use "p4-global-power-events"; see pmc(3). Regards, Koshy _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "[EMAIL PROTECTED]"
