From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f202.google.com (mail-dy1-f202.google.com [74.125.82.202]) (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 A1DA833E36A for ; Fri, 24 Apr 2026 16:49:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777049371; cv=none; b=H7e4K0zdwVqDeDmAic2//Ibh9prFCMk6C6hubiNK6LbrTNNZ0s1XRC6aRK7dK3T73mGWGAgoRtI9w9uZnCxI6UBgeAnvX0mWKzu9CHrR4G2LepF0w54K5QNIWU7sX94Qpg1ffSEC6pdglg+5T1jnWScNXuML91lskMZqanh1bVs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777049371; c=relaxed/simple; bh=bLVNpLi8urjvclamDOuNIS+Nsu9v6LV6hvcHr42wF74=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=sQeIP+r0MP0l9uxzjvvvLHEYtAkD2m0TeyVTNJaJAzXmh41mD5kMagUfdNjxVnXNdgCaxt7sr3hRrUz7BNtqNt4PjubeRi3yJu4jQDzfat6wzibvVuvK+xp491VzVbZxOH6xtL4PVpPTwbTZEaCOGLlS5rJyPnYtFWmYVXXBYbI= 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=c7JCqjDi; arc=none smtp.client-ip=74.125.82.202 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="c7JCqjDi" Received: by mail-dy1-f202.google.com with SMTP id 5a478bee46e88-2d9da2559aeso21252641eec.0 for ; Fri, 24 Apr 2026 09:49:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777049369; x=1777654169; 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=sdsIaZxORPBtHlF7NDydqw84ClDmIcXPteqzDGLLDeY=; b=c7JCqjDig4ihuvlAE3v2Ke2n3UbP5SjtGRIxaVAcwswKu9BFEOXMR5WVjfki15zNAQ bw/Egz2TEksw9N6YBpLAhLnx419YbhDQji5Fj1nBP8/EAPSacIOJHp8c19zDSx7ukYRK wW479TySjY1D26tafc+w1sCw+fYPHuPpjXu+5Jn8pBJAO/i7QPyoc23Us4/+QjCp0OCt uOR1s6ANfZXFgmGjr+mcFk66T1NO3mH7/HdUHKfA6Ft5ipS2gVbw8YdnJWZWg+PIhlg0 BXT0vhupZgd7p6YK8WzCBWjJ61U3V16nBnPdQW/cDsXLZ8Oj2LByYOQKjMp97EVTp85E K4NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777049369; x=1777654169; 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=sdsIaZxORPBtHlF7NDydqw84ClDmIcXPteqzDGLLDeY=; b=mHkMstBPL+vTzAG/A8icVNQrKA1WrZsjSAekUxHAM+osloJKVfB17/dI43SogqYZq6 W4kMrfdV8kTdIT6rWsn5I0KrrdvCAwPW1IwIsvRmVE3GK9/8NBvyEc+7jmve8hw05nl6 VyBI/bsaPKTe/d20wcT0eJ+czPk1/PMI8yec8ZaHmdDvCdvgZ4xAPSXjdsN30/7fWDAo E6RfvzKdIcjyT3r96nHErt74+rDVnMj9mqlRZvFpnrbXLp5V274216YjmTvONDKFVrxK X87+Ke2HKzjtfIKg2Q4GTnNV+veVaBocckAn6NA/0kS4xWETe6pfCE3gtDWrBd1u9mgl vpzQ== X-Forwarded-Encrypted: i=1; AFNElJ97S5/ULQZzmISdPa2V1SQYDrQAyP3t/89UCbHVscf/nVW6EvkFaS+OzRkYr5QmGchdIrPn/g7k1/FrkTU=@vger.kernel.org X-Gm-Message-State: AOJu0YxtL1TNDKhqUkz4DK7+4zdA40RUBjWVWVo06N67exw/qENhvbhd lbGwKODINxznqdFc8h057TWd9O2JqLVaGxC1m8s023KX0n8wjQA3UJXNvknSQVK32t+HpY7SHP1 RgOzw36ulXg== X-Received: from dycao4.prod.google.com ([2002:a05:7301:7d04:b0:2da:3d44:ddce]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:9f12:b0:2e1:e3e6:2910 with SMTP id 5a478bee46e88-2e46577039dmr20625261eec.9.1777049368506; Fri, 24 Apr 2026 09:49:28 -0700 (PDT) Date: Fri, 24 Apr 2026 09:47:11 -0700 In-Reply-To: <20260424164721.2229025-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260423163406.1779809-1-irogers@google.com> <20260424164721.2229025-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260424164721.2229025-50-irogers@google.com> Subject: [PATCH v5 49/58] 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. --- 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..53e16b373111 --- /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 = sample.evsel.name # type: ignore + pid = sample.sample_pid + + assert self.session is not None + try: + comm = self.session.process(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