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macosperformancecpu-cachekernel-extension

How to measure L1, L2, L3 cache hits & misses in OSX

I've a C++ program and I would like to quantify it's performance by checking the number of hits and misses against the CPU cache.

What's the best way to do it?

I tried using Intel's Performance Counter Monitor but it uses an unsigned Kernel Extension which are disabled on Yosemite. I can obviously disable the check to not load unsigned kexts but I wouldn't like to go down that path.

Is there any other possible way that I'm unaware of?

Solution

  • You can enable unsigned kernel extensions with OS X (reboot afterwards required):

    sudo nvram boot-args=kext-dev-mode=1

    This enables developer mode on your machine and you can run Intel Performance Counter Monitor as long at it supports Mac OS X 10.10 (Yosemite) in general.

    Don't forget to disable it again after you are done with testing (security-issue otherwise):

    sudo nvram boot-args=kext-dev-mode=0

    As far as I know Intel's tool is far better than cache grind because it uses actual counters from the hardware instead of simulating an cpu and it's cache characteristics in software.