thanks Jim. Will contact you if I have further questions, -Vinay
----- Original Message ----- From: Jim Britton <[email protected]> Date: Friday, June 20, 2008 11:28 am Subject: Re: Turbo Mode Support for Solaris To: Vinay Devadas <Vinay.Devadas at Sun.COM> Cc: tesla-dev at opensolaris.org > Hi Vinay, > > To be honest, I have not looked that closely at PowerTop or how it > works > today. I am assuming it is similar to prstat or top. But I hate to > speculate too much, so let me give you an example of what I would like > > to be able to know. > > Frequently industry standard benchmarks require a certain degree of > reproducibility, say within 5% of our submitted result. Turbo Mode > opens up the potential for a much less reproducible run because our > core > clocks are not 100% deterministically controlled. What I would like > PowerTop to enable is the ability tell how much time was spent in > Turbo > Mode, during the course of a benchmark run. I assume this would also > be > interesting to customers looking at what their own systems are up to > as > well. > > Ideally, I would see a big benefit in being able to log frequencies > used > over the course of a run, similar to mpstat's output about > utilization. > Then we can chart the logs over time and see how things are > fluctuating > during our benchmark runs. > > Feel free to let me know if you have any other questions. > > Thanks, > > Jim > > Vinay Devadas wrote: > > Hi Jim, > > > > I just had a question about the bug you reported about Turbo Mode > not being supported on PowerTop. Wanted to clarify what sort of > statistic did you have in mind when you reported the bug. With the > observability provided by intel, I believe we can only say we were in > turbo mode for some time during the last sampling interval. We feel > the average CPU frequency overall the last sampling interval may be a > more useful statistic. Please let us know on what you think. > > > > Thanks, > > Vinay > > > > -- > Jim Britton - Performance Lead - jim.britton at sun.com > X64 Product Development - Sun Microsystems, Inc. > 400 Atrium Drive, USMT01, Somerset, NJ 08873 > 732.302.3864 - F:732.469.4098 >
