linux/tools/perf/Documentation/perf-script.txt
Anton Blanchard 5d67be97f8 perf report/annotate/script: Add option to specify a CPU range
Add an option to perf report/annotate/script to specify which
CPUs to operate on. This enables us to take a single system wide
profile and analyse each CPU (or group of CPUs) in isolation.

This was useful when profiling a multiprocess workload where the
bottleneck was on one CPU but this was hidden in the overall
profile. Per process and per thread breakdowns didn't help
because multiple processes were running on each CPU and no
single process consumed an entire CPU.

The patch converts the list of CPUs returned by cpu_map__new
into a bitmap for fast lookup. I wanted to use -C to be
consistent with perf top/record/stat, but unfortunately perf
report already uses -C <comms>.

 v2: Incorporate suggestions from David Ahern:
	- Added -c to perf script
	- Check that SAMPLE_CPU is set when -c is used
	- Update documentation

 v3: Create perf_session__cpu_bitmap()

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/20110704215750.11647eb9@kryten
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-05 10:44:44 +02:00

194 lines
6.6 KiB
Text

perf-script(1)
=============
NAME
----
perf-script - Read perf.data (created by perf record) and display trace output
SYNOPSIS
--------
[verse]
'perf script' [<options>]
'perf script' [<options>] record <script> [<record-options>] <command>
'perf script' [<options>] report <script> [script-args]
'perf script' [<options>] <script> <required-script-args> [<record-options>] <command>
'perf script' [<options>] <top-script> [script-args]
DESCRIPTION
-----------
This command reads the input file and displays the trace recorded.
There are several variants of perf script:
'perf script' to see a detailed trace of the workload that was
recorded.
You can also run a set of pre-canned scripts that aggregate and
summarize the raw trace data in various ways (the list of scripts is
available via 'perf script -l'). The following variants allow you to
record and run those scripts:
'perf script record <script> <command>' to record the events required
for 'perf script report'. <script> is the name displayed in the
output of 'perf script --list' i.e. the actual script name minus any
language extension. If <command> is not specified, the events are
recorded using the -a (system-wide) 'perf record' option.
'perf script report <script> [args]' 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 script
record <script>' is used and should be present for this command to
succeed. [args] refers to the (mainly optional) args expected by
the script.
'perf script <script> <required-script-args> <command>' to both
record the events required for <script> and to run the <script>
using 'live-mode' i.e. without writing anything to disk. <script>
is the name displayed in the output of 'perf script --list' i.e. the
actual script name minus any language extension. If <command> is
not specified, the events are recorded using the -a (system-wide)
'perf record' option. If <script> has any required args, they
should be specified before <command>. This mode doesn't allow for
optional script args to be specified; if optional script args are
desired, they can be specified using separate 'perf script record'
and 'perf script report' commands, with the stdout of the record step
piped to the stdin of the report script, using the '-o -' and '-i -'
options of the corresponding commands.
'perf script <top-script>' to both record the events required for
<top-script> and to run the <top-script> using 'live-mode'
i.e. without writing anything to disk. <top-script> is the name
displayed in the output of 'perf script --list' i.e. the actual
script name minus any language extension; a <top-script> is defined
as any script name ending with the string 'top'.
[<record-options>] can be passed to the record steps of 'perf script
record' and 'live-mode' variants; this isn't possible however for
<top-script> 'live-mode' or 'perf script report' variants.
See the 'SEE ALSO' section for links to language-specific
information on how to write and run your own trace scripts.
OPTIONS
-------
<command>...::
Any command you can specify in a shell.
-D::
--dump-raw-script=::
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 ['lang']::
--script=::
Process trace data with the given script ([lang]:script[.ext]).
If the string 'lang' is specified in place of a script name, a
list of supported languages will be displayed instead.
-g::
--gen-script=::
Generate perf-script.[ext] starter script for given language,
using current perf.data.
-a::
Force system-wide collection. Scripts run without a <command>
normally use -a by default, while scripts run with a <command>
normally don't - this option allows the latter to be run in
system-wide mode.
-i::
--input=::
Input file name.
-d::
--debug-mode::
Do various checks like samples ordering and lost events.
-f::
--fields::
Comma separated list of fields to print. Options are:
comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr.
Field list can be prepended with the type, trace, sw or hw,
to indicate to which event type the field list applies.
e.g., -f sw:comm,tid,time,ip,sym and -f trace:time,cpu,trace
perf script -f <fields>
is equivalent to:
perf script -f trace:<fields> -f sw:<fields> -f hw:<fields>
i.e., the specified fields apply to all event types if the type string
is not given.
The arguments are processed in the order received. A later usage can
reset a prior request. e.g.:
-f trace: -f comm,tid,time,ip,sym
The first -f suppresses trace events (field list is ""), but then the
second invocation sets the fields to comm,tid,time,ip,sym. In this case a
warning is given to the user:
"Overriding previous field request for all events."
Alternativey, consider the order:
-f comm,tid,time,ip,sym -f trace:
The first -f sets the fields for all events and the second -f
suppresses trace events. The user is given a warning message about
the override, and the result of the above is that only S/W and H/W
events are displayed with the given fields.
For the 'wildcard' option if a user selected field is invalid for an
event type, a message is displayed to the user that the option is
ignored for that type. For example:
$ perf script -f comm,tid,trace
'trace' not valid for hardware events. Ignoring.
'trace' not valid for software events. Ignoring.
Alternatively, if the type is given an invalid field is specified it
is an error. For example:
perf script -v -f sw:comm,tid,trace
'trace' not valid for software events.
At this point usage is displayed, and perf-script exits.
Finally, a user may not set fields to none for all event types.
i.e., -f "" is not allowed.
-k::
--vmlinux=<file>::
vmlinux pathname
--kallsyms=<file>::
kallsyms pathname
--symfs=<directory>::
Look for files with symbols relative to this directory.
-G::
--hide-call-graph::
When printing symbols do not display call chain.
-c::
--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
be provided as a comma-separated list with no space: 0,1. Ranges of
CPUs are specified with -: 0-2. Default is to report samples on all
CPUs.
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-script-perl[1],
linkperf:perf-script-python[1]