Differential D26113

libpmc: add support for POWER8/9 PMCs
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Authored by luporl on Aug 18 2020, 7:08 PM.

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jhibbits

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PowerPC

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rS367391: libpmc: add support for POWER8/9 PMCs

Summary

This change adds support for POWER8/9 performance counters.

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Buildable 33056
Build 30439: arc lint + arc unit

Event Timeline

luporl requested review of this revision.Aug 18 2020, 7:08 PM

luporl created this revision.

Harbormaster completed remote builds in B33056: Diff 75966.Aug 18 2020, 7:08 PM

luporl added a parent revision: D26110: [PowerPC64] hwpmc: add support for POWER8/9 PMCs.Aug 18 2020, 7:09 PM

One thing we do have is the full power8/9 pmcs in src/lib/libpmc/pmu-events/arch. I think these just need to be hooked up

In D26113#579628, @kbowling wrote:

One thing we do have is the full power8/9 pmcs in src/lib/libpmc/pmu-events/arch. I think these just need to be hooked up

Right, yes, this helps a lot.
But taking a look on how these get hooked up on i386/amd64, it seems there is a reasonable amount of work to do:

libpmc_pmu_util.c needs to be ported to PPC64.
In hwpmc module, PPC64 allocate/release pmc methods need to be adapted to support PMC allocation with settings coming from libpmc. Also, register programming is a bit different for these events, compared to the basic ones of ISA 2.07.
Probably something else I'm missing.

So, it doesn't seem a whole lot of work, but I think it's enough to justify doing it a separate patch later.

luporl mentioned this in D26114: pmcstat: fix PPC kernel symbol resolution.Aug 21 2020, 2:43 PM

luporl mentioned this in D26110: [PowerPC64] hwpmc: add support for POWER8/9 PMCs.Sep 23 2020, 5:59 PM

Rename ppcpnv/powernv to power8.

The PowerNV naming could cause confusion, as these changes work with pseries/QEMU too.
POWER8 describes more correctly the support target being added, and POWER9 is fully backwards compatible with it.

Harbormaster completed remote builds in B33777: Diff 77448.Sep 23 2020, 6:19 PM

jhibbits accepted this revision.Nov 3 2020, 10:27 PM

This revision is now accepted and ready to land.Nov 3 2020, 10:27 PM

Closed by commit rS367391: libpmc: add support for POWER8/9 PMCs (authored by luporl). · Explain WhyNov 5 2020, 8:10 PM

This revision was automatically updated to reflect the committed changes.

luporl added a commit: rS367391: libpmc: add support for POWER8/9 PMCs.

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