On 06/26/2013 10:58 AM, Ingo Molnar wrote:
* Nathan Zimmer <nzimmer@xxxxxxx> wrote:
On 06/26/2013 10:12 AM, Dave Hansen wrote:
On 06/26/2013 07:49 AM, Nathan Zimmer wrote:
My guess it is the NMIs overwhelming the system but I have not found a good way
to profile perf gone wild so it is only a guess.
I've got an 80-core system and the symptoms sound similar to perf issues
I'm seeing. Dropping the sample rate helped for me, and there's a patch
in -tip at the moment to do it automatically:
http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=14c63f17b1fde5a575a28e96547a22b451c71fb5
Looks like you've also found that debugging NMIs is fun. :)
More fun then one person can handle.
I'll have to take this patch for a spin.
Please try latest -tip:master, there's a series of patches from Dave that
address this problem category.
Does it only happen with -g, or with regular perf record and/or with perf
top as well?
Thanks,
Ingo
It happens in all those cases, but I notice it most when doing a perf
record -g -a
I'll try the tip series and see how it compares.
Thanks
Nate
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