Messages in this thread | | | Date | Sun, 11 Aug 2013 22:39:00 -0300 | From | Karim Yaghmour <> | Subject | Re: Reading perf counters at ftrace trace boundaries |
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On 13-08-11 10:23 PM, Andi Kleen wrote: > KVM does it, see arch/x86/kvm/pmu.c. Essentially it would be doing RDPMC.
Thx for the pointer, appreciated.
> But the overhead will be likely very high, some sampling approach > is likely better.
Indeed. It doesn't actually have to be at every single ftrace begin/exit. But possibly starting with some kind of every nth and then drilling down as the culprit is incrementally singled-out.
-- Karim Yaghmour CEO - Opersys inc. / www.opersys.com http://twitter.com/karimyaghmour
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