Messages in this thread | | | Date | Fri, 5 Mar 2010 17:46:15 +0100 | From | Robert Richter <> | Subject | Re: [PATCH 0/26] oprofile: Performance counter multiplexing |
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On 26.02.10 15:51:04, Andi Kleen wrote: > That said the biggest problem with oprofile right now that the > new buffer it's using is quite a lot less reliable and drops > events left and right on any non trivial load. That makes > oprofile very unreliable, especially in call graph mode.
(cc'ing Steve)
Andi,
the tests I run with oprofile do not indicate unreliable ring_buffer behavior. Maybe my use cases and loads are different. Can you describe a setup where this may happen for sure? What is the impact, do you have lost samples or inconsistent buffer data? Is the data loss in kernel or user space? Also, I am not aware that the ring_buffer is unreliable for ftrace or tracepoints, where it is heavily used. I really want to find the root cause here.
Thanks,
-Robert
-- Advanced Micro Devices, Inc. Operating System Research Center email: robert.richter@amd.com
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