1 perf-kwork(1) 1 perf-kwork(1)
2 ============= 2 =============
3 3
4 NAME 4 NAME
5 ---- 5 ----
6 perf-kwork - Tool to trace/measure kernel work 6 perf-kwork - Tool to trace/measure kernel work properties (latencies)
7 7
8 SYNOPSIS 8 SYNOPSIS
9 -------- 9 --------
10 [verse] 10 [verse]
11 'perf kwork' {record|report|latency|timehist|t 11 'perf kwork' {record|report|latency|timehist|top}
12 12
13 DESCRIPTION 13 DESCRIPTION
14 ----------- 14 -----------
15 There are several variants of 'perf kwork': 15 There are several variants of 'perf kwork':
16 16
17 'perf kwork record <command>' to record the 17 'perf kwork record <command>' to record the kernel work
18 of an arbitrary workload. 18 of an arbitrary workload.
19 19
20 'perf kwork report' to report the per kwork 20 'perf kwork report' to report the per kwork runtime.
21 21
22 'perf kwork latency' to report the per kwork 22 'perf kwork latency' to report the per kwork latencies.
23 23
24 'perf kwork timehist' provides an analysis o 24 'perf kwork timehist' provides an analysis of kernel work events.
25 25
26 'perf kwork top' to report the task cpu usag 26 'perf kwork top' to report the task cpu usage.
27 27
28 Example usage: 28 Example usage:
29 perf kwork record -- sleep 1 29 perf kwork record -- sleep 1
30 perf kwork report 30 perf kwork report
31 perf kwork report -b 31 perf kwork report -b
32 perf kwork latency 32 perf kwork latency
33 perf kwork latency -b 33 perf kwork latency -b
34 perf kwork timehist 34 perf kwork timehist
35 perf kwork top 35 perf kwork top
36 perf kwork top -b 36 perf kwork top -b
37 37
38 By default it shows the individual work eve 38 By default it shows the individual work events such as irq, workqueue,
39 including the run time and delay (time betw 39 including the run time and delay (time between raise and actually entry):
40 40
41 Runtime start Runtime end Cp 41 Runtime start Runtime end Cpu Kwork name Runtime Delaytime
42 42 (TYPE)NAME:NUM (msec) (msec)
43 ----------------- ----------------- ----- 43 ----------------- ----------------- ------ ------------------------- ---------- ----------
44 1811186.976062 1811186.976327 [0000 44 1811186.976062 1811186.976327 [0000] (s)RCU:9 0.266 0.114
45 1811186.978452 1811186.978547 [0000 45 1811186.978452 1811186.978547 [0000] (s)SCHED:7 0.095 0.171
46 1811186.980327 1811186.980490 [0000 46 1811186.980327 1811186.980490 [0000] (s)SCHED:7 0.162 0.083
47 1811186.981221 1811186.981271 [0000 47 1811186.981221 1811186.981271 [0000] (s)SCHED:7 0.050 0.077
48 1811186.984267 1811186.984318 [0000 48 1811186.984267 1811186.984318 [0000] (s)SCHED:7 0.051 0.075
49 1811186.987252 1811186.987315 [0000 49 1811186.987252 1811186.987315 [0000] (s)SCHED:7 0.063 0.081
50 1811186.987785 1811186.987843 [0006 50 1811186.987785 1811186.987843 [0006] (s)RCU:9 0.058 0.645
51 1811186.988319 1811186.988383 [0000 51 1811186.988319 1811186.988383 [0000] (s)SCHED:7 0.064 0.143
52 1811186.989404 1811186.989607 [0002 52 1811186.989404 1811186.989607 [0002] (s)TIMER:1 0.203 0.111
53 1811186.989660 1811186.989732 [0002 53 1811186.989660 1811186.989732 [0002] (s)SCHED:7 0.072 0.310
54 1811186.991295 1811186.991407 [0002 54 1811186.991295 1811186.991407 [0002] eth0:10 0.112
55 1811186.991639 1811186.991734 [0002 55 1811186.991639 1811186.991734 [0002] (s)NET_RX:3 0.095 0.277
56 1811186.989860 1811186.991826 [0002 56 1811186.989860 1811186.991826 [0002] (w)vmstat_shepherd 1.966 0.345
57 ... 57 ...
58 58
59 Times are in msec.usec. 59 Times are in msec.usec.
60 60
61 OPTIONS 61 OPTIONS
62 ------- 62 -------
63 -D:: 63 -D::
64 --dump-raw-trace=:: 64 --dump-raw-trace=::
65 Display verbose dump of the sched data 65 Display verbose dump of the sched data.
66 66
67 -f:: 67 -f::
68 --force:: 68 --force::
69 Don't complain, do it. 69 Don't complain, do it.
70 70
71 -k:: 71 -k::
72 --kwork:: 72 --kwork::
73 List of kwork to profile (irq, softirq 73 List of kwork to profile (irq, softirq, workqueue, sched, etc)
74 74
75 -v:: 75 -v::
76 --verbose:: 76 --verbose::
77 Be more verbose. (show symbol address, 77 Be more verbose. (show symbol address, etc)
78 78
79 OPTIONS for 'perf kwork report' 79 OPTIONS for 'perf kwork report'
80 ---------------------------- 80 ----------------------------
81 81
82 -b:: 82 -b::
83 --use-bpf:: 83 --use-bpf::
84 Use BPF to measure kwork runtime 84 Use BPF to measure kwork runtime
85 85
86 -C:: 86 -C::
87 --cpu:: 87 --cpu::
88 Only show events for the given CPU(s) 88 Only show events for the given CPU(s) (comma separated list).
89 89
90 -i:: 90 -i::
91 --input:: 91 --input::
92 Input file name. (default: perf.data u 92 Input file name. (default: perf.data unless stdin is a fifo)
93 93
94 -n:: 94 -n::
95 --name:: 95 --name::
96 Only show events for the given name. 96 Only show events for the given name.
97 97
98 -s:: 98 -s::
99 --sort:: 99 --sort::
100 Sort by key(s): runtime, max, count 100 Sort by key(s): runtime, max, count
101 101
102 -S:: 102 -S::
103 --with-summary:: 103 --with-summary::
104 Show summary with statistics 104 Show summary with statistics
105 105
106 --time:: 106 --time::
107 Only analyze samples within given time 107 Only analyze samples within given time window: <start>,<stop>. Times
108 have the format seconds.microseconds. 108 have the format seconds.microseconds. If start is not given (i.e., time
109 string is ',x.y') then analysis starts 109 string is ',x.y') then analysis starts at the beginning of the file. If
110 stop time is not given (i.e, time stri 110 stop time is not given (i.e, time string is 'x.y,') then analysis goes
111 to end of file. 111 to end of file.
112 112
113 OPTIONS for 'perf kwork latency' 113 OPTIONS for 'perf kwork latency'
114 ---------------------------- 114 ----------------------------
115 115
116 -b:: 116 -b::
117 --use-bpf:: 117 --use-bpf::
118 Use BPF to measure kwork latency 118 Use BPF to measure kwork latency
119 119
120 -C:: 120 -C::
121 --cpu:: 121 --cpu::
122 Only show events for the given CPU(s) 122 Only show events for the given CPU(s) (comma separated list).
123 123
124 -i:: 124 -i::
125 --input:: 125 --input::
126 Input file name. (default: perf.data u 126 Input file name. (default: perf.data unless stdin is a fifo)
127 127
128 -n:: 128 -n::
129 --name:: 129 --name::
130 Only show events for the given name. 130 Only show events for the given name.
131 131
132 -s:: 132 -s::
133 --sort:: 133 --sort::
134 Sort by key(s): avg, max, count 134 Sort by key(s): avg, max, count
135 135
136 --time:: 136 --time::
137 Only analyze samples within given time 137 Only analyze samples within given time window: <start>,<stop>. Times
138 have the format seconds.microseconds. 138 have the format seconds.microseconds. If start is not given (i.e., time
139 string is ',x.y') then analysis starts 139 string is ',x.y') then analysis starts at the beginning of the file. If
140 stop time is not given (i.e, time stri 140 stop time is not given (i.e, time string is 'x.y,') then analysis goes
141 to end of file. 141 to end of file.
142 142
143 OPTIONS for 'perf kwork timehist' 143 OPTIONS for 'perf kwork timehist'
144 --------------------------------- 144 ---------------------------------
145 145
146 -C:: 146 -C::
147 --cpu:: 147 --cpu::
148 Only show events for the given CPU(s) 148 Only show events for the given CPU(s) (comma separated list).
149 149
150 -g:: 150 -g::
151 --call-graph:: 151 --call-graph::
152 Display call chains if present (defaul 152 Display call chains if present (default off).
153 153
154 -i:: 154 -i::
155 --input:: 155 --input::
156 Input file name. (default: perf.data u 156 Input file name. (default: perf.data unless stdin is a fifo)
157 157
158 -k:: 158 -k::
159 --vmlinux=<file>:: 159 --vmlinux=<file>::
160 Vmlinux pathname 160 Vmlinux pathname
161 161
162 -n:: 162 -n::
163 --name:: 163 --name::
164 Only show events for the given name. 164 Only show events for the given name.
165 165
166 --kallsyms=<file>:: 166 --kallsyms=<file>::
167 Kallsyms pathname 167 Kallsyms pathname
168 168
169 --max-stack:: 169 --max-stack::
170 Maximum number of functions to display 170 Maximum number of functions to display in backtrace, default 5.
171 171
172 --symfs=<directory>:: 172 --symfs=<directory>::
173 Look for files with symbols relative to th 173 Look for files with symbols relative to this directory.
174 174
175 --time:: 175 --time::
176 Only analyze samples within given time 176 Only analyze samples within given time window: <start>,<stop>. Times
177 have the format seconds.microseconds. 177 have the format seconds.microseconds. If start is not given (i.e., time
178 string is ',x.y') then analysis starts 178 string is ',x.y') then analysis starts at the beginning of the file. If
179 stop time is not given (i.e, time stri 179 stop time is not given (i.e, time string is 'x.y,') then analysis goes
180 to end of file. 180 to end of file.
181 181
182 OPTIONS for 'perf kwork top' 182 OPTIONS for 'perf kwork top'
183 --------------------------------- 183 ---------------------------------
184 184
185 -b:: 185 -b::
186 --use-bpf:: 186 --use-bpf::
187 Use BPF to measure task cpu usage. 187 Use BPF to measure task cpu usage.
188 188
189 -C:: 189 -C::
190 --cpu:: 190 --cpu::
191 Only show events for the given CPU(s) 191 Only show events for the given CPU(s) (comma separated list).
192 192
193 -i:: 193 -i::
194 --input:: 194 --input::
195 Input file name. (default: perf.data u 195 Input file name. (default: perf.data unless stdin is a fifo)
196 196
197 -n:: 197 -n::
198 --name:: 198 --name::
199 Only show events for the given name. 199 Only show events for the given name.
200 200
201 -s:: 201 -s::
202 --sort:: 202 --sort::
203 Sort by key(s): rate, runtime, tid 203 Sort by key(s): rate, runtime, tid
204 204
205 --time:: 205 --time::
206 Only analyze samples within given time 206 Only analyze samples within given time window: <start>,<stop>. Times
207 have the format seconds.microseconds. 207 have the format seconds.microseconds. If start is not given (i.e., time
208 string is ',x.y') then analysis starts 208 string is ',x.y') then analysis starts at the beginning of the file. If
209 stop time is not given (i.e, time stri 209 stop time is not given (i.e, time string is 'x.y,') then analysis goes
210 to end of file. 210 to end of file.
211 211
212 SEE ALSO 212 SEE ALSO
213 -------- 213 --------
214 linkperf:perf-record[1] 214 linkperf:perf-record[1]
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