1 perf-sched(1) 1 perf-sched(1)
2 ============= !! 2 ==============
3 3
4 NAME 4 NAME
5 ---- 5 ----
6 perf-sched - Tool to trace/measure scheduler p 6 perf-sched - Tool to trace/measure scheduler properties (latencies)
7 7
8 SYNOPSIS 8 SYNOPSIS
9 -------- 9 --------
10 [verse] 10 [verse]
11 'perf sched' {record|latency|map|replay|script 11 'perf sched' {record|latency|map|replay|script|timehist}
12 12
13 DESCRIPTION 13 DESCRIPTION
14 ----------- 14 -----------
15 There are several variants of 'perf sched': 15 There are several variants of 'perf sched':
16 16
17 'perf sched record <command>' to record the 17 'perf sched record <command>' to record the scheduling events
18 of an arbitrary workload. 18 of an arbitrary workload.
19 19
20 'perf sched latency' to report the per task 20 'perf sched latency' to report the per task scheduling latencies
21 and other scheduling properties of the workl 21 and other scheduling properties of the workload.
22 22
23 Example usage: <<
24 perf sched record -- sleep 1 <<
25 perf sched latency <<
26 <<
27 -------------------------------------------- <<
28 Task | Runtime ms | Cou <<
29 -------------------------------------------- <<
30 perf:(2) | 2.804 ms | <<
31 NetworkManager:1343 | 0.372 ms | <<
32 kworker/1:2-xfs:4649 | 0.012 ms | <<
33 kworker/3:1-xfs:388 | 0.011 ms | <<
34 sleep:147736 | 0.938 ms | <<
35 <<
36 It shows Runtime(time that a task spent actu <<
37 Count(number of times a delay was calculated <<
38 task was ready to run but was kept waiting). <<
39 <<
40 Tasks with the same command name are merged <<
41 given within (), However if -p option is use <<
42 <<
43 'perf sched script' to see a detailed trace 23 'perf sched script' to see a detailed trace of the workload that
44 was recorded (aliased to 'perf script' for 24 was recorded (aliased to 'perf script' for now).
45 25
46 'perf sched replay' to simulate the workload 26 'perf sched replay' to simulate the workload that was recorded
47 via perf sched record. (this is done by star 27 via perf sched record. (this is done by starting up mockup threads
48 that mimic the workload based on the events 28 that mimic the workload based on the events in the trace. These
49 threads can then replay the timings (CPU run 29 threads can then replay the timings (CPU runtime and sleep patterns)
50 of the workload as it occurred when it was r 30 of the workload as it occurred when it was recorded - and can repeat
51 it a number of times, measuring its performa 31 it a number of times, measuring its performance.)
52 32
53 'perf sched map' to print a textual context- 33 'perf sched map' to print a textual context-switching outline of
54 workload captured via perf sched record. Co 34 workload captured via perf sched record. Columns stand for
55 individual CPUs, and the two-letter shortcut 35 individual CPUs, and the two-letter shortcuts stand for tasks that
56 are running on a CPU. A '*' denotes the CPU 36 are running on a CPU. A '*' denotes the CPU that had the event, and
57 a dot signals an idle CPU. 37 a dot signals an idle CPU.
58 38
59 'perf sched timehist' provides an analysis o 39 'perf sched timehist' provides an analysis of scheduling events.
60 40
61 Example usage: 41 Example usage:
62 perf sched record -- sleep 1 42 perf sched record -- sleep 1
63 perf sched timehist 43 perf sched timehist
64 44
65 By default it shows the individual schedule 45 By default it shows the individual schedule events, including the wait
66 time (time between sched-out and next sched 46 time (time between sched-out and next sched-in events for the task), the
67 task scheduling delay (time between runnabl !! 47 task scheduling delay (time between wakeup and actually running) and run
68 run time for the task: !! 48 time for the task:
69 49
70 time cpu task name 50 time cpu task name wait time sch delay run time
71 [tid/pid] 51 [tid/pid] (msec) (msec) (msec)
72 -------------- ------ ----------------- 52 -------------- ------ -------------------- --------- --------- ---------
73 79371.874569 [0011] gcc[31949] 53 79371.874569 [0011] gcc[31949] 0.014 0.000 1.148
74 79371.874591 [0010] gcc[31951] 54 79371.874591 [0010] gcc[31951] 0.000 0.000 0.024
75 79371.874603 [0010] migration/10[59] 55 79371.874603 [0010] migration/10[59] 3.350 0.004 0.011
76 79371.874604 [0011] <idle> 56 79371.874604 [0011] <idle> 1.148 0.000 0.035
77 79371.874723 [0005] <idle> 57 79371.874723 [0005] <idle> 0.016 0.000 1.383
78 79371.874746 [0005] gcc[31949] 58 79371.874746 [0005] gcc[31949] 0.153 0.078 0.022
79 ... 59 ...
80 60
81 Times are in msec.usec. 61 Times are in msec.usec.
82 62
83 OPTIONS 63 OPTIONS
84 ------- 64 -------
85 -i:: 65 -i::
86 --input=<file>:: 66 --input=<file>::
87 Input file name. (default: perf.data u 67 Input file name. (default: perf.data unless stdin is a fifo)
88 68
89 -v:: 69 -v::
90 --verbose:: 70 --verbose::
91 Be more verbose. (show symbol address, 71 Be more verbose. (show symbol address, etc)
92 72
93 -D:: 73 -D::
94 --dump-raw-trace=:: 74 --dump-raw-trace=::
95 Display verbose dump of the sched data 75 Display verbose dump of the sched data.
96 76
97 -f:: <<
98 --force:: <<
99 Don't complain, do it. <<
100 <<
101 OPTIONS for 'perf sched latency' <<
102 ------------------------------- <<
103 <<
104 -C:: <<
105 --CPU <n>:: <<
106 CPU to profile on. <<
107 <<
108 -p:: <<
109 --pids:: <<
110 latency stats per pid instead of per c <<
111 <<
112 -s:: <<
113 --sort <key[,key2...]>:: <<
114 sort by key(s): runtime, switch, avg, <<
115 by default it's sorted by "avg ,max ,s <<
116 <<
117 OPTIONS for 'perf sched map' 77 OPTIONS for 'perf sched map'
118 ---------------------------- 78 ----------------------------
119 79
120 --compact:: 80 --compact::
121 Show only CPUs with activity. Helps vi 81 Show only CPUs with activity. Helps visualizing on high core
122 count systems. 82 count systems.
123 83
124 --cpus:: 84 --cpus::
125 Show just entries with activities for 85 Show just entries with activities for the given CPUs.
126 86
127 --color-cpus:: 87 --color-cpus::
128 Highlight the given cpus. 88 Highlight the given cpus.
129 89
130 --color-pids:: 90 --color-pids::
131 Highlight the given pids. 91 Highlight the given pids.
132 92
133 --task-name <task>:: <<
134 Map output only for the given task nam <<
135 task names with a comma (without white <<
136 time is printed and is represented by <<
137 task name(s). <<
138 ('-' indicates other tasks while '.' i <<
139 <<
140 --fuzzy-name:: <<
141 Given task name(s) can be partially ma <<
142 <<
143 OPTIONS for 'perf sched timehist' 93 OPTIONS for 'perf sched timehist'
144 --------------------------------- 94 ---------------------------------
145 -k:: 95 -k::
146 --vmlinux=<file>:: 96 --vmlinux=<file>::
147 vmlinux pathname 97 vmlinux pathname
148 98
149 --kallsyms=<file>:: 99 --kallsyms=<file>::
150 kallsyms pathname 100 kallsyms pathname
151 101
152 -g:: 102 -g::
153 --call-graph:: !! 103 --no-call-graph::
154 Display call chains if present (defaul !! 104 Do not display call chains if present.
155 105
156 --max-stack:: 106 --max-stack::
157 Maximum number of functions to display 107 Maximum number of functions to display in backtrace, default 5.
158 108
159 -C=:: <<
160 --cpu=:: <<
161 Only show events for the given CPU(s) <<
162 <<
163 -p=:: <<
164 --pid=:: <<
165 Only show events for given process ID <<
166 <<
167 -t=:: <<
168 --tid=:: <<
169 Only show events for given thread ID ( <<
170 <<
171 -s:: 109 -s::
172 --summary:: 110 --summary::
173 Show only a summary of scheduling by threa 111 Show only a summary of scheduling by thread with min, max, and average
174 run times (in sec) and relative stddev. 112 run times (in sec) and relative stddev.
175 113
176 -S:: 114 -S::
177 --with-summary:: 115 --with-summary::
178 Show all scheduling events followed by a s 116 Show all scheduling events followed by a summary by thread with min,
179 max, and average run times (in sec) and re 117 max, and average run times (in sec) and relative stddev.
180 118
181 --symfs=<directory>:: 119 --symfs=<directory>::
182 Look for files with symbols relative to th 120 Look for files with symbols relative to this directory.
183 121
184 -V:: 122 -V::
185 --cpu-visual:: 123 --cpu-visual::
186 Show visual aid for sched switches by 124 Show visual aid for sched switches by CPU: 'i' marks idle time,
187 's' are scheduler events. 125 's' are scheduler events.
188 126
189 -w:: 127 -w::
190 --wakeups:: 128 --wakeups::
191 Show wakeup events. 129 Show wakeup events.
192 130
193 -M:: 131 -M::
194 --migrations:: 132 --migrations::
195 Show migration events. 133 Show migration events.
196 134
197 -n:: <<
198 --next:: <<
199 Show next task. <<
200 <<
201 -I:: 135 -I::
202 --idle-hist:: 136 --idle-hist::
203 Show idle-related events only. 137 Show idle-related events only.
204 138
205 --time:: 139 --time::
206 Only analyze samples within given time 140 Only analyze samples within given time window: <start>,<stop>. Times
207 have the format seconds.microseconds. 141 have the format seconds.microseconds. If start is not given (i.e., time
208 string is ',x.y') then analysis starts 142 string is ',x.y') then analysis starts at the beginning of the file. If
209 stop time is not given (i.e, time stri 143 stop time is not given (i.e, time string is 'x.y,') then analysis goes
210 to end of file. 144 to end of file.
211 145
212 --state:: <<
213 Show task state when it switched out. <<
214 <<
215 --show-prio:: <<
216 Show task priority. <<
217 <<
218 --prio:: <<
219 Only show events for given task priori <<
220 provided as a comma-separated list wit <<
221 priorities are specified with -: 120-1 <<
222 provided: 0,120-129. <<
223 <<
224 OPTIONS for 'perf sched replay' <<
225 ------------------------------ <<
226 <<
227 -r:: <<
228 --repeat <n>:: <<
229 repeat the workload n times (0: infini <<
230 146
231 SEE ALSO 147 SEE ALSO
232 -------- 148 --------
233 linkperf:perf-record[1] 149 linkperf:perf-record[1]
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