linux/tools/perf/Documentation/perf-bench.txt
Davidlohr Bueso d65817b4e7 perf bench futex: Support parallel waker threads
The futex-wake benchmark only measures wakeups done within a single
process. While this has value in its own, it does not really generate
any hb->lock contention.

A new benchmark 'wake-parallel' is added, by extending the futex-wake
code such that we can measure parallel waker threads. The program output
shows the avg per-thread latency in order to complete its share of
wakeups:

Run summary [PID 13474]: blocking on 512 threads (at [private] futex 0xa88668), 8 threads waking up 64 at a time.

[Run 1]: Avg per-thread latency (waking 64/512 threads) in 0.6230 ms (+-15.31%)
[Run 2]: Avg per-thread latency (waking 64/512 threads) in 0.5175 ms (+-29.95%)
[Run 3]: Avg per-thread latency (waking 64/512 threads) in 0.7578 ms (+-18.03%)
[Run 4]: Avg per-thread latency (waking 64/512 threads) in 0.8944 ms (+-12.54%)
[Run 5]: Avg per-thread latency (waking 64/512 threads) in 1.1204 ms (+-23.85%)
Avg per-thread latency (waking 64/512 threads) in 0.7826 ms (+-9.91%)

Naturally, different combinations of numbers of blocking and waker
threads will exhibit different information.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1431110280-20231-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-08 16:23:50 -03:00

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perf-bench(1)
=============
NAME
----
perf-bench - General framework for benchmark suites
SYNOPSIS
--------
[verse]
'perf bench' [<common options>] <subsystem> <suite> [<options>]
DESCRIPTION
-----------
This 'perf bench' command is a general framework for benchmark suites.
COMMON OPTIONS
--------------
-r::
--repeat=::
Specify amount of times to repeat the run (default 10).
-f::
--format=::
Specify format style.
Current available format styles are:
'default'::
Default style. This is mainly for human reading.
---------------------
% perf bench sched pipe # with no style specified
(executing 1000000 pipe operations between two tasks)
Total time:5.855 sec
5.855061 usecs/op
170792 ops/sec
---------------------
'simple'::
This simple style is friendly for automated
processing by scripts.
---------------------
% perf bench --format=simple sched pipe # specified simple
5.988
---------------------
SUBSYSTEM
---------
'sched'::
Scheduler and IPC mechanisms.
'mem'::
Memory access performance.
'numa'::
NUMA scheduling and MM benchmarks.
'futex'::
Futex stressing benchmarks.
'all'::
All benchmark subsystems.
SUITES FOR 'sched'
~~~~~~~~~~~~~~~~~~
*messaging*::
Suite for evaluating performance of scheduler and IPC mechanisms.
Based on hackbench by Rusty Russell.
Options of *messaging*
^^^^^^^^^^^^^^^^^^^^^^
-p::
--pipe::
Use pipe() instead of socketpair()
-t::
--thread::
Be multi thread instead of multi process
-g::
--group=::
Specify number of groups
-l::
--loop=::
Specify number of loops
Example of *messaging*
^^^^^^^^^^^^^^^^^^^^^^
---------------------
% perf bench sched messaging # run with default
options (20 sender and receiver processes per group)
(10 groups == 400 processes run)
Total time:0.308 sec
% perf bench sched messaging -t -g 20 # be multi-thread, with 20 groups
(20 sender and receiver threads per group)
(20 groups == 800 threads run)
Total time:0.582 sec
---------------------
*pipe*::
Suite for pipe() system call.
Based on pipe-test-1m.c by Ingo Molnar.
Options of *pipe*
^^^^^^^^^^^^^^^^^
-l::
--loop=::
Specify number of loops.
Example of *pipe*
^^^^^^^^^^^^^^^^^
---------------------
% perf bench sched pipe
(executing 1000000 pipe operations between two tasks)
Total time:8.091 sec
8.091833 usecs/op
123581 ops/sec
% perf bench sched pipe -l 1000 # loop 1000
(executing 1000 pipe operations between two tasks)
Total time:0.016 sec
16.948000 usecs/op
59004 ops/sec
---------------------
SUITES FOR 'mem'
~~~~~~~~~~~~~~~~
*memcpy*::
Suite for evaluating performance of simple memory copy in various ways.
Options of *memcpy*
^^^^^^^^^^^^^^^^^^^
-l::
--length::
Specify length of memory to copy (default: 1MB).
Available units are B, KB, MB, GB and TB (case insensitive).
-r::
--routine::
Specify routine to copy (default: default).
Available routines are depend on the architecture.
On x86-64, x86-64-unrolled, x86-64-movsq and x86-64-movsb are supported.
-i::
--iterations::
Repeat memcpy invocation this number of times.
-c::
--cycle::
Use perf's cpu-cycles event instead of gettimeofday syscall.
-o::
--only-prefault::
Show only the result with page faults before memcpy.
-n::
--no-prefault::
Show only the result without page faults before memcpy.
*memset*::
Suite for evaluating performance of simple memory set in various ways.
Options of *memset*
^^^^^^^^^^^^^^^^^^^
-l::
--length::
Specify length of memory to set (default: 1MB).
Available units are B, KB, MB, GB and TB (case insensitive).
-r::
--routine::
Specify routine to set (default: default).
Available routines are depend on the architecture.
On x86-64, x86-64-unrolled, x86-64-stosq and x86-64-stosb are supported.
-i::
--iterations::
Repeat memset invocation this number of times.
-c::
--cycle::
Use perf's cpu-cycles event instead of gettimeofday syscall.
-o::
--only-prefault::
Show only the result with page faults before memset.
-n::
--no-prefault::
Show only the result without page faults before memset.
SUITES FOR 'numa'
~~~~~~~~~~~~~~~~~
*mem*::
Suite for evaluating NUMA workloads.
SUITES FOR 'futex'
~~~~~~~~~~~~~~~~~~
*hash*::
Suite for evaluating hash tables.
*wake*::
Suite for evaluating wake calls.
*wake-parallel*::
Suite for evaluating parallel wake calls.
*requeue*::
Suite for evaluating requeue calls.
SEE ALSO
--------
linkperf:perf[1]