Messages in this thread | | | Date | Fri, 9 Dec 2011 17:22:09 -0500 | From | Vince Weaver <> | Subject | Re: perf_event self-monitoring overhead regression |
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Here are the complete results, using official kernels.
http://web.eecs.utk.edu/~vweaver1/projects/perf-events/benchmarks/rdtsc_overhead/
The overall overhead start/stop/read has been getting worse. 3.1.0 was bad and the current 3.2.0-rc4-tip tree is even worse.
I'm not sure if it's worth trying to track down the changes that cause these regressions, as they might still be considered just noise, though the best to worst performance degredation is ~ 15% when attempting to self-monitor with 3 events on a core2 machine.
Vince
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