libpmc: userland support and pmc.rapl.3 for the RAPL class
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Authored by afscoelho_gmail.com on Fri, Jul 3, 6:00 PM.

Details

Reviewers

ali_mashtizadeh.com
gnn
mhorne
alfredo
janeri_gmail.com
raghavendra.kt_amd.com

Group Reviewers

pmc

Summary

Register PMC_CLASS_RAPL in libpmc: event table, allocator, class-table
descriptor, and the event-name/class-listing lookups, all x86-guarded
and modeled on the TSC class. Energy events are read-only and
unqualified. The class prefix (RAPL-) supplies the friendly spelling, so
pmcstat -S rapl-energy-pkg resolves to the canonical ENERGY_PKG event.

Add a pmc.rapl.3 manual page documenting the events, counter scope, the
microjoule unit and wrap handling, and the NUMA/package domain mapping;
link it from pmc.3.

Diff Detail

Repository

rG FreeBSD src repository

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Unit

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Build Status

Buildable 74804
Build 71687: arc lint + arc unit

Event Timeline

afscoelho_gmail.com created this revision.Fri, Jul 3, 6:00 PM

Herald added subscribers: ziaee, imp. · View Herald TranscriptFri, Jul 3, 6:00 PM

afscoelho_gmail.com requested review of this revision.Fri, Jul 3, 6:00 PM

afscoelho_gmail.com added a parent revision: D58028: hwpmc: add RAPL energy-counter class (AMD + Intel).

Harbormaster completed remote builds in B74511: Diff 181268.Fri, Jul 3, 6:01 PM

afscoelho_gmail.com added reviewers: gnn, mhorne, alfredo, janeri_gmail.com, raghavendra.kt_amd.com, pmc.Fri, Jul 3, 6:18 PM

afscoelho_gmail.com mentioned this in D55603: amdrapl: Introduce amdrapl driver.Fri, Jul 3, 6:30 PM

ali_mashtizadeh.com added inline comments.Sun, Jul 5, 11:41 PM

lib/libpmc/pmc.rapl.3
28	sentence after the semicolon doesn't follow. If your talking about the bug fix drop it?
41	Maybe something close to: The RAPL PMC driver provides a virtual 64-bit counter that is guaranteed to be monotonic, by periodically sampling the 32-bit hardware counters that wrap frequently. Saying the kernel folds them is awkward.

mhorne accepted this revision.Fri, Jul 10, 4:48 PM

mhorne added inline comments.

lib/libpmc/libpmc.c
895	Are the casts needed?
899

This revision is now accepted and ready to land.Fri, Jul 10, 4:48 PM

Address review feedback: drop the unneeded (int) casts on pe in rapl_allocate_pmc, since the RAPL bounds are enum pmc_event members (mhorne); reword the microjoule-scaling sentence and describe wrap handling as a virtual 64-bit counter in pmc.rapl.3 (ali_mashtizadeh).

This revision now requires review to proceed.Tue, Jul 14, 7:51 PM

Harbormaster completed remote builds in B74804: Diff 181991.Tue, Jul 14, 7:51 PM

Address review: use explicit 'ctrspec != NULL' in rapl_allocate_pmc (mhorne, style(9)).

Harbormaster completed remote builds in B74813: Diff 182006.Tue, Jul 14, 10:24 PM

afscoelho_gmail.com marked 2 inline comments as done.Tue, Jul 14, 10:30 PM

afscoelho_gmail.com added inline comments.

lib/libpmc/libpmc.c
895	No, they are not! I copied this from soft_allocate_pmc and didn't check, thanks for the warning !
lib/libpmc/pmc.rapl.3
28	right, I reworded it.
41	I did as you suggested, thanks!