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diff --git a/tools/perf/Documentation/perf-kwork.txt b/tools/perf/Documentation/perf-kwork.txt new file mode 100644 index 000000000..482d6c52e --- /dev/null +++ b/tools/perf/Documentation/perf-kwork.txt @@ -0,0 +1,180 @@ +perf-kowrk(1) +============= + +NAME +---- +perf-kwork - Tool to trace/measure kernel work properties (latencies) + +SYNOPSIS +-------- +[verse] +'perf kwork' {record|report|latency|timehist} + +DESCRIPTION +----------- +There are several variants of 'perf kwork': + + 'perf kwork record <command>' to record the kernel work + of an arbitrary workload. + + 'perf kwork report' to report the per kwork runtime. + + 'perf kwork latency' to report the per kwork latencies. + + 'perf kwork timehist' provides an analysis of kernel work events. + + Example usage: + perf kwork record -- sleep 1 + perf kwork report + perf kwork report -b + perf kwork latency + perf kwork latency -b + perf kwork timehist + + By default it shows the individual work events such as irq, workqeueu, + including the run time and delay (time between raise and actually entry): + + Runtime start Runtime end Cpu Kwork name Runtime Delaytime + (TYPE)NAME:NUM (msec) (msec) + ----------------- ----------------- ------ ------------------------- ---------- ---------- + 1811186.976062 1811186.976327 [0000] (s)RCU:9 0.266 0.114 + 1811186.978452 1811186.978547 [0000] (s)SCHED:7 0.095 0.171 + 1811186.980327 1811186.980490 [0000] (s)SCHED:7 0.162 0.083 + 1811186.981221 1811186.981271 [0000] (s)SCHED:7 0.050 0.077 + 1811186.984267 1811186.984318 [0000] (s)SCHED:7 0.051 0.075 + 1811186.987252 1811186.987315 [0000] (s)SCHED:7 0.063 0.081 + 1811186.987785 1811186.987843 [0006] (s)RCU:9 0.058 0.645 + 1811186.988319 1811186.988383 [0000] (s)SCHED:7 0.064 0.143 + 1811186.989404 1811186.989607 [0002] (s)TIMER:1 0.203 0.111 + 1811186.989660 1811186.989732 [0002] (s)SCHED:7 0.072 0.310 + 1811186.991295 1811186.991407 [0002] eth0:10 0.112 + 1811186.991639 1811186.991734 [0002] (s)NET_RX:3 0.095 0.277 + 1811186.989860 1811186.991826 [0002] (w)vmstat_shepherd 1.966 0.345 + ... + + Times are in msec.usec. + +OPTIONS +------- +-D:: +--dump-raw-trace=:: + Display verbose dump of the sched data. + +-f:: +--force:: + Don't complain, do it. + +-k:: +--kwork:: + List of kwork to profile (irq, softirq, workqueue, etc) + +-v:: +--verbose:: + Be more verbose. (show symbol address, etc) + +OPTIONS for 'perf kwork report' +---------------------------- + +-b:: +--use-bpf:: + Use BPF to measure kwork runtime + +-C:: +--cpu:: + Only show events for the given CPU(s) (comma separated list). + +-i:: +--input:: + Input file name. (default: perf.data unless stdin is a fifo) + +-n:: +--name:: + Only show events for the given name. + +-s:: +--sort:: + Sort by key(s): runtime, max, count + +-S:: +--with-summary:: + Show summary with statistics + +--time:: + Only analyze samples within given time window: <start>,<stop>. Times + have the format seconds.microseconds. If start is not given (i.e., time + string is ',x.y') then analysis starts at the beginning of the file. If + stop time is not given (i.e, time string is 'x.y,') then analysis goes + to end of file. + +OPTIONS for 'perf kwork latency' +---------------------------- + +-b:: +--use-bpf:: + Use BPF to measure kwork latency + +-C:: +--cpu:: + Only show events for the given CPU(s) (comma separated list). + +-i:: +--input:: + Input file name. (default: perf.data unless stdin is a fifo) + +-n:: +--name:: + Only show events for the given name. + +-s:: +--sort:: + Sort by key(s): avg, max, count + +--time:: + Only analyze samples within given time window: <start>,<stop>. Times + have the format seconds.microseconds. If start is not given (i.e., time + string is ',x.y') then analysis starts at the beginning of the file. If + stop time is not given (i.e, time string is 'x.y,') then analysis goes + to end of file. + +OPTIONS for 'perf kwork timehist' +--------------------------------- + +-C:: +--cpu:: + Only show events for the given CPU(s) (comma separated list). + +-g:: +--call-graph:: + Display call chains if present (default off). + +-i:: +--input:: + Input file name. (default: perf.data unless stdin is a fifo) + +-k:: +--vmlinux=<file>:: + Vmlinux pathname + +-n:: +--name:: + Only show events for the given name. + +--kallsyms=<file>:: + Kallsyms pathname + +--max-stack:: + Maximum number of functions to display in backtrace, default 5. + +--symfs=<directory>:: + Look for files with symbols relative to this directory. + +--time:: + Only analyze samples within given time window: <start>,<stop>. Times + have the format seconds.microseconds. If start is not given (i.e., time + string is ',x.y') then analysis starts at the beginning of the file. If + stop time is not given (i.e, time string is 'x.y,') then analysis goes + to end of file. + +SEE ALSO +-------- +linkperf:perf-record[1] |