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linux/tools/perf/Documentation/perf-stat.txt
Andi Kleen 4cabc3d1cb tools/perf/stat: Add perf stat --transaction 
Add support to perf stat to print the basic transactional execution statistics:
Total cycles, Cycles in Transaction, Cycles in aborted transsactions
using the in_tx and in_tx_checkpoint qualifiers.
Transaction Starts and Elision Starts, to compute the average transaction
length.

This is a reasonable overview over the success of the transactions.

Also support architectures that have a transaction aborted cycles
counter like POWER8. Since that is awkward to handle in the kernel
abstract handle both cases here.

Enable with a new --transaction / -T option.

This requires measuring these events in a group, since they depend on each
other.

This is implemented by using TM sysfs events exported by the kernel

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnaldo Carvalho de Melo <acme@infradead.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1377128846-977-5-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-04 10:06:07 +02:00

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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). 0 means forever.
-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
--per-socket::
Aggregate counts per processor socket for system-wide mode measurements. This
is a useful mode to detect imbalance between sockets. To enable this mode,
use --per-socket in addition to -a. (system-wide). The output includes the
socket number and the number of online processors on that socket. This is
useful to gauge the amount of aggregation.
--per-core::
Aggregate counts per physical processor for system-wide mode measurements. This
is a useful mode to detect imbalance between physical cores. To enable this mode,
use --per-core in addition to -a. (system-wide). The output includes the
core number and the number of online logical processors on that physical processor.
-D msecs::
--initial-delay msecs::
After starting the program, wait msecs before measuring. This is useful to
filter out the startup phase of the program, which is often very different.
-T::
--transaction::
Print statistics of transactional execution if supported.
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]
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