linux/tools/perf/Documentation/perf-record.txt
Stephane Eranian 2e6cdf996b perf tools: change event inheritance logic in stat and record
By default, event inheritance across fork and pthread_create was on but the -i
option of stat and record, which enabled inheritance, led to believe it was off
by default.

This patch fixes this logic by inverting the meaning of the -i option.  By
default inheritance is on whether you attach to a process (-p), a thread (-t)
or start a process. If you pass -i, then you turn off inheritance. Turning off
inheritance if you don't need it, helps limit perf resource usage as well.

The patch also fixes perf stat -t xxxx and perf record -t xxxx which did not
start the counters.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
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: <4bea9d2f.d60ce30a.0b5b.08e1@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-05-13 16:39:12 -03:00

109 lines
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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. (deprecated)
-c::
--count=::
Event period to sample.
-o::
--output=::
Output file name.
-i::
--no-inherit::
Child tasks do not 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 (default for tracepoint counters).
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1]