169 lines · python
1#!/usr/bin/env drgn2#3# Copyright (C) 2023 Tejun Heo <tj@kernel.org>4# Copyright (C) 2023 Meta Platforms, Inc. and affiliates.5 6desc = """7This is a drgn script to monitor workqueues. For more info on drgn, visit8https://github.com/osandov/drgn.9 10 total Total number of work items executed by the workqueue.11 12 infl The number of currently in-flight work items.13 14 CPUtime Total CPU time consumed by the workqueue in seconds. This is15 sampled from scheduler ticks and only provides ballpark16 measurement. "nohz_full=" CPUs are excluded from measurement.17 18 CPUitsv The number of times a concurrency-managed work item hogged CPU19 longer than the threshold (workqueue.cpu_intensive_thresh_us)20 and got excluded from concurrency management to avoid stalling21 other work items.22 23 CMW/RPR For per-cpu workqueues, the number of concurrency-management24 wake-ups while executing a work item of the workqueue. For25 unbound workqueues, the number of times a worker was repatriated26 to its affinity scope after being migrated to an off-scope CPU by27 the scheduler.28 29 mayday The number of times the rescuer was requested while waiting for30 new worker creation.31 32 rescued The number of work items executed by the rescuer.33"""34 35import signal36import re37import time38import json39 40import drgn41from drgn.helpers.linux.list import list_for_each_entry42 43import argparse44parser = argparse.ArgumentParser(description=desc,45 formatter_class=argparse.RawTextHelpFormatter)46parser.add_argument('workqueue', metavar='REGEX', nargs='*',47 help='Target workqueue name patterns (all if empty)')48parser.add_argument('-i', '--interval', metavar='SECS', type=float, default=1,49 help='Monitoring interval (0 to print once and exit)')50parser.add_argument('-j', '--json', action='store_true',51 help='Output in json')52args = parser.parse_args()53 54workqueues = prog['workqueues']55 56WQ_UNBOUND = prog['WQ_UNBOUND']57WQ_MEM_RECLAIM = prog['WQ_MEM_RECLAIM']58 59PWQ_STAT_STARTED = prog['PWQ_STAT_STARTED'] # work items started execution60PWQ_STAT_COMPLETED = prog['PWQ_STAT_COMPLETED'] # work items completed execution61PWQ_STAT_CPU_TIME = prog['PWQ_STAT_CPU_TIME'] # total CPU time consumed62PWQ_STAT_CPU_INTENSIVE = prog['PWQ_STAT_CPU_INTENSIVE'] # wq_cpu_intensive_thresh_us violations63PWQ_STAT_CM_WAKEUP = prog['PWQ_STAT_CM_WAKEUP'] # concurrency-management worker wakeups64PWQ_STAT_REPATRIATED = prog['PWQ_STAT_REPATRIATED'] # unbound workers brought back into scope65PWQ_STAT_MAYDAY = prog['PWQ_STAT_MAYDAY'] # maydays to rescuer66PWQ_STAT_RESCUED = prog['PWQ_STAT_RESCUED'] # linked work items executed by rescuer67PWQ_NR_STATS = prog['PWQ_NR_STATS']68 69class WqStats:70 def __init__(self, wq):71 self.name = wq.name.string_().decode()72 self.unbound = wq.flags & WQ_UNBOUND != 073 self.mem_reclaim = wq.flags & WQ_MEM_RECLAIM != 074 self.stats = [0] * PWQ_NR_STATS75 for pwq in list_for_each_entry('struct pool_workqueue', wq.pwqs.address_of_(), 'pwqs_node'):76 for i in range(PWQ_NR_STATS):77 self.stats[i] += int(pwq.stats[i])78 79 def dict(self, now):80 return { 'timestamp' : now,81 'name' : self.name,82 'unbound' : self.unbound,83 'mem_reclaim' : self.mem_reclaim,84 'started' : self.stats[PWQ_STAT_STARTED],85 'completed' : self.stats[PWQ_STAT_COMPLETED],86 'cpu_time' : self.stats[PWQ_STAT_CPU_TIME],87 'cpu_intensive' : self.stats[PWQ_STAT_CPU_INTENSIVE],88 'cm_wakeup' : self.stats[PWQ_STAT_CM_WAKEUP],89 'repatriated' : self.stats[PWQ_STAT_REPATRIATED],90 'mayday' : self.stats[PWQ_STAT_MAYDAY],91 'rescued' : self.stats[PWQ_STAT_RESCUED], }92 93 def table_header_str():94 return f'{"":>24} {"total":>8} {"infl":>5} {"CPUtime":>8} '\95 f'{"CPUitsv":>7} {"CMW/RPR":>7} {"mayday":>7} {"rescued":>7}'96 97 def table_row_str(self):98 cpu_intensive = '-'99 cmw_rpr = '-'100 mayday = '-'101 rescued = '-'102 103 if self.unbound:104 cmw_rpr = str(self.stats[PWQ_STAT_REPATRIATED]);105 else:106 cpu_intensive = str(self.stats[PWQ_STAT_CPU_INTENSIVE])107 cmw_rpr = str(self.stats[PWQ_STAT_CM_WAKEUP])108 109 if self.mem_reclaim:110 mayday = str(self.stats[PWQ_STAT_MAYDAY])111 rescued = str(self.stats[PWQ_STAT_RESCUED])112 113 out = f'{self.name[-24:]:24} ' \114 f'{self.stats[PWQ_STAT_STARTED]:8} ' \115 f'{max(self.stats[PWQ_STAT_STARTED] - self.stats[PWQ_STAT_COMPLETED], 0):5} ' \116 f'{self.stats[PWQ_STAT_CPU_TIME] / 1000000:8.1f} ' \117 f'{cpu_intensive:>7} ' \118 f'{cmw_rpr:>7} ' \119 f'{mayday:>7} ' \120 f'{rescued:>7} '121 return out.rstrip(':')122 123exit_req = False124 125def sigint_handler(signr, frame):126 global exit_req127 exit_req = True128 129def main():130 # handle args131 table_fmt = not args.json132 interval = args.interval133 134 re_str = None135 if args.workqueue:136 for r in args.workqueue:137 if re_str is None:138 re_str = r139 else:140 re_str += '|' + r141 142 filter_re = re.compile(re_str) if re_str else None143 144 # monitoring loop145 signal.signal(signal.SIGINT, sigint_handler)146 147 while not exit_req:148 now = time.time()149 150 if table_fmt:151 print()152 print(WqStats.table_header_str())153 154 for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_(), 'list'):155 stats = WqStats(wq)156 if filter_re and not filter_re.search(stats.name):157 continue158 if table_fmt:159 print(stats.table_row_str())160 else:161 print(stats.dict(now))162 163 if interval == 0:164 break165 time.sleep(interval)166 167if __name__ == "__main__":168 main()169