linux/tools/perf/Documentation/perf-stat.txt
Stephane Eranian 13370a9b5b perf stat: Add interval printing
This patch adds a new printing mode for perf stat.  It allows interval
printing. That means perf stat can now print event deltas at regular
time interval.  This is useful to detect phases in programs.

The -I option enables interval printing. It expects an interval duration
in milliseconds. Minimum is 100ms. Once, activated perf stat prints
events deltas since last printout. All modes are supported.

$ perf stat -I 1000 -e cycles noploop 10
noploop for 10 seconds
 #           time             counts events
      1.000109853      2,388,560,546 cycles
      2.000262846      2,393,332,358 cycles
      3.000354131      2,393,176,537 cycles
      4.000439503      2,393,203,790 cycles
      5.000527075      2,393,167,675 cycles
      6.000609052      2,393,203,670 cycles
      7.000691082      2,393,175,678 cycles

The output format makes it easy to feed into a plotting program such as
gnuplot when the -I option is used in combination with the -x option:

$ perf stat -x, -I 1000 -e cycles noploop 10
noploop for 10 seconds
1.000084113,2378775498,cycles
2.000245798,2391056897,cycles
3.000354445,2392089414,cycles
4.000459115,2390936603,cycles
5.000565341,2392108173,cycles

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1359460064-3060-3-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-30 10:36:53 -03:00

143 lines
3.9 KiB
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perf-stat(1)
============
NAME
----
perf-stat - Run a command and gather performance counter statistics
SYNOPSIS
--------
[verse]
'perf stat' [-e <EVENT> | --event=EVENT] [-a] <command>
'perf stat' [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]
DESCRIPTION
-----------
This command runs a command and gathers performance counter statistics
from it.
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) or a raw PMU
event (eventsel+umask) in the form of rNNN where NNN is a
hexadecimal event descriptor.
-i::
--no-inherit::
child tasks do not inherit counters
-p::
--pid=<pid>::
stat events on existing process id (comma separated list)
-t::
--tid=<tid>::
stat events on existing thread id (comma separated list)
-a::
--all-cpus::
system-wide collection from all CPUs
-c::
--scale::
scale/normalize counter values
-r::
--repeat=<n>::
repeat command and print average + stddev (max: 100)
-B::
--big-num::
print large numbers with thousands' separators according to locale
-C::
--cpu=::
Count only on 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.
In per-thread mode, this option is ignored. The -a option is still necessary
to activate system-wide monitoring. Default is to count on all CPUs.
-A::
--no-aggr::
Do not aggregate counts across all monitored CPUs in system-wide mode (-a).
This option is only valid in system-wide mode.
-n::
--null::
null run - don't start any counters
-v::
--verbose::
be more verbose (show counter open errors, etc)
-x SEP::
--field-separator SEP::
print counts using a CSV-style output to make it easy to import directly into
spreadsheets. Columns are separated by the string specified in SEP.
-G name::
--cgroup name::
monitor only in the container (cgroup) called "name". This option is available only
in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
to first event, second cgroup to second event and so on. It is possible to provide
an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
corresponding events, i.e., they always refer to events defined earlier on the command
line.
-o file::
--output file::
Print the output into the designated file.
--append::
Append to the output file designated with the -o option. Ignored if -o is not specified.
--log-fd::
Log output to fd, instead of stderr. Complementary to --output, and mutually exclusive
with it. --append may be used here. Examples:
3>results perf stat --log-fd 3 -- $cmd
3>>results perf stat --log-fd 3 --append -- $cmd
--pre::
--post::
Pre and post measurement hooks, e.g.:
perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
-I msecs::
--interval-print msecs::
print count deltas every N milliseconds (minimum: 100ms)
example: perf stat -I 1000 -e cycles -a sleep 5
EXAMPLES
--------
$ perf stat -- make -j
Performance counter stats for 'make -j':
8117.370256 task clock ticks # 11.281 CPU utilization factor
678 context switches # 0.000 M/sec
133 CPU migrations # 0.000 M/sec
235724 pagefaults # 0.029 M/sec
24821162526 CPU cycles # 3057.784 M/sec
18687303457 instructions # 2302.138 M/sec
172158895 cache references # 21.209 M/sec
27075259 cache misses # 3.335 M/sec
Wall-clock time elapsed: 719.554352 msecs
SEE ALSO
--------
linkperf:perf-top[1], linkperf:perf-list[1]