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 D2E28392C21 for ; Sat, 25 Apr 2026 22:45:18 +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=1777157120; cv=none; b=JbRRp2lgfgwnT+sYczJwZJIJTx4iIIblEVV3ccjHHaMIyhso+xVcvzSjn+bt2dXQ3LDn6WQRTCwW8xPzMyLhGkgN4rlWXNZH9BVC3S9HytNspZBsydeFAFKZOze7cvzTqGv0rlaz6q1aKNH02PogcSGIeK6HLYalTXpo02MGupk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777157120; c=relaxed/simple; bh=j+1DPJ7hHqMkCRtiNL7ZTTuDpfoCTqlYLmFWD1lm5jM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=mDKQSMuZqmzYAnr9oYARuopzAHJZlDh2NRT/R1YsuHWUgYWC76jVRAwn3dW7vwxsmokqF+13mmbFpsHr1IYSPeqhnLNwynRk+VbrkxKw2A6uVAoN6R+tBJPFSnrOvFzLo+XwarYeXuvnKd3+1pEE3vUTuOro2Jy4zt9hhuWSS7E= 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=oaEcY6Sf; 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="oaEcY6Sf" Received: by mail-dy1-f201.google.com with SMTP id 5a478bee46e88-2d93379001eso20013667eec.1 for ; Sat, 25 Apr 2026 15:45:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777157118; x=1777761918; 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=Z8uDU0iX99Tgv3o+fYqZ9yp1w2za7K0HbBrM8LxB5IA=; b=oaEcY6Sf1fOjW2wcWjhGBC5uILQInmvN724GbAZ4egnB//y9S4QTVbGSz5EsZS1znr mwPizBSHzJpG3cEMonbn8yr40Bm76KpT3zwNhZE+02yYbbd+r0RjH1nwQLvjCRqm755K 2XPtuCe9QeE0GtibA6jADsnOLyqBRz9oV2WbkyBI92eUwq6HfIbYBxHocUkVNCKQyyt/ +4y3BMrzvgHibmMhMiXvkCoA7XOCvJTLH5xXI5zX/R8CyuonWoMRF0FTshjO/yjX7GI0 dKkesp44rFngw7nMIm+H/2ohhXwgthe7aeMsOkT5QkzVAlD6TGbgBv1eESy2S8Dqg52G 8g/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777157118; x=1777761918; 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=Z8uDU0iX99Tgv3o+fYqZ9yp1w2za7K0HbBrM8LxB5IA=; b=UdEFQkjTCZELt8EA0LT2K74iXB9BEL4ZVcSgAlwvj6AoHg5dF+jedYXX4RgiFqrmcL tgVAe9Jl7sZJ9N9390USejbBmhJBuKJ1/NgU2nJk6wzalCJw/Q9+5YnZFcMjdYOuG+Eh baTtnnQ16ttmMlAZaLgctmOiAtViUtVx8pLvlR6xIHralJuf/9sbeJpN2euVkZW1pWv6 TOyYLwLrB2wH65/5/Amt+/IukN+dZhykoSCNTOaioNe7o6HhfV1ZDrM2GGAh1RThDPp5 gG0CCBizfNftKCkXLRB5ey9SuWoq9FAe/FHp8RCqOiVYLNTukNzuTyRJeNhHbJmJF88S NK7g== X-Forwarded-Encrypted: i=1; AFNElJ/2vxj+gCEZxw7Kal7sWuihLVVT9gH06j48bWcadSwIV03ZHLysbKy1B9hfyHS22OnDdtgPbqfvS1tuTmk9+4yM@vger.kernel.org X-Gm-Message-State: AOJu0YzJ8/14TlTgRvvdjGLYoTc4LOMwNtY12bzi+jm74/my4DLTI93h +p13sTewh8DjVOEUMFcTsDyQWYVcA/WB1OLmZhAm01y07HCOijNMlifLsS/dYvhADCkn6DCMTPj Pb8URrPF+ow== X-Received: from dybss20.prod.google.com ([2002:a05:7301:7214:b0:2e5:ce71:32c4]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7300:2327:b0:2d8:97d6:6ac8 with SMTP id 5a478bee46e88-2e478c1ff0cmr23453474eec.21.1777157117979; Sat, 25 Apr 2026 15:45:17 -0700 (PDT) Date: Sat, 25 Apr 2026 15:44:52 -0700 In-Reply-To: <20260425224503.170337-1-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> <20260425224503.170337-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260425224503.170337-6-irogers@google.com> Subject: [PATCH v7 48/59] 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. v6: - Fixed `AttributeError` by using `str(sample.evsel)` to get event name. --- 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..2103ac0412bb --- /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 = 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 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