[PATCH v3 7/7] perf python: Add counting.py as example for counting perf events

[Ian Rogers <irogers@google.com>]

From: Gautam Menghani <gautam@linux.ibm.com>

Add counting.py - a python version of counting.c to demonstrate
measuring and reading of counts for given perf events.

Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
Ian modified from v2 to make the API take a CPU and thread then
compute from these the appropriate indices. This was discussed as the
preferred API with Arnaldo:
https://lore.kernel.org/linux-perf-users/20250512055748.479786-1-gautam@linux.ibm.com/
The use of a thread_map and cpu_map was also removed to make the code
cleaner, instead the cpus and threads of the parsed evsel are
used. Support for command line events is also added. The indent is
reduced from 8 to 4 to match the preferred python PEP8 indent.
---
 tools/perf/python/counting.py | 36 +++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100755 tools/perf/python/counting.py

diff --git a/tools/perf/python/counting.py b/tools/perf/python/counting.py
new file mode 100755
index 000000000000..02121d2bb11d
--- /dev/null
+++ b/tools/perf/python/counting.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# -*- python -*-
+# -*- coding: utf-8 -*-
+
+import argparse
+import perf
+
+def main(event: str):
+    evlist = perf.parse_events(event)
+
+    for evsel in evlist:
+        evsel.read_format = perf.FORMAT_TOTAL_TIME_ENABLED | perf.FORMAT_TOTAL_TIME_RUNNING
+
+    evlist.open()
+    evlist.enable()
+
+    count = 100000
+    while count > 0:
+        count -= 1
+
+    evlist.disable()
+
+    for evsel in evlist:
+        for cpu in evsel.cpus():
+            for thread in evsel.threads():
+                counts = evsel.read(cpu, thread)
+                print(f"For {evsel} val: {counts.val} enable: {counts.ena} run: {counts.run}")
+
+    evlist.close()
+
+if __name__ == '__main__':
+    ap = argparse.ArgumentParser()
+    ap.add_argument('-e', '--event', help="Events to open", default="cpu-clock,task-clock")
+    args = ap.parse_args()
+    main(args.event)
-- 
2.49.0.1101.gccaa498523-goog