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Like trace subcommand, it should be able to pass some options to control
the tracing behavior for the function graph tracer.
But some options are limited in order to maintain the internal behavior.
For example, it can limit the function call depth like below:
# perf ftrace profile --graph-opts depth=5 -- myprog
Committer testing:
root@number:~# perf ftrace profile --graph-opts thresh=1000 -- sleep 1
# Total (us) Avg (us) Max (us) Count Function
1001419.301 500709.650 1000032.000 2 x64_sys_call
1000032.000 1000032.000 1000032.000 1 __x64_sys_clock_nanosleep
1000032.000 1000032.000 1000032.000 1 common_nsleep
1000031.000 1000031.000 1000031.000 1 do_nanosleep
1000031.000 1000031.000 1000031.000 1 hrtimer_nanosleep
1000024.000 1000024.000 1000024.000 1 schedule
1387.208 1387.208 1387.208 1 __x64_sys_execve
1386.691 1386.691 1386.691 1 do_execveat_common.isra.0
1334.170 1334.170 1334.170 1 bprm_execve
1258.413 1258.413 1258.413 1 load_elf_binary
1123.068 1123.068 1123.068 1 begin_new_exec
1113.550 1113.550 1113.550 1 mmput
1109.237 1109.237 1109.237 1 exit_mmap
root@number:~# perf ftrace profile --graph-opts thresh=1200 -- sleep 1
# Total (us) Avg (us) Max (us) Count Function
1001448.204 500724.102 1000018.000 2 x64_sys_call
1000017.000 1000017.000 1000017.000 1 __x64_sys_clock_nanosleep
1000017.000 1000017.000 1000017.000 1 common_nsleep
1000017.000 1000017.000 1000017.000 1 hrtimer_nanosleep
1000016.000 1000016.000 1000016.000 1 do_nanosleep
1000012.000 1000012.000 1000012.000 1 schedule
1430.112 1430.112 1430.112 1 __x64_sys_execve
1429.581 1429.581 1429.581 1 do_execveat_common.isra.0
1376.289 1376.289 1376.289 1 bprm_execve
1301.743 1301.743 1301.743 1 load_elf_binary
root@number:~#
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250107224352.1128669-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
216 lines
6.4 KiB
Plaintext
216 lines
6.4 KiB
Plaintext
perf-ftrace(1)
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==============
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NAME
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----
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perf-ftrace - simple wrapper for kernel's ftrace functionality
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SYNOPSIS
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--------
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[verse]
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'perf ftrace' {trace|latency|profile} <command>
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DESCRIPTION
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-----------
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The 'perf ftrace' command provides a collection of subcommands which use
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kernel's ftrace infrastructure.
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'perf ftrace trace' is a simple wrapper of the ftrace. It only supports
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single thread tracing currently and just reads trace_pipe in text and then
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write it to stdout.
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'perf ftrace latency' calculates execution latency of a given function
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(optionally with BPF) and display it as a histogram.
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'perf ftrace profile' show a execution profile for each function including
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total, average, max time and the number of calls.
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The following options apply to perf ftrace.
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COMMON OPTIONS
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--------------
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-p::
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--pid=::
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Trace on existing process id (comma separated list).
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--tid=::
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Trace on existing thread id (comma separated list).
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-a::
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--all-cpus::
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Force system-wide collection. Scripts run without a <command>
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normally use -a by default, while scripts run with a <command>
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normally don't - this option allows the latter to be run in
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system-wide mode.
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-C::
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--cpu=::
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Only trace for the list of CPUs provided. Multiple CPUs can
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be provided as a comma separated list with no space like: 0,1.
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Ranges of CPUs are specified with -: 0-2.
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Default is to trace on all online CPUs.
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-v::
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--verbose::
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Increase the verbosity level.
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OPTIONS for 'perf ftrace trace'
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-------------------------------
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-t::
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--tracer=::
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Tracer to use when neither -G nor -F option is not
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specified: function_graph or function.
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-F::
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--funcs::
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List available functions to trace. It accepts a pattern to
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only list interested functions.
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-D::
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--delay::
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Time (ms) to wait before starting tracing after program start.
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-m::
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--buffer-size::
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Set the size of per-cpu tracing buffer, <size> is expected to
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be a number with appended unit character - B/K/M/G.
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--inherit::
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Trace children processes spawned by our target.
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-T::
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--trace-funcs=::
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Select function tracer and set function filter on the given
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function (or a glob pattern). Multiple functions can be given
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by using this option more than once. The function argument also
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can be a glob pattern. It will be passed to 'set_ftrace_filter'
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in tracefs.
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-N::
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--notrace-funcs=::
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Select function tracer and do not trace functions given by the
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argument. Like -T option, this can be used more than once to
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specify multiple functions (or glob patterns). It will be
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passed to 'set_ftrace_notrace' in tracefs.
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--func-opts::
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List of options allowed to set:
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- call-graph - Display kernel stack trace for function tracer.
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- irq-info - Display irq context info for function tracer.
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-G::
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--graph-funcs=::
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Select function_graph tracer and set graph filter on the given
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function (or a glob pattern). This is useful to trace for
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functions executed from the given function. This can be used more
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than once to specify multiple functions. It will be passed to
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'set_graph_function' in tracefs.
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-g::
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--nograph-funcs=::
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Select function_graph tracer and set graph notrace filter on the
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given function (or a glob pattern). Like -G option, this is useful
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for the function_graph tracer only and disables tracing for function
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executed from the given function. This can be used more than once to
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specify multiple functions. It will be passed to 'set_graph_notrace'
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in tracefs.
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--graph-opts::
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List of options allowed to set:
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- nosleep-time - Measure on-CPU time only for function_graph tracer.
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- noirqs - Ignore functions that happen inside interrupt.
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- verbose - Show process names, PIDs, timestamps, etc.
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- thresh=<n> - Setup trace duration threshold in microseconds.
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- depth=<n> - Set max depth for function graph tracer to follow.
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- tail - Print function name at the end.
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OPTIONS for 'perf ftrace latency'
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---------------------------------
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-T::
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--trace-funcs=::
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Set the function name to get the histogram. Unlike perf ftrace trace,
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it only allows single function to calculate the histogram.
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-b::
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--use-bpf::
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Use BPF to measure function latency instead of using the ftrace (it
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uses function_graph tracer internally).
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-n::
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--use-nsec::
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Use nano-second instead of micro-second as a base unit of the histogram.
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--bucket-range=::
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Bucket range in ms or ns (according to -n/--use-nsec), default is log2() mode.
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--min-latency=::
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Minimum latency for the start of the first bucket, in ms or ns (according to
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-n/--use-nsec).
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--max-latency=::
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Maximum latency for the start of the last bucket, in ms or ns (according to
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-n/--use-nsec). The setting is ignored if the value results in more than
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22 buckets.
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OPTIONS for 'perf ftrace profile'
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---------------------------------
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-T::
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--trace-funcs=::
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Set function filter on the given function (or a glob pattern).
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Multiple functions can be given by using this option more than once.
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The function argument also can be a glob pattern. It will be passed
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to 'set_ftrace_filter' in tracefs.
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-N::
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--notrace-funcs=::
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Do not trace functions given by the argument. Like -T option, this
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can be used more than once to specify multiple functions (or glob
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patterns). It will be passed to 'set_ftrace_notrace' in tracefs.
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-G::
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--graph-funcs=::
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Set graph filter on the given function (or a glob pattern). This is
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useful to trace for functions executed from the given function. This
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can be used more than once to specify multiple functions. It will be
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passed to 'set_graph_function' in tracefs.
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-g::
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--nograph-funcs=::
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Set graph notrace filter on the given function (or a glob pattern).
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Like -G option, this is useful for the function_graph tracer only and
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disables tracing for function executed from the given function. This
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can be used more than once to specify multiple functions. It will be
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passed to 'set_graph_notrace' in tracefs.
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-m::
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--buffer-size::
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Set the size of per-cpu tracing buffer, <size> is expected to
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be a number with appended unit character - B/K/M/G.
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-s::
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--sort=::
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Sort the result by the given field. Available values are:
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total, avg, max, count, name. Default is 'total'.
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--graph-opts::
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List of options allowed to set:
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- nosleep-time - Measure on-CPU time only for function_graph tracer.
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- noirqs - Ignore functions that happen inside interrupt.
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- thresh=<n> - Setup trace duration threshold in microseconds.
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- depth=<n> - Set max depth for function graph tracer to follow.
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SEE ALSO
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--------
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linkperf:perf-record[1], linkperf:perf-trace[1]
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