From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) (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 D3D5C35C691 for ; Mon, 21 Sep 2026 05:08:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789967308; cv=none; b=TIzALJkIDqqFC81E7raNMT+7pFVGRepup8jJZlxsoEGknAs40mpQo99NEF+Fb5nEsUKduoRKqBO7T5wMgqiG2RrUb8s5OJhawHz96lsrQ0dvJfm/JoJeJNo8ohVK6Q5Q2swhNRjUZ5HzdAPz9kQ/93FLDCTKD307LUT+Hs/+l8c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789967308; c=relaxed/simple; bh=xcIaJw+w15sD+EroYPe7dMNl7jlwwNzXMBBOmNAING8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=oIReQwP31iVCnkYsz2/e8h2/JC81H1JUgBI9Xz5JqcG2X+JTgU3HN2uzxKCRGxNwE/pm9yjgnX5Om9R56JIlB3tSC3TfpQVzkYReFte3jd5s7yMar2ytfKkI6QgHrRboZ7cRwHHNy8byl2dvMc0vqu2HC8x6L0tMM5i76H0D7pI= 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=W5aGg+ek; arc=none smtp.client-ip=209.85.216.71 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="W5aGg+ek" Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-38e1118e4abso4838248a91.0 for ; Sun, 20 Sep 2026 22:08:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789967305; x=1790572105; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=KHbcK54ZX6Nt0N4xNmcJtKZZeZv78jFOS9YGo8xcRJE=; b=W5aGg+ekliuxJnqqAwIk37Mk66inx1kK5Ixdi2eEo3N1eSOU8noUY1cDamhJP3jc/Q uC+rwEoGjAeuCzO8JzvtgISHI2DF/XYmQdKnJvTSHNNwJuAdQKvnNScLjNV4vfCdRcmZ pZPdjNGpN3pGgSb5YbDeR+Ltaj8K1JXLoDuw+5UchhTdna2LSBxYou1N0KK/W+wGNc1F oeb0tidvGBta161a7Hwz+AMLbzPIHUXQN6s7NmPGzIa2LQemonha2hQrjsgKrChlSS4+ ZmTNb7xUuDTiaizBycDtJLrija1yQje6EeG0anjezn4O1ArXZN+/WgTVQqQghuw+vrS4 WvdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789967305; x=1790572105; h=content-type: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:content-type; bh=KHbcK54ZX6Nt0N4xNmcJtKZZeZv78jFOS9YGo8xcRJE=; b=iaGwhTj30irF9AL6HnlGxbK6H+uBv8DnbMWbTJEzQ+ZI4TojA//4WDNxF7kIbPKsGO bqPuQFhufxzTa5yExhLbJoiM2PUqjiPl2+Se156wNnPV7geNl20pwoig/J9pi8QVoeCo DP2Ug6xs3kfvro5r0dHsVVtb8+nrVVFUqBckIDsIFtsDv7oeMvURN7Q4j55LFb1Q48kv dylAp6FmkMSr9lBXJK6Dqb1K3kVgNfErCP9VHyaZ7WUzADJJ3gd27K+443gqccmSCeMu sbwnmPrGXZk4Aaxydx7CnJFHy06lqP3RgtBPi2RJe4633GAFXDYvS3xmDpMs8Msa9gmq DeEw== X-Forwarded-Encrypted: i=1; AKwUvBzkJXePHv559BjfZI5yDOIFC/Tv4Ce4VlP15mnG4OBXmJrPzBDYRfIixySm+uBMNokpDU05BDXNNYszCIM=@vger.kernel.org X-Gm-Message-State: AFuF++nMD7srZdSIqqpWGqJL0FZ1Uk6aW21qzO0q+bJlDM3bx08wY9xt LkO1KExlY+h0UmkYiVGIz06jnEiTmRsKrawY7sAVNdp9PjzFmmbt/C+YQNLvoVqjXIzix1S8fC/ aT90SEMKiSA== X-Received: from dlep2-n2.prod.google.com ([2002:a05:701b:4582:20b0:144:c32a:6a84]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5903:b0:39e:d36c:ee54 with SMTP id 98e67ed59e1d1-39ed36cef6amr8101541a91.5.1789967304884; Sun, 20 Sep 2026 22:08:24 -0700 (PDT) Date: Sun, 20 Sep 2026 22:06:53 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Message-ID: Subject: [PATCH v2 35/49] perf python: Port net_dropmonitor to perf module From: Ian Rogers To: irogers@google.com, acme@kernel.org, alice.mei.rogers@gmail.com, linux-perf-users@vger.kernel.org, namhyung@kernel.org Cc: adrian.hunter@intel.com, dapeng1.mi@linux.intel.com, james.clark@linaro.org, leo.yan@linux.dev, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, tmricht@linux.ibm.com Content-Type: text/plain; charset="UTF-8" Port net_dropmonitor.py from tools/perf/scripts/python/ to a standalone script in tools/perf/python/: - Refactor the script into a DropMonitor class with full type annotations to encapsulate state. - Use perf.session for skb:kfree_skb event processing and add argparse CLI support (-i/--input and -k/--kallsyms). - Resolve kernel drop addresses via perf.session symbols/callchains and binary search over /proc/kallsyms, ignoring zeroed kptr_restrict addresses with graceful fallback when kallsyms is unavailable. - Remove Python 2 compatibility code. Add a shell test (test_net_dropmonitor_python.sh) to verify the standalone script. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- tools/perf/python/net_dropmonitor.py | 163 ++++++++++++++++++ .../shell/test_net_dropmonitor_python.sh | 103 +++++++++++ 2 files changed, 266 insertions(+) create mode 100755 tools/perf/python/net_dropmonitor.py create mode 100755 tools/perf/tests/shell/test_net_dropmonitor_python.sh diff --git a/tools/perf/python/net_dropmonitor.py b/tools/perf/python/net_dropmonitor.py new file mode 100755 index 000000000000..8c6b928651da --- /dev/null +++ b/tools/perf/python/net_dropmonitor.py @@ -0,0 +1,163 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0 +""" +Monitor the system for dropped packets and produce a report of drop locations and counts. +Ported from tools/perf/scripts/python/net_dropmonitor.py +""" +from __future__ import annotations + +import argparse +from collections import defaultdict +import os +import sys +from typing import Tuple +import perf + + +class DropMonitor: + """Monitors dropped packets and aggregates counts by location.""" + + def __init__(self, kallsyms_path: str | None = None) -> None: + self.drop_log: dict[int, int] = defaultdict(int) + self.kallsyms: list[Tuple[int, str]] = [] + self.kallsyms_parsed = False + self.resolved_syms: dict[int, Tuple[str, int]] = {} + self.callchain_syms: dict[int, str] = {} + self.kallsyms_path = ( + kallsyms_path + or os.environ.get("PERF_SYMBOL_KALLSYMS") + or "/proc/kallsyms" + ) + + def _parse_kallsyms(self) -> None: + """Parse the kallsyms file and map kernel addresses to function symbols.""" + self.kallsyms.clear() + self.kallsyms_parsed = True + try: + with open(self.kallsyms_path, "r", encoding="utf-8") as f: + for line in f: + parts = line.split() + if len(parts) >= 3 and parts[1] in ('t', 'T', 'w', 'W'): + addr = int(parts[0], 16) + if addr > 0: + self.kallsyms.append((addr, parts[2])) + self.kallsyms.sort(key=lambda x: x[0]) + except (FileNotFoundError, PermissionError): + print(f"Failed to read {self.kallsyms_path}. Symbols will not be resolved.") + + def _get_sym(self, loc: int) -> Tuple[str, int]: + """Resolve a memory location using session symbols or the kallsyms map.""" + if loc in self.resolved_syms: + return self.resolved_syms[loc] + if not self.kallsyms: + if loc in self.callchain_syms: + return self.callchain_syms[loc], 0 + return str(loc), 0 + + start = 0 + end = len(self.kallsyms) - 1 + while start < end: + mid = (start + end) // 2 + if self.kallsyms[mid][0] <= loc < self.kallsyms[mid+1][0]: + start = mid + break + if loc < self.kallsyms[mid][0]: + end = mid - 1 + else: + start = mid + 1 + + sym_addr, sym_name = self.kallsyms[start] + if loc >= sym_addr: + res = (sym_name, loc - sym_addr) + self.resolved_syms[loc] = res + return res + if loc in self.callchain_syms: + res = (self.callchain_syms[loc], 0) + self.resolved_syms[loc] = res + return res + return str(loc), 0 + + def print_drop_table(self) -> None: + """Print aggregated results.""" + if not self.drop_log: + print(f"{'LOCATION':>25} {'OFFSET':>25} {'COUNT':>25}") + return + + if not self.kallsyms_parsed and len(self.resolved_syms) < len(self.drop_log): + print("Gathering kallsyms data") + self._parse_kallsyms() + + print(f"{'LOCATION':>25} {'OFFSET':>25} {'COUNT':>25}") + sorted_keys = sorted(self.drop_log.keys()) + for sloc in sorted_keys: + sym, off = self._get_sym(sloc) + print(f"{sym:>25} {off:>25d} {self.drop_log[sloc]:>25d}") + + def process_event(self, sample: perf.sample_event) -> None: + """Process a single sample event.""" + if "skb:kfree_skb" not in str(sample.evsel): + return + + location = getattr(sample, "location", None) + if location is not None: + self.drop_log[location] += 1 + if location not in self.resolved_syms: + if getattr(sample, "sample_ip", 0) == location and getattr(sample, "symbol", None): + self.resolved_syms[location] = ( + sample.symbol, + getattr(sample, "sym_offset", 0) or 0, + ) + else: + for entry in getattr(sample, "callchain", []) or []: + if isinstance(entry, dict): + entry_ip = entry.get("ip") + entry_sym = entry.get("sym") + sym_name = ( + entry_sym.get("name") if isinstance(entry_sym, dict) else None + ) + sym_start = ( + entry_sym.get("start") + if isinstance(entry_sym, dict) + else None + ) + else: + entry_ip = getattr(entry, "ip", None) + entry_sym = getattr(entry, "sym", None) + sym_name = ( + getattr(entry_sym, "name", None) + or getattr(entry, "symbol", None) + ) + sym_start = getattr(entry_sym, "start", None) + if entry_ip == location and sym_name: + if sym_start is not None: + self.resolved_syms[location] = ( + sym_name, + max(0, location - sym_start), + ) + else: + self.callchain_syms[location] = sym_name + break + + +if __name__ == "__main__": + ap = argparse.ArgumentParser( + description="Monitor the system for dropped packets and produce a " + "report of drop locations and counts.") + ap.add_argument("-i", "--input", default="perf.data", help="Input file name") + ap.add_argument("-k", "--kallsyms", default=None, + help="Path to kallsyms file for offline symbol resolution") + args = ap.parse_args() + + monitor = DropMonitor(kallsyms_path=args.kallsyms) + + try: + session = perf.session(perf.data(args.input), sample=monitor.process_event, + kallsyms=args.kallsyms) + session.process_events() + except KeyboardInterrupt: + print("\nStopping trace...") + except (OSError, ValueError, KeyError, RuntimeError, TypeError, AttributeError) as e: + print(f"Error processing events: {e}") + sys.exit(1) + + monitor.print_drop_table() diff --git a/tools/perf/tests/shell/test_net_dropmonitor_python.sh b/tools/perf/tests/shell/test_net_dropmonitor_python.sh new file mode 100755 index 000000000000..41497f9837cf --- /dev/null +++ b/tools/perf/tests/shell/test_net_dropmonitor_python.sh @@ -0,0 +1,103 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# net_dropmonitor python test + +set -e + +shelldir=$(dirname "$0") +# shellcheck source=lib/setup_python.sh +. "${shelldir}"/lib/setup_python.sh + +if ! "$PYTHON" -c 'import perf' > /dev/null 2>&1; then + echo "Skipping test, perf python module not found" + exit 2 +fi + +script_dir="$(dirname "$0")/../../python" +script_path="${script_dir}/net_dropmonitor.py" + +if ! perf check feature -q libtraceevent > /dev/null 2>&1; then + echo "Skipping test, libtraceevent is disabled" + exit 2 +fi + + +if [ ! -f "$script_path" ]; then + echo "Skipping test, net_dropmonitor.py not found at $script_path" + exit 2 +fi + +err=0 +temp_data="" +temp_out="" + +cleanup() { + rm -f "${temp_data}" "${temp_out}" +} +trap 'cleanup' EXIT +trap 'cleanup; exit 1' TERM INT + +temp_data=$(mktemp /tmp/perf.data.XXXXXX) +temp_out=$(mktemp /tmp/perf.out.XXXXXX) + +echo "Testing net_dropmonitor.py..." + +# Create a perf.data file. Force dropping a packet if tracepoint is available! +if ! perf record -e skb:kfree_skb -o "${temp_data}" -a \ + -- ping -c 1 255.255.255.255 >/dev/null 2>&1; then + if ! perf record -e skb:kfree_skb -o "${temp_data}" \ + -- sleep 0.1 >/dev/null 2>&1; then + if ! perf record -o "${temp_data}" -- uname >/dev/null 2>&1; then + echo "Skipping test, cannot record perf events" + exit 2 + fi + fi +fi + +if [ ! -s "${temp_data}" ]; then + echo "Skipping test, perf record failed to create data" + exit 2 +fi + +# Check that the script executes and outputs table header +if ! "$PYTHON" "$script_path" -i "${temp_data}" > "${temp_out}"; then + echo "net_dropmonitor.py test failed" + err=1 +else + if ! grep -q "LOCATION.*OFFSET.*COUNT" "${temp_out}"; then + echo "Failed to find the metrics table header" + err=1 + fi +fi + +# Verify DropMonitor event processing and symbol resolution +if [ $err -eq 0 ]; then + if ! "$PYTHON" -c " +import sys +sys.path.insert(0, '${script_dir}') +import net_dropmonitor + +class DummySample: + evsel = 'skb:kfree_skb' + location = 0xffffffff81001010 + sample_ip = 0xffffffff81001010 + symbol = 'ip_rcv_finish' + sym_offset = 16 + callchain = [] + +dm = net_dropmonitor.DropMonitor() +dm.process_event(DummySample()) +dm.print_drop_table() +" > "${temp_out}"; then + echo "net_dropmonitor.py unit test failed" + err=1 + elif ! grep -q "ip_rcv_finish.*16.*1" "${temp_out}"; then + echo "Failed to find expected symbol resolution in net_dropmonitor.py" + err=1 + else + echo "net_dropmonitor test passed." + fi +fi +rm -f "${temp_out}" + +exit $err -- 2.55.0.1082.g2b9226bbc0-goog