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