linux-kernel - [PATCH v2 0/3] Fix incorrect counts when count the same uncore event multiple times

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Message-ID: <20250327225651.642965-1-ctshao@google.com>
Date: Thu, 27 Mar 2025 15:48:15 -0700
From: Chun-Tse Shao <ctshao@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Chun-Tse Shao <ctshao@...gle.com>, peterz@...radead.org, mingo@...hat.com, 
	acme@...nel.org, namhyung@...nel.org, mark.rutland@....com, 
	alexander.shishkin@...ux.intel.com, jolsa@...nel.org, irogers@...gle.com, 
	adrian.hunter@...el.com, kan.liang@...ux.intel.com, james.clark@...aro.org, 
	howardchu95@...il.com, yeoreum.yun@....com, linux@...blig.org, 
	ak@...ux.intel.com, weilin.wang@...el.com, asmadeus@...ewreck.org, 
	linux-perf-users@...r.kernel.org
Subject: [PATCH v2 0/3] Fix incorrect counts when count the same uncore event
 multiple times

Let's take a look an example, the machine is SKX with 6 IMC devices.

  perf stat -e clockticks,clockticks -I 1000
  #           time             counts unit events
       1.001127430      6,901,503,174      uncore_imc_0/clockticks/
       1.001127430      3,940,896,301      uncore_imc_0/clockticks/
       2.002649722        988,376,876      uncore_imc_0/clockticks/
       2.002649722        988,376,141      uncore_imc_0/clockticks/
       3.004071319      1,000,292,675      uncore_imc_0/clockticks/
       3.004071319      1,000,294,160      uncore_imc_0/clockticks/

1) The events name should not be uniquified.
2) The initial count for the first `clockticks` is doubled.
3) Subsequent count only report for the first IMC device.

The first patch fixes 1) and 3), and the second patch fixes 2).

After these fix:

  perf stat -e clockticks,clockticks -I 1000
  #           time             counts unit events
       1.001127586      4,126,938,857      clockticks
       1.001127586      4,121,564,277      clockticks
       2.001686014      3,953,806,350      clockticks
       2.001686014      3,953,809,541      clockticks
       3.003121403      4,137,750,252      clockticks
       3.003121403      4,137,749,048      clockticks

I also tested `-A`, `--per-socket`, `--per-die` and `--per-core`, all
looks good.

Ian tested `hybrid-merge` and `hwmon`, all looks good as well.

Chun-Tse Shao (1):
  perf test: Add stat uniquifying test

Ian Rogers (2):
  perf evlist: Make uniquifying counter names consistent
  perf parse-events: Use wildcard processing to set an event to merge
    into

 tools/perf/builtin-record.c                   |   7 +-
 tools/perf/builtin-top.c                      |   7 +-
 .../tests/shell/stat+event_uniquifying.sh     |  69 ++++++++
 tools/perf/util/evlist.c                      |  66 +++++---
 tools/perf/util/evlist.h                      |   3 +-
 tools/perf/util/evsel.c                       | 119 ++++++++++++-
 tools/perf/util/evsel.h                       |  11 +-
 tools/perf/util/parse-events.c                |  86 +++++++---
 tools/perf/util/stat-display.c                | 160 ++----------------
 tools/perf/util/stat.c                        |  40 +----
 10 files changed, 329 insertions(+), 239 deletions(-)
 create mode 100755 tools/perf/tests/shell/stat+event_uniquifying.sh

--
v2:
  - Fixes for `hwmon` and `--hybrid-merge`.
  - Add a test for event uniquifying.

v1: lore.kernel.org/20250326234758.480431-1-ctshao@...gle.com
2.49.0.472.ge94155a9ec-goog