From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f70.google.com (mail-dl1-f70.google.com [74.125.82.70]) (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 118923AAF54 for ; Sat, 26 Sep 2026 06:21:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790403718; cv=none; b=mUcVOnj9n98OAnGRCvdpmVEfTEXxPrLJv5iJhf/m4O8h3BADcc0lWTUKojwoHhxVMwWGUBrNGakxSfwJ97jLznyAc4nKKUkjal8Dyhjln4pM0EPKAqsSWE+9ESN+IJHYqT8S48Ze0YUQpX9kM9uoO51tPMfg/52Cg7DHrk57hu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790403718; c=relaxed/simple; bh=twa2t5NDF8B2ebIdy+CAqAQm0eyQVti2RL1gCRQSLBU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=jPjt3SJCnJiVbM/d8gVl029RRxsAP9XYlln6UUMt4kZzl6b8uItUBHz7O6unzFIRzbJlto9+uUzVkD+EuVTrgl7kFLTydSzCWBsov73k0Dht+WpCLvHEMDK4s78+Z69Bt8ewUutUNeSO5H8hoRxtSWGmnBXLubEswJ5TLxImRUg= 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=MfOjqACk; arc=none smtp.client-ip=74.125.82.70 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="MfOjqACk" Received: by mail-dl1-f70.google.com with SMTP id a92af1059eb24-147be78cd56so258973c88.1 for ; Fri, 25 Sep 2026 23:21:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790403714; x=1791008514; 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=FBS2LCJ+fW8FuU5Xc7G48myLtCT2mEhsbIcl8X/SXcc=; b=MfOjqACkfSRhxwoY3wVeAPREEHSEKAsXATFDw9jOAlYzK70XK1UhNMou5nlQzvn3/S 4QuiHl7hqldVfD5P64q/jbLfSin04+PfT5uH66vjCUj1JF/Kj+YnCaUi+2yvwzKNnuIC XSXI5j3bib2FWqZ0eSY34QRyHIE+U6/ygpSNkLD8ZTyyh3sxxwSszQmptv2yAgyTQ2OW mOjpkz4TvLMclflZa6ZRbs+t9VsQSddSwnbQjlyi/QMqMpcLIAY1BovwZn6yHsQaj6ai QBYMOB+YgyHFab4FqryiBFF++4ZVjhS217HnhFGs5IDBA1fx5tHYD76Hn6F3cjgklAIs rdVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790403714; x=1791008514; 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=FBS2LCJ+fW8FuU5Xc7G48myLtCT2mEhsbIcl8X/SXcc=; b=T10+lYPvntUcW4YUsSOH2g/yd1KUVRqmLXu/SFywiurxY5J7bacM5s9PDSOP6roolA oAf9LOSxU6Z8yIxWRkGjKD1C7B+ZbU9q/+23+BNq+xSPOy9V7PXlAR+rosBuExowTs/t mnwDPXVND4PoiGQe+f84YyZQ0QuHP1WJ1I2VwOe2As3LPTI7tCORLL+zGaX037Ay2xDx YOPAZkuJDF5XYiulYCnudU/D3BadTjvaY3TGgY+7/fIpvCY4yB/Iuy+YVs5Gl4xHyLNX REq2Eq9BlnyjuXuCgd2HjGmr3RI4YHdK3+J4ej5LdNK43U4Je37xyXO+l4YSHRemzpRV K80g== X-Forwarded-Encrypted: i=1; AKwUvBzJJ2ZS5Dz8GOYuqAPOza4GS+lDJqC3huRclAGMccY+qff9pT/XNNd9U8KCKl+XEgpietjw0cZIIN7IwnE=@vger.kernel.org X-Gm-Message-State: AFuF++nQftL17C8OIpfJXKMgl4ZRHytHrvZVSzqCqECx5pPEsh72lzGp CdCxnsjQ+q8En9jyXTzz0W8PH+2CU3hZGHiiP3idKKjIPY3VYvr67jB+vWGx8UfE9seUagZYbGc y4V6nf+hC2g== X-Received: from dlbrf7.prod.google.com ([2002:a05:7022:f207:b0:144:c0e8:a153]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:1703:b0:143:33de:97ae with SMTP id a92af1059eb24-146ce776c64mr2265860c88.20.1790403713842; Fri, 25 Sep 2026 23:21:53 -0700 (PDT) Date: Fri, 25 Sep 2026 23:19:55 -0700 In-Reply-To: <20260926062029.800743-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260923181213.3032038-1-irogers@google.com> <20260926062029.800743-1-irogers@google.com> X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog Message-ID: <20260926062029.800743-29-irogers@google.com> Subject: [PATCH v4 28/49] perf python: Port rw-by-pid from Perl to perf module From: Ian Rogers To: irogers@google.com, acme@kernel.org, alice.mei.rogers@gmail.com, james.clark@linaro.org, leo.yan@linux.dev, namhyung@kernel.org Cc: adrian.hunter@intel.com, dapeng1.mi@linux.intel.com, linux-kernel@vger.kernel.org, linux-perf-users@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 rw-by-pid.pl with a standalone Python script in tools/perf/python/rw-by-pid.py using the perf Python module. Improvements compared to the legacy Perl script: - Remove the dependency on libperl and Perf::Trace::Util. - Convert unsigned 32-bit and 64-bit error return values (0xfffff000..0xffffffff and >= 0x8000000000000000) to negative errnos so failed read/write syscalls are recorded in the error table rather than inflating bytes_read / bytes_written. - Add argparse CLI support (-i/--input) and full type annotations. Add a shell test (test_rw_by_pid_python.sh) to verify the standalone script. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- tools/perf/python/rw-by-pid.py | 205 ++++++++++++++++++ .../perf/tests/shell/test_rw_by_pid_python.sh | 75 +++++++ 2 files changed, 280 insertions(+) create mode 100755 tools/perf/python/rw-by-pid.py create mode 100755 tools/perf/tests/shell/test_rw_by_pid_python.sh diff --git a/tools/perf/python/rw-by-pid.py b/tools/perf/python/rw-by-pid.py new file mode 100755 index 000000000000..8e2d1dbd9a08 --- /dev/null +++ b/tools/perf/python/rw-by-pid.py @@ -0,0 +1,205 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Display r/w activity for all processes.""" +from __future__ import annotations + +import argparse +from collections import defaultdict +import sys +from typing import Optional, Dict, List, Tuple, Any +import perf + +class RwByPid: + """Tracks and displays read/write activity by PID.""" + def __init__(self) -> None: + self.reads: Dict[int, Dict[str, Any]] = defaultdict( + lambda: { + "bytes_requested": 0, + "bytes_read": 0, + "total_reads": 0, + "comm": "", + "errors": defaultdict(int), + } + ) + self.writes: Dict[int, Dict[str, Any]] = defaultdict( + lambda: { + "bytes_requested": 0, + "bytes_written": 0, + "total_writes": 0, + "comm": "", + "errors": defaultdict(int), + } + ) + self.unhandled: Dict[str, int] = defaultdict(int) + self.session: Optional[perf.session] = None + + def _handle_sys_enter_read(self, pid: int, comm: str, sample: perf.sample_event) -> None: + try: + count = sample.count + self.reads[pid]["bytes_requested"] += count + self.reads[pid]["total_reads"] += 1 + self.reads[pid]["comm"] = comm + except AttributeError: + self.unhandled["sys_enter_read_attr_err"] += 1 + + def _handle_sys_exit_read(self, pid: int, sample: perf.sample_event, comm: str = "") -> None: + try: + ret = sample.ret + # Convert unsigned 64-bit or 32-bit tracepoint return values to signed integers. + # Because kernel read/write transfers are bounded by MAX_RW_COUNT (0x7ffff000 < 2 GiB), + # 0xfffff000..0xffffffff is always a 32-bit negative errno even on 64-bit hosts. + if ret >= 0x8000000000000000: + ret -= 0x10000000000000000 + elif 0xfffff000 <= ret <= 0xffffffff: + ret -= 0x100000000 + if not self.reads[pid]["comm"] and comm: + self.reads[pid]["comm"] = comm + if ret >= 0: + self.reads[pid]["bytes_read"] += ret + else: + self.reads[pid]["errors"][ret] += 1 + except AttributeError: + self.unhandled["sys_exit_read_attr_err"] += 1 + + def _handle_sys_enter_write(self, pid: int, comm: str, sample: perf.sample_event) -> None: + try: + count = sample.count + self.writes[pid]["bytes_requested"] += count + self.writes[pid]["total_writes"] += 1 + self.writes[pid]["comm"] = comm + except AttributeError: + self.unhandled["sys_enter_write_attr_err"] += 1 + + def _handle_sys_exit_write(self, pid: int, sample: perf.sample_event, comm: str = "") -> None: + try: + ret = sample.ret + # Convert unsigned 64-bit or 32-bit tracepoint return values to signed integers. + # Because kernel read/write transfers are bounded by MAX_RW_COUNT (0x7ffff000 < 2 GiB), + # 0xfffff000..0xffffffff is always a 32-bit negative errno even on 64-bit hosts. + if ret >= 0x8000000000000000: + ret -= 0x10000000000000000 + elif 0xfffff000 <= ret <= 0xffffffff: + ret -= 0x100000000 + if not self.writes[pid]["comm"] and comm: + self.writes[pid]["comm"] = comm + if ret >= 0: + self.writes[pid]["bytes_written"] += ret + else: + self.writes[pid]["errors"][ret] += 1 + except AttributeError: + self.unhandled["sys_exit_write_attr_err"] += 1 + + def process_event(self, sample: perf.sample_event) -> None: + """Process events.""" + event_name = str(sample.evsel) + if event_name.startswith("evsel(") and event_name.endswith(")"): + event_name = event_name[6:-1] + event_name = "".join(c if c.isprintable() else "?" for c in event_name) + pid = sample.sample_pid + + assert self.session is not None + try: + thread = self.session.find_thread(pid, sample.sample_tid) + comm = (thread.comm() if thread else None) or "unknown" + except (TypeError, AttributeError): + comm = "unknown" + comm = "".join(c if c.isprintable() else "?" for c in comm) + + if event_name == "syscalls:sys_enter_read": + self._handle_sys_enter_read(pid, comm, sample) + elif event_name == "syscalls:sys_exit_read": + self._handle_sys_exit_read(pid, sample, comm) + elif event_name == "syscalls:sys_enter_write": + self._handle_sys_enter_write(pid, comm, sample) + elif event_name == "syscalls:sys_exit_write": + self._handle_sys_exit_write(pid, sample, comm) + else: + self.unhandled[event_name] += 1 + + def print_totals(self) -> None: + """Print summary tables.""" + print("read counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# reads':>10s} " + f"{'bytes_requested':>15s} {'bytes_read':>10s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*15} {'-'*10}") + + for pid, data in sorted(self.reads.items(), + key=lambda kv: kv[1]["bytes_read"], reverse=True): + print( + f"{pid:6d} {data['comm']:<20s} {data['total_reads']:10d} " + f"{data['bytes_requested']:15d} {data['bytes_read']:10d}" + ) + + print("\nfailed reads by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'error #':>7s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*7} {'-'*10}") + + errcounts: List[Tuple[int, str, int, int]] = [] + for pid, data in self.reads.items(): + for error, count in data["errors"].items(): + errcounts.append((pid, data["comm"], error, count)) + + for pid, comm, error, count in sorted(errcounts, key=lambda x: x[3], reverse=True): + print(f"{pid:6d} {comm:<20s} {error:7d} {count:10d}") + + print("\nwrite counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# writes':>10s} " + f"{'bytes_requested':>15s} {'bytes_written':>15s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*15} {'-'*15}") + + for pid, data in sorted(self.writes.items(), + key=lambda kv: kv[1]["bytes_written"], reverse=True): + print( + f"{pid:6d} {data['comm']:<20s} {data['total_writes']:10d} " + f"{data['bytes_requested']:15d} {data['bytes_written']:15d}" + ) + + print("\nfailed writes by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'error #':>7s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*7} {'-'*10}") + + errcounts = [] + for pid, data in self.writes.items(): + for error, count in data["errors"].items(): + errcounts.append((pid, data["comm"], error, count)) + + for pid, comm, error, count in sorted(errcounts, key=lambda x: x[3], reverse=True): + print(f"{pid:6d} {comm:<20s} {error:7d} {count:10d}") + + 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: + # Break the reference cycle between perf.session and self.process_event + # because perf.session lacks cyclic GC support (tp_traverse). + self.session = None + self.print_totals() + +def main() -> None: + """Main function.""" + parser = argparse.ArgumentParser(description="Trace r/w activity by PID") + parser.add_argument("-i", "--input", default="perf.data", help="Input file") + args = parser.parse_args() + + analyzer = RwByPid() + 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_rw_by_pid_python.sh b/tools/perf/tests/shell/test_rw_by_pid_python.sh new file mode 100755 index 000000000000..da8b065d43de --- /dev/null +++ b/tools/perf/tests/shell/test_rw_by_pid_python.sh @@ -0,0 +1,75 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# rw-by-pid python test + +set -e + +shelldir=$(dirname "$0") +# shellcheck source=lib/setup_python.sh +. "${shelldir}"/lib/setup_python.sh + +if ! "$PYTHON" -c 'import perf' > /dev/null 2>&1; then + echo "Skipping test, perf python module not found" + exit 2 +fi + +script_dir="$(dirname "$0")/../../python" +script_path="${script_dir}/rw-by-pid.py" + +if ! perf check feature -q libtraceevent > /dev/null 2>&1; then + echo "Skipping test, libtraceevent is disabled" + exit 2 +fi + +if [ ! -f "$script_path" ]; then + echo "Skipping test, rw-by-pid.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=$(mktemp /tmp/perf.out.XXXXXX) + +echo "Testing rw-by-pid.py..." + +# Create a perf.data file. Try to get tracepoint data. +if perf list | grep -q "syscalls:sys_enter_read"; then + ev="syscalls:sys_enter_read,syscalls:sys_exit_read" + ev="${ev},syscalls:sys_enter_write,syscalls:sys_exit_write" + perf record -e "$ev" -a -o "${temp_data}" \ + -- dd if=/dev/urandom of=/dev/null bs=1M count=10 >/dev/null 2>&1 || \ + { echo "Skipping test, perf record failed"; exit 2; } +else + echo "Skipping test, no syscalls:sys_enter_read 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}" > "${temp_out}"; then + echo "rw-by-pid.py test failed" + err=1 +else + if ! grep -E -q "^ *[0-9]+" "${temp_out}"; then + echo "Failed to find metric data rows in output" + cat "${temp_out}" + err=1 + else + echo "rw-by-pid test passed." + fi +fi +rm -f "${temp_out}" + +exit $err -- 2.56.0.rc1.315.gc6ed9934b7-goog