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daf07d2207
'perf record' generates perf.data, which generates extra interrupts
for hard disk, amount of data to be collected increases with time.
Using eBPF trace can process the data in kernel, which solves the
preceding two problems.
Add -b/--use-bpf option for latency and report to support
tracing kwork events using eBPF:
1. Create bpf prog and attach to tracepoints,
2. Start tracing after command is entered,
3. After user hit "ctrl+c", stop tracing and report,
4. Support CPU and name filtering.
This commit implements the framework code and
does not add specific event support.
Test cases:
# perf kwork rep -h
Usage: perf kwork report [<options>]
-b, --use-bpf Use BPF to measure kwork runtime
-C, --cpu <cpu> list of cpus to profile
-i, --input <file> input file name
-n, --name <name> event name to profile
-s, --sort <key[,key2...]>
sort by key(s): runtime, max, count
-S, --with-summary Show summary with statistics
--time <str> Time span for analysis (start,stop)
# perf kwork lat -h
Usage: perf kwork latency [<options>]
-b, --use-bpf Use BPF to measure kwork latency
-C, --cpu <cpu> list of cpus to profile
-i, --input <file> input file name
-n, --name <name> event name to profile
-s, --sort <key[,key2...]>
sort by key(s): avg, max, count
--time <str> Time span for analysis (start,stop)
# perf kwork lat -b
Unsupported bpf trace class irq
# perf kwork rep -b
Unsupported bpf trace class irq
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-15-yangjihong1@huawei.com
[ Simplify work_findnew() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
181 lines
5.0 KiB
Plaintext
181 lines
5.0 KiB
Plaintext
perf-kowrk(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}
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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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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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By default it shows the individual work events such as irq, workqeueu,
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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, 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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SEE ALSO
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--------
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linkperf:perf-record[1]
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