Hello I've been using perfmon2 to calculate CPI for various programs. This is fine on Pentium III, Itanium, and Core machines because both a CYCLES and a RETIRED_INSTRUCTIONS performance counter is available.
However, on Pentium 4 there is no CYCLES counter. My question is, can I use the "unique timestamp" field in the results to somehow get cycle count? From what I can tell this is based on the TSC, which I guess can cause problems on SMP machines if the TSCs aren't synchronized. Also, if using this field would be appropriate, is it possible to get added to the header somehow the starting value of the cycle counter? as it is you wouldn't be able to calculate CPI for the first interval because you wouldn't know the starting counter value to subtract. I tried digging through the perfmon code myself to figure this out, but it gets a bit confusing in places. I'll make another attempt at things if it turns out this is a valid way to get the cycle count. Thanks, Vince [EMAIL PROTECTED] _______________________________________________ perfmon mailing list [email protected] http://www.hpl.hp.com/hosted/linux/mail-archives/perfmon/
