From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f198.google.com (mail-dy1-f198.google.com [74.125.82.198]) (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 6435B41DEDF for ; Wed, 23 Sep 2026 18:14:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790187273; cv=none; b=gllu4myyvsy/BGG3elf44KiaxKkSm4ocNrXEjrqLzxHT/eNLEXJb9hKDwSoBRh31rJwhPCQtbYXuDwGT9ky3Lid9jstoOPMHI7oKXGpQnezrW7EE2uWmWsJ6gm5M3/sNkSrhfY4Rbf9CA6bn+yGrCC3wRSmQdUng0cOk9hoQhOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790187273; c=relaxed/simple; bh=fTDYVdhZt+IkFc/ApmZtGydMwuCOtccqN1GaMfDfLWE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=PwsGF3gNYzyXiS4/fMhJjLmgor+OdClKIZBVCIgIV7dN3/LIF2XZFUlCrwUr3udr15p3GG2TiMLSu6UZmoHR3xxuDj6cWpVudW8V49uboVWSy/sR87+9pkyes9g07xAx3NevJCQ5aZ5UeyHTnZ9qUW+8B6LhV47IuwlGZr+Zwo8= 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=BGqFA2CM; arc=none smtp.client-ip=74.125.82.198 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="BGqFA2CM" Received: by mail-dy1-f198.google.com with SMTP id 5a478bee46e88-32ab0911226so194569eec.0 for ; Wed, 23 Sep 2026 11:14:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790187262; x=1790792062; 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=9vdBhccq/94gqQzrXMG/7AB+kInwb5J5Iuo7pDxt+Tw=; b=BGqFA2CMl9xWunUKLSO+HwKNphtURFM+Fl9YzPe/ZH/5N30gHqfM7gVCReAg0wa2wb g7mJMp+Gssk+pe6MUIRtB/fdzrRGnvi2uyqfe9NX3NW4OaoCFMkbsxMfqBDmvGlXAk9G vCgnEuY5PgwIFepgtmoQAWpDKsHihQYI2rfdflB9lVr43kqjBYmhFl3snLslYzyQxyl2 qzdXgMiYYGFOwsTN6WqXzobd6VvGK5J43aXq1f93cN9sDaMyQnwvRAkEKB1lIMCML5Ql KelSvzgJ+pi1pizyEhr5lj518m+9S3c3Iz05+fyx9LZS9bY246UKzIKo4aDPf5mQznWo ftJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790187262; x=1790792062; 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=9vdBhccq/94gqQzrXMG/7AB+kInwb5J5Iuo7pDxt+Tw=; b=F01ZL2pVZanXdISJbYzTJRubuB6CLSOt7fm/NttGGv4nFPHa+Y/efBtQLF8JX7JkNh E47TatJVVs+Q9FIItXIlPcrYO9fVbm7q9MGQmB0qYj04uyp4AmpJ8a7KsALnuQpKZC9m 1FUofJYnEv9UuZhhl1RpC7iUKqz6S0zvDt7335RwNDmgGtWY/ABdcXkOsa46bkR5rkNR CEzb0oDS5rCt2oBZq8EbLmUvPWamUOvZCRxWoKMixXaDWZPV4nfNa5bktwSbiVozeQXB LlJBmL3ACr0Y8eI/TNsjb4iF7uwLmJfU56mKsQyMiCQPMqBwtBJzK/SxJCiKtZY/hSQ5 svJw== X-Forwarded-Encrypted: i=1; AKwUvBw+vPsL9syo92/nOpiGpfcJCo8t9tjekux2VRIVlFc9d8pMsCE3+9x0B0gVC2xpDgGhtTIzzsYeRRqd3Q4=@vger.kernel.org X-Gm-Message-State: AFuF++kjnA1i69vNQwutoq92MexnGquHcn34ZyhCwj2lVic3/piPhlfW JI6R7RBjH1lfqaKAKWdQX9w3FJdpfWgJlW3tBru1uc2h0BGbR9IZVsjm3J2Zral9bJBOAqZ8Jpt 31f+I15kcXg== X-Received: from dleb14-n2.prod.google.com ([2002:a05:701b:424e:20b0:144:d0d2:bf01]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:3c87:b0:144:ee3d:21f6 with SMTP id a92af1059eb24-144f8dfce71mr2990008c88.16.1790187261495; Wed, 23 Sep 2026 11:14:21 -0700 (PDT) Date: Wed, 23 Sep 2026 11:11:52 -0700 In-Reply-To: <20260923181213.3032038-1-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> X-Mailer: git-send-email 2.56.0.rc1.310.g51773c2048-goog Message-ID: <20260923181213.3032038-30-irogers@google.com> Subject: [PATCH v3 29/49] perf python: Port rwtop from Perl to perf module From: Ian Rogers To: irogers@google.com, acme@kernel.org, alice.mei.rogers@gmail.com, 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, 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 rwtop.pl with a standalone Python script in tools/perf/python/rwtop.py using the perf Python module. Improvements compared to the legacy Perl script: - Remove the dependency on libperl and Perf::Trace::Util. - Support both offline perf.data files (via perf.session) and live recording (via LiveSession with --live), driving periodic interval summaries from event timestamps rather than wall-clock SIGALRM timers so both live and offline runs produce deterministic output. - 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. - Sanitize non-printable characters in /proc//comm to prevent terminal control sequence injection. Add a shell test (test_rwtop_python.sh) to verify the standalone script. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- tools/perf/python/rwtop.py | 256 ++++++++++++++++++++ tools/perf/tests/shell/test_rwtop_python.sh | 74 ++++++ 2 files changed, 330 insertions(+) create mode 100755 tools/perf/python/rwtop.py create mode 100755 tools/perf/tests/shell/test_rwtop_python.sh diff --git a/tools/perf/python/rwtop.py b/tools/perf/python/rwtop.py new file mode 100755 index 000000000000..9a66f37080ef --- /dev/null +++ b/tools/perf/python/rwtop.py @@ -0,0 +1,256 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Periodically displays system-wide r/w call activity, broken down by pid.""" +from __future__ import annotations + +import argparse +from collections import defaultdict +import os +import sys +from typing import Optional, Dict, Any +import perf +from perf_live import LiveSession + +class RwTop: + """Periodically displays system-wide r/w call activity.""" + def __init__(self, interval: int = 3, nlines: int = 20) -> None: + self.offline = False + self.interval_ns = interval * 1000000000 + self.nlines = nlines + 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.comm_cache: Dict[int, str] = {} + self.session: Optional[perf.session] = None + self.last_print_time: int = 0 + + def get_comm(self, pid: int, tid: Optional[int] = None) -> str: + """Resolve and cache the comm(and) of a pid.""" + comm = None + if self.session: + # In offline mode, query session.find_thread() directly so PERF_RECORD_COMM + # updates after execve are reflected immediately instead of returning a + # stale pre-exec comm from comm_cache. + try: + thread = (self.session.find_thread(pid, tid) + if tid is not None else self.session.find_thread(pid)) + comm = thread.comm() if thread else None + except (TypeError, AttributeError): + pass + if not comm: + comm = self.comm_cache.get(pid) + else: + comm = self.comm_cache.get(pid) + if comm: + return comm + try: + with open(f"/proc/{pid}/comm", "r", encoding="utf-8", errors="replace") as f: + comm = f.read().strip() + except OSError: + # The thread may have exited before /proc could be read. + pass + if not comm: + comm = f"PID({pid})" + comm = ''.join(c if c.isprintable() else '?' for c in comm) + self.comm_cache[pid] = comm + return comm + + 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 + sample_time = sample.sample_time + + if self.last_print_time == 0: + self.last_print_time = sample_time + + # Check if interval has passed + if sample_time > self.last_print_time and sample_time - self.last_print_time >= self.interval_ns: + self.print_totals() + self.last_print_time = sample_time + + # Map each event onto the totals it updates. "enter" events count the + # requested bytes, "exit" events the transferred bytes or the error. + handlers = { + "syscalls:sys_enter_read": (self.reads, "total_reads", None), + "syscalls:sys_exit_read": (self.reads, None, "bytes_read"), + "syscalls:sys_enter_write": (self.writes, "total_writes", None), + "syscalls:sys_exit_write": (self.writes, None, "bytes_written"), + } + handler = handlers.get(event_name) + if not handler: + self.unhandled[event_name] += 1 + return + + totals, count_key, bytes_key = handler + try: + value = sample.count if count_key else sample.ret + except AttributeError: + self.unhandled[event_name] += 1 + return + + data = totals[pid] + data["comm"] = self.get_comm(pid, getattr(sample, "sample_tid", None)) + if count_key: + data["bytes_requested"] += value + data[count_key] += 1 + elif bytes_key: + # Convert unsigned 32-bit or 64-bit kernel error 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 value > 0: + if 0xfffff000 <= value <= 0xffffffff: + value -= 0x100000000 + elif value >= 0x8000000000000000: + value -= 0x10000000000000000 + if value >= 0: + data[bytes_key] += value + else: + data["errors"][value] += 1 + + def print_totals(self) -> None: + """Print summary tables.""" + if not self.offline: + print('\x1b[H\x1b[2J', end='') + print("read counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# reads':>10s} " + f"{'bytes_req':>10s} {'bytes_read':>10s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*10} {'-'*10}") + + count = 0 + 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']:10d} {data['bytes_read']:10d}" + ) + count += 1 + if count >= self.nlines: + break + + print("\nfailed reads 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.reads.items(): + for error, cnt in data["errors"].items(): + errcounts.append((pid, data["comm"], error, cnt)) + + sorted_errcounts = sorted(errcounts, key=lambda x: x[3], reverse=True) + for pid, comm, error, cnt in sorted_errcounts[:self.nlines]: + print(f"{pid:6d} {comm:<20s} {error:7d} {cnt:10d}") + + print("\nwrite counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# writes':>10s} " + f"{'bytes_req':>10s} {'bytes_written':>13s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*10} {'-'*13}") + + count = 0 + 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']:10d} {data['bytes_written']:13d}" + ) + count += 1 + if count >= self.nlines: + break + + 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, cnt in data["errors"].items(): + errcounts.append((pid, data["comm"], error, cnt)) + + sorted_errcounts = sorted(errcounts, key=lambda x: x[3], reverse=True) + for pid, comm, error, cnt in sorted_errcounts[:self.nlines]: + print(f"{pid:6d} {comm:<20s} {error:7d} {cnt:10d}") + + # Reset counts + self.reads.clear() + self.writes.clear() + self.comm_cache.clear() + + 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 + + # Print final totals if there are any left + if self.reads or self.writes: + self.print_totals() + + 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 main() -> None: + """Main function.""" + parser = argparse.ArgumentParser(description="Trace r/w activity by PID") + parser.add_argument( + "interval", type=int, nargs="?", default=3, help="Refresh interval in seconds" + ) + parser.add_argument("-i", "--input", default="perf.data", help="Input file") + parser.add_argument("-l", "--live", action="store_true", help="Run in live mode") + args = parser.parse_args() + + analyzer = RwTop(args.interval) + try: + if args.live or (not os.path.exists(args.input) and args.input == "perf.data"): + # Live mode + events = ( + "syscalls:sys_enter_read,syscalls:sys_exit_read," + "syscalls:sys_enter_write,syscalls:sys_exit_write" + ) + live_session = LiveSession(events, sample_callback=analyzer.process_event) + print("Live mode started. Press Ctrl+C to stop.", file=sys.stderr) + live_session.run() + else: + analyzer.offline = True + analyzer.run(args.input) + except IOError as e: + print(e, file=sys.stderr) + sys.exit(1) + except KeyboardInterrupt: + if not analyzer.offline: + print("\nStopping live mode...", file=sys.stderr) + if analyzer.reads or analyzer.writes: + analyzer.print_totals() + +if __name__ == "__main__": + main() diff --git a/tools/perf/tests/shell/test_rwtop_python.sh b/tools/perf/tests/shell/test_rwtop_python.sh new file mode 100755 index 000000000000..062fca2dad14 --- /dev/null +++ b/tools/perf/tests/shell/test_rwtop_python.sh @@ -0,0 +1,74 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# rwtop 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}/rwtop.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, rwtop.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=$(mktemp /tmp/perf.out.XXXXXX) + +echo "Testing rwtop.py..." + +# Create a perf.data file. Try to get tracepoint data. +if perf list | grep -q "syscalls:sys_enter_read"; then + ev="syscalls:sys_enter_read,syscalls:sys_exit_read" + ev="${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}" > "${temp_out}"; then + echo "rwtop.py test failed" + err=1 +else + if ! grep -E -q "^ *[0-9]+" "${temp_out}"; then + echo "Failed to find metric data rows" + err=1 + else + echo "rwtop test passed." + fi +fi +rm -f "${temp_out}" + +exit $err -- 2.56.0.rc1.310.g51773c2048-goog