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

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Reviewers

andrew
emaste
manu
br
gnn

Commits

rGd876c5a052fb: hwpmc_arm64: fill kern.hwpmc.cpuid
rG5867cccdc49d: hwpmc_arm64: fill kern.hwpmc.cpuid

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.

Diff Detail

Repository

rG FreeBSD src repository

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Automatic diff as part of commit; lint not applicable.

Unit

Automatic diff as part of commit; unit tests not applicable.

Event Timeline

mhorne created this revision.Jun 1 2021, 4:17 PM

Herald added a subscriber: imp. · View Herald TranscriptJun 1 2021, 4:17 PM

mhorne requested review of this revision.Jun 1 2021, 4:17 PM

Harbormaster completed remote builds in B39648: Diff 90276.Jun 1 2021, 4:17 PM

mhorne added a reviewer: br.Jun 1 2021, 4:36 PM

andrew added inline comments.Jun 2 2021, 10:15 AM

sys/dev/hwpmc/hwpmc_arm64.c
521–522	Create `kern.hwpmc.cpuid.0` etc. (one per CPU) and deprecate `kern.hwpmc.cpuid`?

mhorne added inline comments.Jun 22 2021, 3:13 PM

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.