Quoting r. Shirley Ma <[EMAIL PROTECTED]>: > Subject: Re: cycles_to_units is incorrect in rdma_lat, rdma_bw. > > > in case someone's firmware is less accurate than HP's. > > Shirley, did the patch to get_clock.c fix the problem? > > Cycles is not equal to the clock rate. If you have a processor with internal > doubling or pipelining or whatever, the clock rate isn't the same.
The name get_cycles was chosen to match linux kernel API. (get_cycles / cpu_mhz) shall return time in microseconds. If it doesnt get_cycles can just be fixed/renamed. Do you see an actual machine where thats not the case? > > Maybe there shall be a separate utility to compare > > get_cycles and gettimeofday results, may be useful for debug. > > > > Anyway, if get_cpu_mhz isnt reliable people can just dump raw > > cycles data and do the math outside the tool. > > Agree if the rdma_lat, and rdma_bw are only used for debugging/regression > testing not for performance measurement. Its just a work-around in case someone has a problem. But no one complained yet. -- MST _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
