perf tools: Don't use parent comm if not set at fork time

[linux-2.6-block.git] / tools / perf / Documentation / perf-trace.txt

perf-trace(1)
==============

NAME
----
perf-trace - Read perf.data (created by perf record) and display trace output

SYNOPSIS
--------
[verse]
'perf trace' {record <script> | report <script> [args] }

DESCRIPTION
-----------
This command reads the input file and displays the trace recorded.

There are several variants of perf trace:

  'perf trace' to see a detailed trace of the workload that was
  recorded.

  'perf trace record <script>' to record the events required for 'perf
  trace report'.  <script> is the name displayed in the output of
  'perf trace --list' i.e. the actual script name minus any language
  extension.

  'perf trace report <script>' to run and display the results of
  <script>.  <script> is the name displayed in the output of 'perf
  trace --list' i.e. the actual script name minus any language
  extension.  The perf.data output from a previous run of 'perf trace
  record <script>' is used and should be present for this command to
  succeed.

OPTIONS
-------
-D::
--dump-raw-trace=::
        Display verbose dump of the trace data.

-L::
--Latency=::
        Show latency attributes (irqs/preemption disabled, etc).

-l::
--list=::
        Display a list of available trace scripts.

-s::
--script=::
        Process trace data with the given script ([lang]:script[.ext]).

-g::
--gen-script=::
        Generate perf-trace.[ext] starter script for given language,
        using current perf.data.

SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-trace-perl[1]