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Perf hardware events odroid XU3 #181

Open emilienkofman opened 8 years ago

emilienkofman commented 8 years ago

Hello,

I've been compiling and installing a new kernel from source (branch odroidxu3-3.10.y) in order to access the perf hardware events. Hopefully I could find a patch for it here https://github.com/kensoc/kendroid_kernel_hardkernel_odroidxu3/commit/e90ac2cb272437fe40e947cbcab148b65591b06d.

It looks like this actually works, do you know why this has not been merged? Sincerely.

edit: This only works for A15 hardware counters, but I guess it's better than none at all. I you know how to read both A7 and A15 counters without compiling again, please let me know.

mdrjr commented 8 years ago

Hello @emilienkofman

The reason behind we didn't leave performance counters enabled is because at this time you can only enable it for A15 or A7 and not both clusters at the same time.

As described on the official wiki: http://odroid.com/dokuwiki/doku.php?id=en:odroid_linux_performance_counter

emilienkofman commented 8 years ago

Thank you, I thought that maybe we could enable one or the other as it's still a better solution that none of them? As long as it's documented somewhere! I admit I have no clue about enabling both, can you suggest something? Maybe it has been fixed in an other project that uses the same Exynos HMP chip?