xref: /linux-6.15/tools/workqueue/wq_monitor.py (revision 725e8ec5)
1#!/usr/bin/env drgn
2#
3# Copyright (C) 2023 Tejun Heo <[email protected]>
4# Copyright (C) 2023 Meta Platforms, Inc. and affiliates.
5
6desc = """
7This is a drgn script to monitor workqueues. For more info on drgn, visit
8https://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  CMwake   The number of concurrency-management wake-ups while executing a
15           work item of the workqueue.
16
17  mayday   The number of times the rescuer was requested while waiting for
18           new worker creation.
19
20  rescued  The number of work items executed by the rescuer.
21"""
22
23import sys
24import signal
25import os
26import re
27import time
28import json
29
30import drgn
31from drgn.helpers.linux.list import list_for_each_entry,list_empty
32from drgn.helpers.linux.cpumask import for_each_possible_cpu
33
34import argparse
35parser = argparse.ArgumentParser(description=desc,
36                                 formatter_class=argparse.RawTextHelpFormatter)
37parser.add_argument('workqueue', metavar='REGEX', nargs='*',
38                    help='Target workqueue name patterns (all if empty)')
39parser.add_argument('-i', '--interval', metavar='SECS', type=float, default=1,
40                    help='Monitoring interval (0 to print once and exit)')
41parser.add_argument('-j', '--json', action='store_true',
42                    help='Output in json')
43args = parser.parse_args()
44
45def err(s):
46    print(s, file=sys.stderr, flush=True)
47    sys.exit(1)
48
49workqueues              = prog['workqueues']
50
51WQ_UNBOUND              = prog['WQ_UNBOUND']
52WQ_MEM_RECLAIM          = prog['WQ_MEM_RECLAIM']
53
54PWQ_STAT_STARTED        = prog['PWQ_STAT_STARTED']      # work items started execution
55PWQ_STAT_COMPLETED      = prog['PWQ_STAT_COMPLETED']	# work items completed execution
56PWQ_STAT_CM_WAKEUP      = prog['PWQ_STAT_CM_WAKEUP']    # concurrency-management worker wakeups
57PWQ_STAT_MAYDAY         = prog['PWQ_STAT_MAYDAY']	# maydays to rescuer
58PWQ_STAT_RESCUED        = prog['PWQ_STAT_RESCUED']	# linked work items executed by rescuer
59PWQ_NR_STATS            = prog['PWQ_NR_STATS']
60
61class WqStats:
62    def __init__(self, wq):
63        self.name = wq.name.string_().decode()
64        self.unbound = wq.flags & WQ_UNBOUND != 0
65        self.mem_reclaim = wq.flags & WQ_MEM_RECLAIM != 0
66        self.stats = [0] * PWQ_NR_STATS
67        for pwq in list_for_each_entry('struct pool_workqueue', wq.pwqs.address_of_(), 'pwqs_node'):
68            for i in range(PWQ_NR_STATS):
69                self.stats[i] += int(pwq.stats[i])
70
71    def dict(self, now):
72        return { 'timestamp'            : now,
73                 'name'                 : self.name,
74                 'unbound'              : self.unbound,
75                 'mem_reclaim'          : self.mem_reclaim,
76                 'started'              : self.stats[PWQ_STAT_STARTED],
77                 'completed'            : self.stats[PWQ_STAT_COMPLETED],
78                 'cm_wakeup'            : self.stats[PWQ_STAT_CM_WAKEUP],
79                 'mayday'               : self.stats[PWQ_STAT_MAYDAY],
80                 'rescued'              : self.stats[PWQ_STAT_RESCUED], }
81
82    def table_header_str():
83        return f'{"":>24} {"total":>8} {"infl":>5} {"CMwake":>7} {"mayday":>7} {"rescued":>7}'
84
85    def table_row_str(self):
86        cm_wakeup = '-'
87        mayday = '-'
88        rescued = '-'
89
90        if not self.unbound:
91            cm_wakeup = str(self.stats[PWQ_STAT_CM_WAKEUP])
92
93        if self.mem_reclaim:
94            mayday = str(self.stats[PWQ_STAT_MAYDAY])
95            rescued = str(self.stats[PWQ_STAT_RESCUED])
96
97        out = f'{self.name[-24:]:24} ' \
98              f'{self.stats[PWQ_STAT_STARTED]:8} ' \
99              f'{max(self.stats[PWQ_STAT_STARTED] - self.stats[PWQ_STAT_COMPLETED], 0):5} ' \
100              f'{cm_wakeup:>7} ' \
101              f'{mayday:>7} ' \
102              f'{rescued:>7} '
103        return out.rstrip(':')
104
105exit_req = False
106
107def sigint_handler(signr, frame):
108    global exit_req
109    exit_req = True
110
111def main():
112    # handle args
113    table_fmt = not args.json
114    interval = args.interval
115
116    re_str = None
117    if args.workqueue:
118        for r in args.workqueue:
119            if re_str is None:
120                re_str = r
121            else:
122                re_str += '|' + r
123
124    filter_re = re.compile(re_str) if re_str else None
125
126    # monitoring loop
127    signal.signal(signal.SIGINT, sigint_handler)
128
129    while not exit_req:
130        now = time.time()
131
132        if table_fmt:
133            print()
134            print(WqStats.table_header_str())
135
136        for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_(), 'list'):
137            stats = WqStats(wq)
138            if filter_re and not filter_re.search(stats.name):
139                continue
140            if table_fmt:
141                print(stats.table_row_str())
142            else:
143                print(stats.dict(now))
144
145        if interval == 0:
146            break
147        time.sleep(interval)
148
149if __name__ == "__main__":
150    main()
151