From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f73.google.com (mail-dl1-f73.google.com [74.125.82.73]) (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 E988440757C for ; Tue, 28 Apr 2026 07:20:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777360860; cv=none; b=QT6OammV9adu3sa5tOgtvXw+EGLGfiePki7sbM1YRShsbftcM21EDQXvgzDC/e7czqMcVKRNpZphCtrTWNuaNKu38hirAEubgSeSTAydiZElW6lSEd7HxO8SESrnwIqcK3pwoB427yjGERTU4/rhy3GcVV4jc4AaL9PgtYWFouU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777360860; c=relaxed/simple; bh=bZNdf2xRLALfsVIlIhihnaH+uaJBxWazbnpkNK5OY24=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Ur0gj7HS1Wl0+S5UCz2MuxzkZTphg1mVuvC406opka9LUdJ5QOV7l+EmvkdXsVx8dFQFwhwLkdyfj6PUi45IrEw+xck0ZUiIPdl0M+FyOM3p95iB9jI29+ISNL3sPRQr26XsrhVAJgkga4Rarvg5qjmADhH6zbZguzxSB2sKey0= 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=NFRXM54J; arc=none smtp.client-ip=74.125.82.73 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="NFRXM54J" Received: by mail-dl1-f73.google.com with SMTP id a92af1059eb24-12c8ccc7593so14029777c88.1 for ; Tue, 28 Apr 2026 00:20:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777360857; x=1777965657; 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=NFRXM54Jk5XiVippz2uVIwmwq5qmB8o4ZvcNGt6VcNuU/sK8b0TS2bo2wsAbiowES4 pfA3iPXIfDtwP13d2Sl3dBMqfnEsniTaIw3dhfEQlaM41jRqeB3jdbQo0UKFLhef4HaP KvY+dSVGMJfTDTWkbeyrlbQGXMt7i50nD8edMS0wdHiHFbwS5IaDR90mj3aY5tWx54al 6N41zSb8j880Glf18JVyCjvS6AAII9wn9fErfnvBkAo1cR7wR/XGZKV9mgp3NwgiWZlf 4yqJ2R8wZSk2UGBW924o2t/3fasd2KCQl4YdqeHa+bpMAHTtgybyxHPEipWNnt8HONiH d6QA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777360857; x=1777965657; 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=q/KDb8w4tIMRNitt6bwIIJD3z3sBXuQJnOp+AT2atg8gM0Mq9Q2dHpxQIgWmlBw4VX xzgKyfeRx8uZ7gUFreYPfiKvV2b738T3JikDd3xZkqw3EqYTmF8v75TbpLN/X5o2lp3w vJpsegtLVz7r5cMPdDbkUi9E9Q/eywKkyZcUgieIx5vK1x9YHEHmKt/hNVuotx4LnW8v 9PiTHHZe0tLRydu3NojmBI77AjXs5mRwusGljbTethBY6INO1CpeOiH3WRja9JvhHokN pjslZxrDzkAWuWoN6NQUdS7dxY7gXWHfOMOmKrpAKGGffNrBH6DIXr++ClBXd/E8yXOP yYZA== X-Forwarded-Encrypted: i=1; AFNElJ9IRWKGE+4jQ/UMpqrfBbdxozFvl64dwrGR4BLSC1pdNOSCZ/8A5FSdpakgNAVx6u+n3+fjGMbacOJ4XTdhEhYJ@vger.kernel.org X-Gm-Message-State: AOJu0YxkWc9EUPP8QFbxhnkb+wuP4XkvZjILXkUNo41BSUySzlZvLw2C RJleMIeHjgoap1a0dW/n+5Cfg95dbTnmh61fCH/H9MAmDy70QZQadj9IIavlIUPNd6oLcXjB7/V iOSkyZHNvyw== X-Received: from dlbto2.prod.google.com ([2002:a05:7022:3b02:b0:12d:c585:f600]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:6ba1:b0:12d:de3f:f3dc with SMTP id a92af1059eb24-12dde3ff91emr366117c88.38.1777360856946; Tue, 28 Apr 2026 00:20:56 -0700 (PDT) Date: Tue, 28 Apr 2026 00:18:54 -0700 In-Reply-To: <20260428071903.1886173-1-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: <20260425224951.174663-1-irogers@google.com> <20260428071903.1886173-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260428071903.1886173-50-irogers@google.com> Subject: [PATCH v8 49/58] perf rw-by-pid: Port rw-by-pid to use python module From: Ian Rogers To: acme@kernel.org, namhyung@kernel.org Cc: adrian.hunter@intel.com, alice.mei.rogers@gmail.com, dapeng1.mi@linux.intel.com, james.clark@linaro.org, leo.yan@linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, tmricht@linux.ibm.com, 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