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 690313ACF0F for ; Fri, 24 Apr 2026 16:49:27 +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=1777049370; cv=none; b=c4OkvO52Oz4VsfCnfZbiATngoquSMMcuTuj5TRM6TZwhWjids5JgOAF38qwGQc5nuEtQNpGnb40RNi6jpCVMxCVguC+dQW0UqBOQA8SeHT7pdXkiifzx+xMhdxPzqtSV4X28fRbiqt5QeqdmgawILAR11iqTIfc/juwvma5uG4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777049370; c=relaxed/simple; bh=1jHa4HYK0G7iZ5Loj9OlxNIyriBUkZMFKOg3o08CrTg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=A7ZU1DiGEGoa+gZB/Nv5V33lU9MEc4IsM6nge6fJGWMWTxQyJFMLxaj39cs3geMGc6JgJfBFK76E7EwCkNEYaPcC4iIgWi280SaCeFMfvRhfOLrMcXGgazQIIjTKLm5t+xytRx/qlGB+nmMF3TlXPbFter3cCFZpVkFyEjWgoVY= 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=dGy3ejVA; 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="dGy3ejVA" Received: by mail-dl1-f73.google.com with SMTP id a92af1059eb24-12c87ba0890so25327454c88.0 for ; Fri, 24 Apr 2026 09:49:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777049366; x=1777654166; 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=0Cc1jZjiNz6qIzGkr9ZYmlIDRLWz0J6P2q+qfe2/eFk=; b=dGy3ejVA0Z02w4qEPJ+H15uayou4uyn4p4kjYDgxVsW43dhS29KkpqweVGDjefexH1 wmCu35VPUZvI7o9kg1oKfyFmkKHRCn8vSphCYL97F69Dgww4t+Z0hn/WUn29Ov9uQxQO vYdWZ+XoizrN/NutJjIb7wQeRqQRI1CvHCDSTbxuKqg+/WdJr6yrpz/a+YwALezxUi04 GkbemhLhxI6hJvPf7v2P9rOb18/kuVPF7qgjKMJKoudxQXTz6W/IEUTeNvAyayruSN6C 0VIFjXyN0J5u9OVLsHkP/nZt+qMShaptB6MP/75nandgPGSZsV6sdSczql8VDslHrq+I Yd7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777049366; x=1777654166; 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=0Cc1jZjiNz6qIzGkr9ZYmlIDRLWz0J6P2q+qfe2/eFk=; b=GEJmyJT2wQUgxSRMpMjZRo+Y3da7TItEpdN2v2s6PJ4CEsq4V+Vn9/r9pNtlBH9Mlx ZE8Q4D37ckIxgZxP3i0/AvbSEkO0QFuTx0Lf3jbq5Ln2uiHXkVfKS3N4ysoDEJkXuHe6 ntxnzfAUYWH9mB6F6/sy5fx6hcDU/pmCggT9tA5c4pibNHjkxhimxWvPRYkrhzL1g64W kBcg94unn4vSOeuFi1P+u/k0MLhK3YIqXrya49aULyZf3Yqeks9dMn4aoRWRvxbHwP3G h0xH1wC9OiAw/l5RBrc7q8s4Cj/2dtiRdXpDlcXX72vIOt2KimCVMlWrbyB8uGGAH0i/ nblg== X-Forwarded-Encrypted: i=1; AFNElJ+ZQCp0k8tS8EQTSCwergDU4OrArjyvvEOhGhLvPcP0mxtDC+81qphT4SS0vHd9tz1bgMG3AAXoXKWEHS8=@vger.kernel.org X-Gm-Message-State: AOJu0YxPebnzqcmzCK6gwjoghY5YXHrozA/ccQ0UfCoxEu+DzYbF611t Q/AHrXmE5KNbZIBen+kQ0IzCBnq6SN4iE1B4Lfdxa7dL81nB2JI0kZ1hLH5j0vu4lhE9JL9lajn hHhMDv+m1IA== X-Received: from dlbpu10.prod.google.com ([2002:a05:7022:e88a:b0:12b:fba9:5eb0]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:4199:b0:12c:8b9:71db with SMTP id a92af1059eb24-12c73f97587mr18037107c88.21.1777049366351; Fri, 24 Apr 2026 09:49:26 -0700 (PDT) Date: Fri, 24 Apr 2026 09:47:10 -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: <20260424164721.2229025-49-irogers@google.com> Subject: [PATCH v5 48/58] perf rw-by-file: Port rw-by-file 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-file.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 file descriptor for a given program name, aggregating bytes requested/written and total counts. Complications: - Had to split long lines in __init__ to satisfy pylint. - 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 if "sys_enter_read" in event_name: with an exact match against syscalls:sys_enter_read and raw_syscalls:sys_enter_read using sample.evsel.name . This prevents variants like readv or readlink from incorrectly triggering the read logic. Similar fixes were applied for write events. - Fixed Silent Error Dropping: Instead of silently returning when expected fields are missing (causing AttributeError ), the script now increments the self.unhandled counter for that event. This ensures that missing data or unexpected event variants are reported to the user instead of quietly skewing the results. --- tools/perf/python/rw-by-file.py | 103 ++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100755 tools/perf/python/rw-by-file.py diff --git a/tools/perf/python/rw-by-file.py b/tools/perf/python/rw-by-file.py new file mode 100755 index 000000000000..f71e0b21f64e --- /dev/null +++ b/tools/perf/python/rw-by-file.py @@ -0,0 +1,103 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Display r/w activity for files read/written to for a given program.""" + +import argparse +from collections import defaultdict +import sys +from typing import Optional, Dict +import perf + +class RwByFile: + """Tracks and displays read/write activity by file descriptor.""" + def __init__(self, comm: str) -> None: + self.for_comm = comm + self.reads: Dict[int, Dict[str, int]] = defaultdict( + lambda: {"bytes_requested": 0, "total_reads": 0} + ) + self.writes: Dict[int, Dict[str, int]] = defaultdict( + lambda: {"bytes_written": 0, "total_writes": 0} + ) + self.unhandled: Dict[str, int] = defaultdict(int) + self.session: Optional[perf.session] = None + + def process_event(self, sample: perf.sample_event) -> None: + """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 comm != self.for_comm: + return + + if event_name in ("syscalls:sys_enter_read", "raw_syscalls:sys_enter_read"): + try: + fd = sample.fd + count = sample.count + self.reads[fd]["bytes_requested"] += count + self.reads[fd]["total_reads"] += 1 + except AttributeError: + self.unhandled[event_name] += 1 + elif event_name in ("syscalls:sys_enter_write", "raw_syscalls:sys_enter_write"): + try: + fd = sample.fd + count = sample.count + self.writes[fd]["bytes_written"] += count + self.writes[fd]["total_writes"] += 1 + except AttributeError: + self.unhandled[event_name] += 1 + else: + self.unhandled[event_name] += 1 + + def print_totals(self) -> None: + """Print summary tables.""" + print(f"file read counts for {self.for_comm}:\n") + print(f"{'fd':>6s} {'# reads':>10s} {'bytes_requested':>15s}") + print(f"{'-'*6} {'-'*10} {'-'*15}") + + for fd, data in sorted(self.reads.items(), + key=lambda kv: kv[1]["bytes_requested"], reverse=True): + print(f"{fd:6d} {data['total_reads']:10d} {data['bytes_requested']:15d}") + + print(f"\nfile write counts for {self.for_comm}:\n") + print(f"{'fd':>6s} {'# writes':>10s} {'bytes_written':>15s}") + print(f"{'-'*6} {'-'*10} {'-'*15}") + + for fd, data in sorted(self.writes.items(), + key=lambda kv: kv[1]["bytes_written"], reverse=True): + print(f"{fd:6d} {data['total_writes']:10d} {data['bytes_written']:15d}") + + 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 file") + parser.add_argument("comm", help="Filter by command name") + parser.add_argument("-i", "--input", default="perf.data", help="Input file") + args = parser.parse_args() + + analyzer = RwByFile(args.comm) + 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