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Differential D60563

hwpmc: fix multipart sample accounting
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Authored by afscoelho_gmail.com on Sat, Oct 10, 1:22 AM.
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F175632888: D60563.id189318.diff
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Details

Reviewers
mhorne
gnn
ali_mashtizadeh.com
Group Reviewers
pmc
Summary

Fix how multipart samples (IBS) are stored:

  • Clear and count the whole 8-byte header (two slots on 32-bit).
  • Count the payload when the callchain depth is 1.
  • Do not reserve an extra slot for the user callchain.
  • Use the real PC, not the header, for profil(2).
  • Make sure a sample slot can hold the largest payload.

Add <sys/pmclog.h> helpers to find the callchain in a multipart record.

Test Plan

Built amd64 GENERIC + hwpmc.ko, GENERIC without HWPMC_HOOKS, and arm64.
Ran tests/sys/pmc on AMD Zen 6 (LBR v2).

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Skipped
Unit
Tests Skipped
Build Status
Buildable 77936
Build 74819: arc lint + arc unit

Revision Contents
Changeset List

PathSize
share/
man/
man4/
7 lines
sys/
dev/
hwpmc/
2 lines
52 lines
sys/
63 lines

Diff 189318

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share/man/man4/hwpmc.4

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sys/dev/hwpmc/hwpmc_logging.c

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sys/dev/hwpmc/hwpmc_mod.c

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sys/sys/pmclog.h

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