Re: IPI Benchmark Data?
Matthew Dillon <[email protected]> Wed, 3 Aug 2016 09:29:24 -0700
| Newsgroups | gmane.os.dragonfly-bsd.kernel |
|---|---|
| Message-ID | <CAOZ7CpA3qmx04De8Z+tH13kSrNu1G3hese82b8R5V=EWZ18-aA@mail.gmail.com> |
I have some saved output from ./ipitest script runs that I've run on various cpus: http://apollo.backplane.com/DFlyMisc/ipitest01.txt http://apollo.backplane.com/DFlyMisc/ipitest02.txt http://apollo.backplane.com/DFlyMisc/ipitest03.txt http://apollo.backplane.com/DFlyMisc/ipitest04.txt http://apollo.backplane.com/DFlyMisc/ipitest05.txt The numbers are in nanoseconds, so e.g. '2900' would be 2.9uS. '29000' would be 29uS. The originating cpu is #0. As an example, taking ipitest05.txt, due to the topological layout cpu #16 is the co-thread for cpu #0 and one can see it in the numbers (since cpu #0 is initiating the test, it's generally not running in a low-power mode regardless of the C state we use). The results generally follow expectations. A cpu sitting in a deep C state can take over 30uS to respond. Minimum IPI latency is usually in the 1-2uS range. -Matt