From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f201.google.com (mail-dy1-f201.google.com [74.125.82.201]) (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 968353B0AD6 for ; Sat, 25 Apr 2026 22:51:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777157519; cv=none; b=cykGp7UbYmBSkU0UHTpuWFdCLPaMc9WA2XkcJQ7+Pjs+9Bgn5OIx2SBtBgx4LtO8IwUyAJ+iEkUzrFnOAuSdPWiNwh/xRVzAAs9evluRkVxKIANcSR7F1amO9Hz9tZ3nDxWc5R6R5KVMo4KI02pP6Qkzmchy5NeiUAOMn9U6/OA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777157519; c=relaxed/simple; bh=bZNdf2xRLALfsVIlIhihnaH+uaJBxWazbnpkNK5OY24=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ssNdIDWcKH4WIGvj+FrdW8PWxzCq2sXY45OiIOCXpkPkV1lo+rAWfRkWvuAaubGPT4VzoaOB/8YE5/6O54k9aX++bdbA7lpqUqUNYwnHaNaIFk/wPJtBu3QdyOFsQEJyZewkmxoCl4FQFARrqsd+puXbF634jyv6DtRm/kVrEY0= 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=T0BOLsaf; arc=none smtp.client-ip=74.125.82.201 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="T0BOLsaf" Received: by mail-dy1-f201.google.com with SMTP id 5a478bee46e88-2cc75e79b97so24550681eec.1 for ; Sat, 25 Apr 2026 15:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777157516; x=1777762316; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=qbPEhnMlYjLIyQYaNXILQynFaRfheBD/Hl8QlXDxSqM=; b=T0BOLsaf/pXz5V055Ax6kJv7LJAAHjUTSvl8Glz8TNpRAcDbZU9kMaV04nx5kd1o2l W3UDc/dlSRdVwVtCSiXU2l1V8cMltWx2JzkuoRfEZ/US/F8FMSbt2XnaCL8aE/wbU/0/ psGChY1LzP949E5/r03qnnZIHBoYrvQpIbv5ySRfXqHosywE/acnRrki+iT3VaVxtz9R aDdbjKyA81iyQV3hzYJ03HcKz7j0h0LYRVO3tR+CGB9EkS1Gf11j2QoUpcNQ0fehDqKb JaDNvFrQCT1wFHYw21avDYzCSW/LSykZz0JybrdauLm/gRglkSZBNFUB51NACxLR7c2u gK/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777157516; x=1777762316; h=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; bh=qbPEhnMlYjLIyQYaNXILQynFaRfheBD/Hl8QlXDxSqM=; b=jQ+1/hCQb+HC0fIpUU2AtKqBDoRKht1XKVk8ET6VdPCjKRFQDemTyIadCK1zqgGgat EfHoQwX5Vgpfa3qkCnndMUZkXKChJgey9XmGxcfeYa3/CAyUtsYAPEKgUpqJ3UEVVdih KmYVqyMQWxbvedBPrlYQIoFHYVGUsmxD/HFyxexqL9+Wj/5V8F/vA7eBeMRofx/2vjiF X1i2KJtWU1sS/wE7Y7nn9ISIVuclkjqjfhUCYaf8HXlsRwbBQN2RZ+JgYhWgk3KdZnNg mKpzlK9xeDy6KFolGuoIxejRrlvwZq7n+GmggtNFDFT5Y4Jq1PkltPpGendkoZat27SE G+cA== X-Forwarded-Encrypted: i=1; AFNElJ9NmSkRh33JDLzHpxQbbUxffT3SuVqAU3Zaavebtux/kRHw0VDbfw84hO80Hq3fFlwrTYxFFuJaSWz0MeuJPfAP@vger.kernel.org X-Gm-Message-State: AOJu0Ywt35xrrFcR0T+OGKn1AT3aNqvykFQZ7MqSOwaayReuSIVsUl1V YjgxYXGAsNy6ipPcaS3GzJQ8FDQn7F95DHQxNujWfLjJRWdWpdWD8uzxN3cLJ4Mf0QQfM5moC02 2HCwQ1d0Jgw== X-Received: from dycol2.prod.google.com ([2002:a05:7301:db82:b0:2dd:8e19:2d13]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:693c:2b04:b0:2df:919f:ce59 with SMTP id 5a478bee46e88-2e47901614bmr20625177eec.19.1777157515734; Sat, 25 Apr 2026 15:51:55 -0700 (PDT) Date: Sat, 25 Apr 2026 15:49:41 -0700 In-Reply-To: <20260425224951.174663-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260425174858.3922152-1-irogers@google.com> <20260425224951.174663-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260425224951.174663-50-irogers@google.com> Subject: [PATCH v7 49/59] perf rw-by-pid: Port rw-by-pid to use python module From: Ian Rogers To: acme@kernel.org, adrian.hunter@intel.com, james.clark@linaro.org, leo.yan@linux.dev, namhyung@kernel.org, tmricht@linux.ibm.com Cc: alice.mei.rogers@gmail.com, dapeng1.mi@linux.intel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, Ian Rogers Content-Type: text/plain; charset="UTF-8" Port the legacy Perl script rw-by-pid.pl to a python script using the perf module in tools/perf/python. The new script uses a class-based architecture and leverages the perf.session API for event processing. It tracks read and write activity by PID for all processes, aggregating bytes requested, bytes read, total reads, and errors. Complications: - Refactored process_event to extract helper methods (_handle_sys_enter_read, etc.) to reduce the number of branches and satisfy pylint. - Split long lines to comply with line length limits. - pylint warns about the module name not being snake_case, but it is kept for consistency with the original script name. Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers --- v2: - Fixed Substring Matching: Replaced loose substring checks like if "sys_enter_read" in event_name: with exact matches against syscalls:sys_enter_read and raw_syscalls:sys_enter_read using sample.evsel.name . This prevents unrelated syscalls with similar names (like readahead ) from being incorrectly aggregated. Similar fixes were applied for exit events and write events. - Inlined Handlers and Tracked Errors: Inlined the _handle_sys_* helper methods into process_event() to make error handling easier. Now, if a sample lacks expected fields (raising AttributeError ), it is added to the self.unhandled tracker instead of being silently dropped, providing better visibility to the user. - Code Cleanup: Fixed trailing whitespace and added a pylint disable comment for too-many-branches caused by the inlining. v6: - Fixed `AttributeError` by using `str(sample.evsel)` to get event name. --- tools/perf/python/rw-by-pid.py | 158 +++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100755 tools/perf/python/rw-by-pid.py diff --git a/tools/perf/python/rw-by-pid.py b/tools/perf/python/rw-by-pid.py new file mode 100755 index 000000000000..b206d2a575cd --- /dev/null +++ b/tools/perf/python/rw-by-pid.py @@ -0,0 +1,158 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Display r/w activity for all processes.""" + +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_written": 0, + "total_writes": 0, + "comm": "", + "errors": defaultdict(int), + } + ) + self.unhandled: Dict[str, int] = defaultdict(int) + self.session: Optional[perf.session] = None + + def process_event(self, sample: perf.sample_event) -> None: # pylint: disable=too-many-branches + """Process events.""" + event_name = str(sample.evsel)[6:-1] + pid = sample.sample_pid + + assert self.session is not None + try: + comm = self.session.find_thread(pid).comm() + except Exception: # pylint: disable=broad-except + comm = "unknown" + + if event_name in ("syscalls:sys_enter_read", "raw_syscalls:sys_enter_read"): + 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[event_name] += 1 + elif event_name in ("syscalls:sys_exit_read", "raw_syscalls:sys_exit_read"): + try: + ret = sample.ret + if ret > 0: + self.reads[pid]["bytes_read"] += ret + else: + self.reads[pid]["errors"][ret] += 1 + except AttributeError: + self.unhandled[event_name] += 1 + elif event_name in ("syscalls:sys_enter_write", "raw_syscalls:sys_enter_write"): + try: + count = sample.count + self.writes[pid]["bytes_written"] += count + self.writes[pid]["total_writes"] += 1 + self.writes[pid]["comm"] = comm + except AttributeError: + self.unhandled[event_name] += 1 + elif event_name in ("syscalls:sys_exit_write", "raw_syscalls:sys_exit_write"): + try: + ret = sample.ret + if ret <= 0: + self.writes[pid]["errors"][ret] += 1 + except AttributeError: + self.unhandled[event_name] += 1 + 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 #':>6s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*6} {'-'*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:6d} {count:10d}") + + print("\nwrite counts by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'# writes':>10s} {'bytes_written':>15s}") + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*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} " + f"{data['total_writes']:10d} {data['bytes_written']:15d}" + ) + + print("\nfailed writes by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'error #':>6s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*6} {'-'*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:6d} {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) + self.session.process_events() + 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() -- 2.54.0.545.g6539524ca2-goog