a1ac1d3c08
There are situations where there is enough information in the perf.data to process the samples. Updating the buildid cache may add unecessary overhead in terms of disk space and time (copying large elf images). A persistent option to do this already exists via the perfconfig file, simply do: [buildid] dir = /dev/null This patch provides a way to suppress builid cache updates on a per-run basis. It addds a new option, -N, to perf record. Buildids are still generated in the perf.data file. Cc: David S. Miller <davem@davemloft.net> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4c19ef89.93ecd80a.40dc.fffff8e9@mx.google.com> Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
122 lines
2.6 KiB
Plaintext
122 lines
2.6 KiB
Plaintext
perf-record(1)
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==============
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NAME
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----
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perf-record - Run a command and record its profile into perf.data
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SYNOPSIS
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--------
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[verse]
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'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] <command>
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'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] -- <command> [<options>]
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DESCRIPTION
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-----------
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This command runs a command and gathers a performance counter profile
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from it, into perf.data - without displaying anything.
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This file can then be inspected later on, using 'perf report'.
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OPTIONS
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-------
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<command>...::
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Any command you can specify in a shell.
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-e::
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--event=::
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Select the PMU event. Selection can be:
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- a symbolic event name (use 'perf list' to list all events)
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- a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
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hexadecimal event descriptor.
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- a hardware breakpoint event in the form of '\mem:addr[:access]'
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where addr is the address in memory you want to break in.
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Access is the memory access type (read, write, execute) it can
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be passed as follows: '\mem:addr[:[r][w][x]]'.
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If you want to profile read-write accesses in 0x1000, just set
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'mem:0x1000:rw'.
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-a::
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System-wide collection.
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-l::
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Scale counter values.
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-p::
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--pid=::
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Record events on existing pid.
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-r::
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--realtime=::
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Collect data with this RT SCHED_FIFO priority.
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-A::
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--append::
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Append to the output file to do incremental profiling.
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-f::
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--force::
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Overwrite existing data file. (deprecated)
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-c::
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--count=::
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Event period to sample.
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-o::
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--output=::
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Output file name.
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-i::
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--no-inherit::
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Child tasks do not inherit counters.
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-F::
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--freq=::
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Profile at this frequency.
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-m::
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--mmap-pages=::
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Number of mmap data pages.
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-g::
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--call-graph::
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Do call-graph (stack chain/backtrace) recording.
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-v::
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--verbose::
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Be more verbose (show counter open errors, etc).
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-s::
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--stat::
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Per thread counts.
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-d::
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--data::
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Sample addresses.
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-n::
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--no-samples::
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Don't sample.
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-R::
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--raw-samples::
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Collect raw sample records from all opened counters (default for tracepoint counters).
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-C::
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--cpu::
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Collect samples only on the list of cpus provided. Multiple CPUs can be provided as a
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comma-sperated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
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In per-thread mode with inheritance mode on (default), samples are captured only when
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the thread executes on the designated CPUs. Default is to monitor all CPUs.
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-N::
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--no-buildid-cache::
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Do not update the builid cache. This saves some overhead in situations
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where the information in the perf.data file (which includes buildids)
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is sufficient.
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SEE ALSO
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--------
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linkperf:perf-stat[1], linkperf:perf-list[1]
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