From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE7A3367294 for ; Mon, 21 Sep 2026 05:08:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789967303; cv=none; b=fidItzLaxdF95fYaBL6eSqvPQj8EI/1KA1K4dtqwiYbesyL8kBhqSHBcu2sktCjz8KRs+V805pudqde02K0l8e12iWRcQWi8CwrZVDm/D8MYdE87ZfsJtK3NERR/zwEeS6+sPYkHYZrGGo9BoxgUU4rYfoUqC8VUTuoel27+Bdo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789967303; c=relaxed/simple; bh=vvC/9bKdNtW1D6SIoM9azCb1dqac6AgXW2gBVJIKNwk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=T5nJFMHLt8MwU6EvD2hXuXIhby7hMqtoKPl01LmQLC62P1mDZ6CChp0hMByr5fW0HG9zyoV3tiG7JVRuQSmSqjYbP5IBP0mjJsiXq4n3dG23sXLkvp/WwVZh9YMkSqquTGIJalB9V6Zi9iqccwj8Hz5xOLdDLaeAW3uG+FjH/5A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=tpsYh+2D; arc=none smtp.client-ip=209.85.216.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tpsYh+2D" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-38ecc48b3c2so6789097a91.1 for ; Sun, 20 Sep 2026 22:08:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789967301; x=1790572101; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=1PQAolzi58qHU7RRZNY19ENhVjam2IcWgpCojxZBrHc=; b=tpsYh+2DH5YSNnfzYExYyKdR+FzrchQZf0Szbs4v5jiFpHOxWbPCnFMsxMum123bv/ rXXobIwyeMbWfzoxj++d44OqmhVoHKy+xMYXJeOhJPGHauHvIVauSULCz+/ji/6CA0QJ QQPusnaUt9823vp09AfhIsoiPqssqpu5j43p7FQQhNIY/aI4e9KXDzdDHk4dnV/2xP+/ 6MbwQneZXAGYzV7Z/2VOgY0AKWMbVWM5aaNcpDecSntheghVsEZEtH20ek/PLKIm+Yeu eso49/wZ/ceT9j2Mu6Ptm8NEXercSztzvadMC2rea0awcbWMzoWF33ikokJ667Itz/ey Z9gA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789967301; x=1790572101; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=1PQAolzi58qHU7RRZNY19ENhVjam2IcWgpCojxZBrHc=; b=T2STp/Q5pCvuykcJwa2nKEk2nuuitBJXqO7T7Z59YcEBqkARhRkDXChyhWRKBuEQRL ELNRtn4sdAfnNznDL9VltqNYSyVLuuI7LnQy6jjzEdBHDzs/ChkCZF7kWxiXkenzL/rQ oFciSlYYduRngj3yX89UslqwnooYLDeMFbzKGk4F8MJ1r9k+q0bEGcqzu7glAx015V67 4ssXRPGfylZWbSvjyIyvxEYKzZXFZrFnD6qpKv+CCjYimpxQSD7agBbXG2GNunjFr5Iv KKxGtvFz2irB9blt8je/L+uL5VJCtmBKR6T3Gh1Dbl0FBzA9u5J1KoPdiZJVhMghD+WH Ef8Q== X-Forwarded-Encrypted: i=1; AKwUvBxuVdQNtKI2EzzKcBNavJAd5GDZSxu/k5Sg+f5KlAK2/T6/TvPiUakKUlUXN5k2K9+C5dIDWQn0yr6CKNIUguOm@vger.kernel.org X-Gm-Message-State: AFuF++nUWwrhuzgL9Axm7kd/4AdCeahYtLm5d/9Uf6oMdjRi/CNtem3d c/tfWV3uHUgLEsldTMql4U5/rUnDKp+/ITgq6uv2GUogZWFTAw3o/1KDFeTC5TIWTOugRYUfP2K VpkTs0zc81g== X-Received: from dlxx3.prod.google.com ([2002:a05:7022:4083:b0:143:9303:fb4c]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:384d:b0:39e:6c6a:656d with SMTP id 98e67ed59e1d1-39e6c6a6757mr8467803a91.48.1789967301154; Sun, 20 Sep 2026 22:08:21 -0700 (PDT) Date: Sun, 20 Sep 2026 22:06:51 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Message-ID: <59486d9f5b83ad06a154ed3cb164d36106009df7.1789966896.git.irogers@google.com> Subject: [PATCH v2 33/49] perf python: Port wakeup-latency from Perl to perf module From: Ian Rogers To: irogers@google.com, acme@kernel.org, alice.mei.rogers@gmail.com, linux-perf-users@vger.kernel.org, namhyung@kernel.org Cc: adrian.hunter@intel.com, dapeng1.mi@linux.intel.com, james.clark@linaro.org, leo.yan@linux.dev, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, tmricht@linux.ibm.com Content-Type: text/plain; charset="UTF-8" Replace the legacy Perl script wakeup-latency.pl with a standalone Python script in tools/perf/python/wakeup-latency.py using the perf Python module. Improvements compared to the legacy Perl script: - Remove the dependency on libperl and Perf::Trace::Util. - Guard print_totals() when total_wakeups == 0 (printing 'N/A' instead of dividing by zero when a trace contains no matched wakeup/switch pairs). - Add argparse CLI options (-i/--input) and full type annotations. Add a shell test (test_wakeup_latency_python.sh) to verify the standalone script. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- tools/perf/python/wakeup-latency.py | 97 +++++++++++++++++++ .../tests/shell/test_wakeup_latency_python.sh | 83 ++++++++++++++++ 2 files changed, 180 insertions(+) create mode 100755 tools/perf/python/wakeup-latency.py create mode 100755 tools/perf/tests/shell/test_wakeup_latency_python.sh diff --git a/tools/perf/python/wakeup-latency.py b/tools/perf/python/wakeup-latency.py new file mode 100755 index 000000000000..c7fb48225d47 --- /dev/null +++ b/tools/perf/python/wakeup-latency.py @@ -0,0 +1,97 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Display avg/min/max wakeup latency.""" +from __future__ import annotations + +import argparse +from collections import defaultdict +import sys +from typing import Optional, Dict +import perf + +class WakeupLatency: + """Tracks and displays wakeup latency statistics.""" + def __init__(self) -> None: + self.last_wakeup: Dict[int, int] = defaultdict(int) + self.max_wakeup_latency: int = 0 + self.min_wakeup_latency: Optional[int] = None + self.total_wakeup_latency = 0 + self.total_wakeups = 0 + self.unhandled: Dict[str, int] = defaultdict(int) + self.session: Optional[perf.session] = None + + def process_event(self, sample: perf.sample_event) -> None: + """Process events.""" + event_name = str(sample.evsel) + sample_time = sample.sample_time + + if "sched:sched_wakeup" in event_name: + try: + pid = sample.pid + self.last_wakeup[pid] = sample_time + except AttributeError: + self.unhandled[event_name] += 1 + elif "sched:sched_switch" in event_name: + try: + next_pid = sample.next_pid + wakeup_ts = self.last_wakeup.get(next_pid, 0) + if wakeup_ts: + latency = sample_time - wakeup_ts + self.max_wakeup_latency = max(self.max_wakeup_latency, latency) + if self.min_wakeup_latency is None: + self.min_wakeup_latency = latency + else: + self.min_wakeup_latency = min(self.min_wakeup_latency, latency) + self.total_wakeup_latency += latency + self.total_wakeups += 1 + del self.last_wakeup[next_pid] + except AttributeError: + self.unhandled[event_name] += 1 + else: + self.unhandled[event_name] += 1 + + def print_totals(self) -> None: + """Print summary statistics.""" + print("wakeup_latency stats:\n") + print(f"total_wakeups: {self.total_wakeups}") + if self.total_wakeups: + avg = self.total_wakeup_latency // self.total_wakeups + print(f"avg_wakeup_latency (ns): {avg}") + print(f"min_wakeup_latency (ns): {self.min_wakeup_latency}") + print(f"max_wakeup_latency (ns): {self.max_wakeup_latency}") + else: + print("avg_wakeup_latency (ns): N/A") + print("min_wakeup_latency (ns): N/A") + print("max_wakeup_latency (ns): N/A") + + if self.unhandled: + print("\nunhandled events:\n") + print(f"{'event':<40s} {'count':>10s}") + print(f"{'-'*40} {'-'*10}") + for event_name, count in self.unhandled.items(): + print(f"{event_name:<40s} {count:10d}") + + def run(self, input_file: str) -> None: + """Run the session.""" + self.session = perf.session(perf.data(input_file), sample=self.process_event) + try: + self.session.process_events() + finally: + self.session = None + self.print_totals() + +def main() -> None: + """Main function.""" + parser = argparse.ArgumentParser(description="Trace wakeup latency") + parser.add_argument("-i", "--input", default="perf.data", help="Input file") + args = parser.parse_args() + + analyzer = WakeupLatency() + try: + analyzer.run(args.input) + except IOError as e: + print(e, file=sys.stderr) + sys.exit(1) + +if __name__ == "__main__": + main() diff --git a/tools/perf/tests/shell/test_wakeup_latency_python.sh b/tools/perf/tests/shell/test_wakeup_latency_python.sh new file mode 100755 index 000000000000..d68c9b31d6ed --- /dev/null +++ b/tools/perf/tests/shell/test_wakeup_latency_python.sh @@ -0,0 +1,83 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# wakeup-latency python test + +set -e + +shelldir=$(dirname "$0") +# shellcheck source=lib/setup_python.sh +. "${shelldir}"/lib/setup_python.sh + +if ! "$PYTHON" -c 'import perf' > /dev/null 2>&1; then + echo "Skipping test, perf python module not found" + exit 2 +fi + +if ! perf check feature -q libtraceevent; then + echo "Skipping test, libtraceevent is disabled" + exit 2 +fi + +script_dir="$(dirname "$0")/../../python" +script_path="${script_dir}/wakeup-latency.py" + +if [ ! -f "$script_path" ]; then + echo "Skipping test, wakeup-latency.py not found at $script_path" + exit 2 +fi + +err=0 +temp_data="" +temp_out="" + +cleanup() { + rm -f "${temp_data}" "${temp_out}" +} +trap 'cleanup' EXIT TERM INT + +temp_data=$(mktemp /tmp/perf.data.XXXXXX) +temp_out=$(mktemp /tmp/perf.out.XXXXXX) + +echo "Testing wakeup-latency.py..." + +# Create a perf.data file. Try to get tracepoint data. +if perf list | grep -q "sched:sched_wakeup"; then + ev="sched:sched_wakeup,sched:sched_wakeup_new,sched:sched_switch" + perf record -e "$ev" -a -o "${temp_data}" \ + -- sleep 0.1 >/dev/null 2>&1 || \ + { echo "Skipping test, perf record failed"; exit 2; } +else + echo "Skipping test, no sched:sched_wakeup event" + exit 2 +fi + + +if [ ! -s "${temp_data}" ]; then + echo "Skipping test, perf record failed to create data" + exit 2 +fi + +# Check that the script executes +if ! "$PYTHON" "$script_path" -i "${temp_data}" > "${temp_out}"; then + echo "wakeup-latency.py test failed" + err=1 +else + if ! grep -E -q "avg_wakeup_latency.*[0-9]+" "${temp_out}"; then + echo "Failed to find metric data rows" + err=1 + else + echo "wakeup-latency test passed." + fi +fi + +# Also test zero-wakeups / unhandled events path to verify division-by-zero protection +if perf record -e cycles -o "${temp_data}" -- perf test -w noploop >/dev/null 2>&1; then + if ! "$PYTHON" "$script_path" -i "${temp_data}" > "${temp_out}" || \ + ! grep -q "avg_wakeup_latency (ns): N/A" "${temp_out}"; then + echo "wakeup-latency zero-wakeups guard test failed" + err=1 + fi +fi +rm -f "${temp_out}" + +exit $err -- 2.55.0.1082.g2b9226bbc0-goog