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hwpmc_arm64: fill kern.hwpmc.cpuid
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Authored by mhorne on Jun 1 2021, 4:17 PM.

Details

Summary

This will be used to detect supported pmu events. The expected format is
the MIDR register with the revision and variant fields masked. See
lib/libpmc/pmu-events/arch/arm64/mapfile.csv.

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rG FreeBSD src repository
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Event Timeline

mhorne requested review of this revision.Jun 1 2021, 4:17 PM
sys/dev/hwpmc/hwpmc_arm64.c
521–522

Create kern.hwpmc.cpuid.0 etc. (one per CPU) and deprecate kern.hwpmc.cpuid?

sys/dev/hwpmc/hwpmc_arm64.c
521–522

I looked into this a bit, and tried to implement it. It is easy to provide on the kernel side, but the pmu bits in libpmc will need more significant work to plumb the notion of a desired CPU into all paths that invoke the sysctl.

I think it would be best to leave this as a TODO for a more concentrated effort at addressing big.LITTLE in libpmc/hwpmc.

Any further comments? I plan to commit within the next day or two if not.

This revision was not accepted when it landed; it landed in state Needs Review.Jun 30 2021, 7:49 PM
This revision was automatically updated to reflect the committed changes.