On 11/29/18 1:21 PM, Jens Axboe wrote: > On 11/29/18 11:14 AM, vincentfu@xxxxxxxxx wrote: >> From: Vincent Fu <vincent.fu@xxxxxxx> >> >> Since we now have ntime_since() we can use nsec in the division for >> get_cycles_per_msec(). This makes the cycles_per_msec value that fio >> ultimately uses more stable since fio will no longer be using values >> truncated to usec. >> >> While we're here also modify some debug prints to make it explicit that >> fio ultimately uses a trimmed mean in its time calculations. >> >> On platforms where only gettimeofday() is available this will be no >> worse than the original code since we will revert back to using times >> truncated to usec. >> >> With the patch, the last three digits of the trimmed mean have a tight >> range from 784-786. Without the patch, the corresponding value (labeled >> avg) has a much wider range from 821-958. Notice also that the standard >> error S is an order of magnitude smaller with the patch. > This is great, thanks Vincent. Applied. I made a mistake in the commit message. Instead of "a tight range from 784-786" it should be 788-789.
