Messages in this thread |  | | | Date | Fri, 27 May 2011 23:38:30 -0400 (EDT) | | From | Vince Weaver <> | | Subject | Re: perf: regression with PERF_EVENT_IOC_REFRESH |
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On Tue, 24 May 2011, Peter Zijlstra wrote: > > This is very clear abuse of the API and I'm not really inclined to fix > it, in fact, I'd be tempted to add an additional test to verify the > argument to REFRESH > 0.
on that note (and while trying to document exactly what the ioctls do) it seems that a PERF_EVENT_IOC_REFRESH with an argument of anything higher than one does not work on kernels 2.6.36 and newer. The behavior acts as if 1 was passed, even if you pass in, say, 3.
Is it worth bisecting this, or has this become the new official behavior since no one noticed until now?
To reproduce you can grab my tests from here: http://web.eecs.utk.edu/~vweaver1/projects/perf-events/validation.html
and run the ./validation/simple_overflow_leader test
Vince
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