diff options
Diffstat (limited to 'tools/perf/python/rwtop.py')
| -rwxr-xr-x | tools/perf/python/rwtop.py | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/tools/perf/python/rwtop.py b/tools/perf/python/rwtop.py new file mode 100755 index 000000000000..86674d7c8f6f --- /dev/null +++ b/tools/perf/python/rwtop.py @@ -0,0 +1,256 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +"""Periodically displays system-wide r/w call activity, broken down by pid.""" +from __future__ import annotations + +import argparse +from collections import defaultdict +import os +import sys +from typing import Optional, Dict, Any +import perf +from perf_live import LiveSession + +class RwTop: + """Periodically displays system-wide r/w call activity.""" + def __init__(self, interval: int = 3, nlines: int = 20) -> None: + self.offline = False + self.interval_ns = interval * 1000000000 + self.nlines = nlines + 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_requested": 0, + "bytes_written": 0, + "total_writes": 0, + "comm": "", + "errors": defaultdict(int), + } + ) + self.unhandled: Dict[str, int] = defaultdict(int) + self.comm_cache: Dict[int, str] = {} + self.session: Optional[perf.session] = None + self.last_print_time: int = 0 + + def get_comm(self, pid: int, tid: Optional[int] = None) -> str: + """Resolve and cache the comm(and) of a pid.""" + comm = None + if self.session: + # In offline mode, query session.find_thread() directly so PERF_RECORD_COMM + # updates after execve are reflected immediately instead of returning a + # stale pre-exec comm from comm_cache. + try: + thread = (self.session.find_thread(pid, tid) + if tid is not None else self.session.find_thread(pid)) + comm = thread.comm() if thread else None + except (TypeError, AttributeError): + pass + if not comm: + comm = self.comm_cache.get(pid) + else: + comm = self.comm_cache.get(pid) + if comm: + return comm + try: + with open(f"/proc/{pid}/comm", "r", encoding="utf-8", errors="replace") as f: + comm = f.read().strip() + except OSError: + # The thread may have exited before /proc could be read. + pass + if not comm: + comm = f"PID({pid})" + comm = ''.join(c if c.isprintable() else '?' for c in comm) + self.comm_cache[pid] = comm + return comm + + def process_event(self, sample: perf.sample_event) -> None: + """Process events.""" + event_name = str(sample.evsel) + if event_name.startswith("evsel(") and event_name.endswith(")"): + event_name = event_name[6:-1] + event_name = "".join(c if c.isprintable() else "?" for c in event_name) + pid = sample.sample_pid + sample_time = getattr(sample, "sample_time", 0) or 0 + + if sample_time > 0: + if self.last_print_time == 0: + self.last_print_time = sample_time + elif (sample_time > self.last_print_time and + sample_time - self.last_print_time >= self.interval_ns): + self.print_totals() + self.last_print_time = sample_time + + # Map each event onto the totals it updates. "enter" events count the + # requested bytes, "exit" events the transferred bytes or the error. + handlers = { + "syscalls:sys_enter_read": (self.reads, "total_reads", None), + "syscalls:sys_exit_read": (self.reads, None, "bytes_read"), + "syscalls:sys_enter_write": (self.writes, "total_writes", None), + "syscalls:sys_exit_write": (self.writes, None, "bytes_written"), + } + handler = handlers.get(event_name) + if not handler: + self.unhandled[event_name] += 1 + return + + totals, count_key, bytes_key = handler + try: + value = sample.count if count_key else sample.ret + except AttributeError: + self.unhandled[event_name] += 1 + return + + data = totals[pid] + data["comm"] = self.get_comm(pid, getattr(sample, "sample_tid", None)) + if count_key: + data["bytes_requested"] += value + data[count_key] += 1 + elif bytes_key: + # Convert unsigned 32-bit or 64-bit kernel error return values to signed integers. + # Because kernel read/write transfers are bounded by MAX_RW_COUNT (0x7ffff000 < 2 GiB), + # 0xfffff000..0xffffffff is always a 32-bit negative errno even on 64-bit hosts. + if value > 0: + if 0xfffff000 <= value <= 0xffffffff: + value -= 0x100000000 + elif value >= 0x8000000000000000: + value -= 0x10000000000000000 + if value >= 0: + data[bytes_key] += value + else: + data["errors"][value] += 1 + + def print_totals(self) -> None: + """Print summary tables.""" + if not self.offline: + print('\x1b[H\x1b[2J', end='') + print("read counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# reads':>10s} " + f"{'bytes_req':>10s} {'bytes_read':>10s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*10} {'-'*10}") + + count = 0 + 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']:10d} {data['bytes_read']:10d}" + ) + count += 1 + if count >= self.nlines: + break + + print("\nfailed reads by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'error #':>7s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*7} {'-'*10}") + + errcounts = [] + for pid, data in self.reads.items(): + for error, cnt in data["errors"].items(): + errcounts.append((pid, data["comm"], error, cnt)) + + sorted_errcounts = sorted(errcounts, key=lambda x: x[3], reverse=True) + for pid, comm, error, cnt in sorted_errcounts[:self.nlines]: + print(f"{pid:6d} {comm:<20s} {error:7d} {cnt:10d}") + + print("\nwrite counts by pid:\n") + print( + f"{'pid':>6s} {'comm':<20s} {'# writes':>10s} " + f"{'bytes_req':>10s} {'bytes_written':>13s}" + ) + print(f"{'-'*6} {'-'*20} {'-'*10} {'-'*10} {'-'*13}") + + count = 0 + for pid, data in sorted(self.writes.items(), + key=lambda kv: kv[1]["bytes_written"], reverse=True): + print( + f"{pid:6d} {data['comm']:<20s} {data['total_writes']:10d} " + f"{data['bytes_requested']:10d} {data['bytes_written']:13d}" + ) + count += 1 + if count >= self.nlines: + break + + print("\nfailed writes by pid:\n") + print(f"{'pid':>6s} {'comm':<20s} {'error #':>7s} {'# errors':>10s}") + print(f"{'-'*6} {'-'*20} {'-'*7} {'-'*10}") + + errcounts = [] + for pid, data in self.writes.items(): + for error, cnt in data["errors"].items(): + errcounts.append((pid, data["comm"], error, cnt)) + + sorted_errcounts = sorted(errcounts, key=lambda x: x[3], reverse=True) + for pid, comm, error, cnt in sorted_errcounts[:self.nlines]: + print(f"{pid:6d} {comm:<20s} {error:7d} {cnt:10d}") + + # Reset counts + self.reads.clear() + self.writes.clear() + self.comm_cache.clear() + + def run(self, input_file: str) -> None: + """Run the session.""" + self.session = perf.session(perf.data(input_file), sample=self.process_event) + try: + self.session.process_events() + finally: + # Break the reference cycle between perf.session and self.process_event + # because perf.session lacks cyclic GC support (tp_traverse). + self.session = None + + # Print final totals if there are any left + if self.reads or self.writes: + self.print_totals() + + 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 main() -> None: + """Main function.""" + parser = argparse.ArgumentParser(description="Trace r/w activity by PID") + parser.add_argument( + "interval", type=int, nargs="?", default=3, help="Refresh interval in seconds" + ) + parser.add_argument("-i", "--input", default="perf.data", help="Input file") + parser.add_argument("-l", "--live", action="store_true", help="Run in live mode") + args = parser.parse_args() + + analyzer = RwTop(args.interval) + try: + if args.live or (not os.path.exists(args.input) and args.input == "perf.data"): + # Live mode + events = ( + "syscalls:sys_enter_read,syscalls:sys_exit_read," + "syscalls:sys_enter_write,syscalls:sys_exit_write" + ) + live_session = LiveSession(events, sample_callback=analyzer.process_event) + print("Live mode started. Press Ctrl+C to stop.", file=sys.stderr) + live_session.run() + else: + analyzer.offline = True + analyzer.run(args.input) + except IOError as e: + print(e, file=sys.stderr) + sys.exit(1) + except KeyboardInterrupt: + if not analyzer.offline: + print("\nStopping live mode...", file=sys.stderr) + if analyzer.reads or analyzer.writes: + analyzer.print_totals() + +if __name__ == "__main__": + main() |