linux/tools/perf/Documentation/perf-record.txt
Frederic Weisbecker 1b290d670f perf tools: Add support for breakpoint events in perf tools
Add the breakpoint events support with this new sysnopsis:

  mem:addr[:access]

Where addr is a raw addr value in the kernel and access can be
either [r][w][x]

Example to profile tasklist_lock:

	$ grep tasklist_lock /proc/kallsyms
	ffffffff8189c000 D tasklist_lock

	$ perf record -e mem:0xffffffff8189c000:rw -a -f -c 1
	$ perf report

	# Samples: 62
	#
	# Overhead          Command  Shared Object  Symbol
	# ........  ...............  .............  ......
	#
	    29.03%          swapper  [kernel]       [k] _raw_read_trylock
	    29.03%          swapper  [kernel]       [k] _raw_read_unlock
	    19.35%             init  [kernel]       [k] _raw_read_trylock
	    19.35%             init  [kernel]       [k] _raw_read_unlock
	     1.61%         events/0  [kernel]       [k] _raw_read_trylock
	     1.61%         events/0  [kernel]       [k] _raw_read_unlock

Coming soon:

 - Support for symbols in the event definition.

 - Default period to 1 for breakpoint events because these are
   not high frequency events. The same thing is needed for trace
   events.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1258987355-8751-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
2009-11-23 18:18:31 +01:00

109 lines
2.1 KiB
Plaintext

perf-record(1)
==============
NAME
----
perf-record - Run a command and record its profile into perf.data
SYNOPSIS
--------
[verse]
'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] <command>
'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] -- <command> [<options>]
DESCRIPTION
-----------
This command runs a command and gathers a performance counter profile
from it, into perf.data - without displaying anything.
This file can then be inspected later on, using 'perf report'.
OPTIONS
-------
<command>...::
Any command you can specify in a shell.
-e::
--event=::
Select the PMU event. Selection can be:
- a symbolic event name (use 'perf list' to list all events)
- a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
hexadecimal event descriptor.
- a hardware breakpoint event in the form of '\mem:addr[:access]'
where addr is the address in memory you want to break in.
Access is the memory access type (read, write, execute) it can
be passed as follows: '\mem:addr[:[r][w][x]]'.
If you want to profile read-write accesses in 0x1000, just set
'mem:0x1000:rw'.
-a::
System-wide collection.
-l::
Scale counter values.
-p::
--pid=::
Record events on existing pid.
-r::
--realtime=::
Collect data with this RT SCHED_FIFO priority.
-A::
--append::
Append to the output file to do incremental profiling.
-f::
--force::
Overwrite existing data file.
-c::
--count=::
Event period to sample.
-o::
--output=::
Output file name.
-i::
--inherit::
Child tasks inherit counters.
-F::
--freq=::
Profile at this frequency.
-m::
--mmap-pages=::
Number of mmap data pages.
-g::
--call-graph::
Do call-graph (stack chain/backtrace) recording.
-v::
--verbose::
Be more verbose (show counter open errors, etc).
-s::
--stat::
Per thread counts.
-d::
--data::
Sample addresses.
-n::
--no-samples::
Don't sample.
-R::
--raw-samples::
Collect raw sample records from all opened counters (typically for tracepoint counters).
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1]