From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 2F38E395250 for ; Sat, 25 Apr 2026 22:45:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777157123; cv=none; b=p0CcnEjtiez+DSti2UAHPAZyLStxL7lfgl58Y4vGbdIxXxkzDrJszmzjy+S00WwfiV7OgyeARBE2/eOa+1KpmCcdne+JIiu9q+NMP9I9iLl8VlN5XPVWhqnhIi8SGao2Y+iuVF6y8Vm4zllhgTydTMqGBaiptKKUtyB1J2DmJoY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777157123; c=relaxed/simple; bh=bZNdf2xRLALfsVIlIhihnaH+uaJBxWazbnpkNK5OY24=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=XhWT41vyTtEiY6DCWjqRy026wkwu1hIcaYihZ5hzbsC27+yfblNWl6O1Se12Ms3RBWS2lCzpcdaasz3RSc2Q0Cqhx+G3J7VV59WTfnKo6xPM0PO6W/jKgDOtNGjKnGpXusBpCdBqBw13+bZKeOW9MpmTAwKFmCRfcAaMEWmgSs4= 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=ZpuB2uHN; arc=none smtp.client-ip=209.85.216.73 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="ZpuB2uHN" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-35daf3d3030so9460932a91.1 for ; Sat, 25 Apr 2026 15:45:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777157120; x=1777761920; 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=ZpuB2uHNZ6pgJUVzLu3k5Uwj+/c/T+9guqkf8zyx1lUlH2xPVXHmOeL1gWx7O/wLwV qpeZZDpWWG4KUhTk+XViYj/NeegPQojZXLF8UE8qWqIymRe4OfyQPtEaBf3MxCInJxik GbBfw4PK+wh0a0Sa08xRST5K8OXUvX61U0QdbxLduhl69WbyH+9naE45U7I8fFU2S3XK HUY9J7T9Fr4+BqeIwbJVpL336cLyPiDlaytwqet1S9WaRK3bQqkaDtN76+hUOWynckBM 58SpVm9k6VwtyMXMsDzyPXoJk2GkRo0aATtGzFEdJm18fIaEttd45WQqGs//9irG6Pr3 P+Pg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777157120; x=1777761920; 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=UsOj+ALIKyklImUyhPjpWlXEoD9KDJ3odmR1ZfL1qFPc6DGpUUvDgAZDr+ZQqKFqpU Qg2gQcmVl5CGtjOjp5QEafbrGXuyKXTyciLP8i/gh8fq6GCld0lHdqQ6sCdyJ2PC58W8 kFIcqxURqNTeXbZFcl/xwfvLOvVmCh4my2ai10fZqwYYz7XGrzf0fgQ0DtIwKtdOwraf 4W9p4AANtuguEGiEF9EWUjSKO/t8MFHb5CjJRHRUh56qE8ofBCKaPg8YWTyzho0K/u1A S2tHQdfpAlfyG/qpyORvRrfkDf65iOFW6O2g0DA6ZhSBlGIxTz75HVGc4TQGXnzbJ0bC eNBg== X-Forwarded-Encrypted: i=1; AFNElJ+BRDPnBjoPu8krMRq7O4VZtNtkWDXWkr2McKu1wkK8FT95EZgexEop/Ylrm2WklGLhketWH1m2k7UFYa0=@vger.kernel.org X-Gm-Message-State: AOJu0Yxd7idOJ0SET00R2nRKp08KP2EoRxFd5ObBBfFLJeYLL+s4/EBj RPp8E4auOKND+BHKiIrG4mqhLHj5MyLo1/xpOGvNVMzz4vYlS0vCnGnuWBz2KgL4HCw6ssIZh36 9T8ctD1IQrg== X-Received: from pgbcq10.prod.google.com ([2002:a05:6a02:408a:b0:c76:a4b1:60cf]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:3949:b0:3a0:129a:973f with SMTP id adf61e73a8af0-3a08d8f28dcmr41625673637.52.1777157120117; Sat, 25 Apr 2026 15:45:20 -0700 (PDT) Date: Sat, 25 Apr 2026 15:44:53 -0700 In-Reply-To: <20260425224503.170337-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260425174858.3922152-1-irogers@google.com> <20260425224503.170337-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260425224503.170337-7-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