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