> > > Unfortunately it turns out that nanoTime drifts quite badly relative > to currentTimeMillis, so currentTimeMillis has to be used to anchor > that drift. > Otherwise the times just don't add up properly. > > The JMeter property "sampleresult.useNanoTime" can be set to "false" > to disable the use of nanoTime.
Right, if nanoTime in Windows uses a TSC I would expect drift especially on newer processors. Not all cores receive all clocks and since the value in the TSC * CPu frequency is the current time, not having an accurate count of clocks would cause drift. currentTimeMillis relying on a RTC would have smaller amounts of drift which would only be noticed between machines (which would be correct with NTP). So your correction of drift would be consistent with this. On Solaris, the drift between the TOD clock and the TSC is correct after a 1ms drift 125us at a time. I think MS has attempted something similar (due to complaints from gamers) but I'm not aware of the details. Regards, Kirk --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
