linux/tools/perf/Documentation/perf-bench.txt
Davidlohr Bueso 231457ec70 perf bench: Add epoll_ctl(2) benchmark
Benchmark the various operations allowed for epoll_ctl(2).  The idea is
to concurrently stress a single epoll instance doing add/mod/del
operations.

Committer testing:

  # perf bench epoll ctl
  # Running 'epoll/ctl' benchmark:
  Run summary [PID 20344]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.

  [thread  0] fdmap: 0x21a46b0 ... 0x21a47ac [ add: 1680960 ops; mod: 1680960 ops; del: 1680960 ops ]
  [thread  1] fdmap: 0x21a4960 ... 0x21a4a5c [ add: 1685440 ops; mod: 1685440 ops; del: 1685440 ops ]
  [thread  2] fdmap: 0x21a4c10 ... 0x21a4d0c [ add: 1674368 ops; mod: 1674368 ops; del: 1674368 ops ]
  [thread  3] fdmap: 0x21a4ec0 ... 0x21a4fbc [ add: 1677568 ops; mod: 1677568 ops; del: 1677568 ops ]

  Averaged 1679584 ADD operations (+- 0.14%)
  Averaged 1679584 MOD operations (+- 0.14%)
  Averaged 1679584 DEL operations (+- 0.14%)
  #

Lets measure those calls with 'perf trace' to get a glympse at what this
benchmark is doing in terms of syscalls:

  # perf trace -m32768 -s perf bench epoll ctl
  # Running 'epoll/ctl' benchmark:
  Run summary [PID 20405]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.

  [thread  0] fdmap: 0x21764e0 ... 0x21765dc [ add: 1100480 ops; mod: 1100480 ops; del: 1100480 ops ]
  [thread  1] fdmap: 0x2176790 ... 0x217688c [ add: 1250176 ops; mod: 1250176 ops; del: 1250176 ops ]
  [thread  2] fdmap: 0x2176a40 ... 0x2176b3c [ add: 1022464 ops; mod: 1022464 ops; del: 1022464 ops ]
  [thread  3] fdmap: 0x2176cf0 ... 0x2176dec [ add: 705472 ops; mod: 705472 ops; del: 705472 ops ]

  Averaged 1019648 ADD operations (+- 11.27%)
  Averaged 1019648 MOD operations (+- 11.27%)
  Averaged 1019648 DEL operations (+- 11.27%)

  Summary of events:

  epoll-ctl (20405), 1264 events, 0.0%

   syscall            calls    total       min       avg       max      stddev
                               (msec)    (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- --------- ---------     ------
   eventfd2             256     9.514     0.001     0.037     5.243     68.00%
   clone                  4     1.245     0.204     0.311     0.531     24.13%
   mprotect              66     0.345     0.002     0.005     0.021      7.43%
   openat                45     0.313     0.004     0.007     0.073     21.93%
   mmap                  88     0.302     0.002     0.003     0.013      5.02%
   futex                  4     0.160     0.002     0.040     0.140     83.43%
   sched_setaffinity      4     0.124     0.005     0.031     0.070     49.39%
   read                  44     0.103     0.001     0.002     0.013     15.54%
   fstat                 40     0.052     0.001     0.001     0.003      5.43%
   close                 39     0.039     0.001     0.001     0.001      1.48%
   stat                   9     0.034     0.003     0.004     0.006      7.30%
   access                 3     0.023     0.007     0.008     0.008      4.25%
   open                   2     0.021     0.008     0.011     0.013     22.60%
   getdents               4     0.019     0.001     0.005     0.009     37.15%
   write                  2     0.013     0.004     0.007     0.009     38.48%
   munmap                 1     0.010     0.010     0.010     0.010      0.00%
   brk                    3     0.006     0.001     0.002     0.003     26.34%
   rt_sigprocmask         2     0.004     0.001     0.002     0.003     43.95%
   rt_sigaction           3     0.004     0.001     0.001     0.002     16.07%
   prlimit64              3     0.004     0.001     0.001     0.001      5.39%
   prctl                  1     0.003     0.003     0.003     0.003      0.00%
   epoll_create           1     0.003     0.003     0.003     0.003      0.00%
   lseek                  2     0.002     0.001     0.001     0.001     11.42%
   sched_getaffinity        1     0.002     0.002     0.002     0.002      0.00%
   arch_prctl             1     0.002     0.002     0.002     0.002      0.00%
   set_tid_address        1     0.001     0.001     0.001     0.001      0.00%
   getpid                 1     0.001     0.001     0.001     0.001      0.00%
   set_robust_list        1     0.001     0.001     0.001     0.001      0.00%
   execve                 1     0.000     0.000     0.000     0.000      0.00%

 epoll-ctl (20406), 1245480 events, 14.6%

   syscall            calls    total       min       avg       max      stddev
                               (msec)    (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- --------- ---------     ------
   epoll_ctl         619511  1034.927     0.001     0.002     6.691      0.67%
   nanosleep           3226   616.114     0.006     0.191    10.376      7.57%
   futex                  2    11.336     0.002     5.668    11.334     99.97%
   set_robust_list        1     0.001     0.001     0.001     0.001      0.00%
   clone                  1     0.000     0.000     0.000     0.000      0.00%

 epoll-ctl (20407), 1243151 events, 14.5%

   syscall            calls    total       min       avg       max      stddev
                               (msec)    (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- --------- ---------     ------
   epoll_ctl         618350  1042.181     0.001     0.002     2.512      0.40%
   nanosleep           3220   366.261     0.012     0.114    18.162      9.59%
   futex                  4     5.463     0.001     1.366     5.427     99.12%
   set_robust_list        1     0.002     0.002     0.002     0.002      0.00%

 epoll-ctl (20408), 1801690 events, 21.1%

   syscall            calls    total       min       avg       max      stddev
                               (msec)    (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- --------- ---------     ------
   epoll_ctl         896174  1540.581     0.001     0.002     6.987      0.74%
   nanosleep           4667   783.393     0.006     0.168    10.419      7.10%
   futex                  2     4.682     0.002     2.341     4.681     99.93%
   set_robust_list        1     0.002     0.002     0.002     0.002      0.00%
   clone                  1     0.000     0.000     0.000     0.000      0.00%

 epoll-ctl (20409), 4254890 events, 49.8%

   syscall            calls    total       min       avg       max      stddev
                               (msec)    (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- --------- ---------     ------
   epoll_ctl        2116416  3768.097     0.001     0.002     9.956      0.41%
   nanosleep          11023  1141.778     0.006     0.104     9.447      4.95%
   futex                  3     0.037     0.002     0.012     0.029     70.50%
   set_robust_list        1     0.008     0.008     0.008     0.008      0.00%
   madvise                1     0.005     0.005     0.005     0.005      0.00%
   clone                  1     0.000     0.000     0.000     0.000      0.00%
  #

Committer notes:

Fix build on fedora:24-x-ARC-uClibc, debian:experimental-x-mips,
debian:experimental-x-mipsel, ubuntu:16.04-x-arm and ubuntu:16.04-x-powerpc

    CC       /tmp/build/perf/bench/epoll-ctl.o
  bench/epoll-ctl.c: In function 'init_fdmaps':
  bench/epoll-ctl.c:214:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
    for (i = 0; i < nfds; i+=inc) {
                  ^
  bench/epoll-ctl.c: In function 'bench_epoll_ctl':
  bench/epoll-ctl.c:377:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
    for (i = 0; i < nthreads; i++) {
                  ^
  bench/epoll-ctl.c:388:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
    for (i = 0; i < nthreads; i++) {
                  ^
  cc1: all warnings being treated as errors

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Link: http://lkml.kernel.org/r/20181106152226.20883-3-dave@stgolabs.net
[ Use inttypes.h to print rlim_t fields, fixing the build on Alpine Linux / musl libc ]
[ Check if eventfd() is available, i.e. if HAVE_EVENTFD is defined ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-11-21 22:39:55 -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.
'epoll'::
Eventpoll (epoll) 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::
--nr_loops=::
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::
--size::
Specify size of memory to copy (default: 1MB).
Available units are B, KB, MB, GB and TB (case insensitive).
-f::
--function::
Specify function to copy (default: default).
Available functions are depend on the architecture.
On x86-64, x86-64-unrolled, x86-64-movsq and x86-64-movsb are supported.
-l::
--nr_loops::
Repeat memcpy invocation this number of times.
-c::
--cycles::
Use perf's cpu-cycles event instead of gettimeofday syscall.
*memset*::
Suite for evaluating performance of simple memory set in various ways.
Options of *memset*
^^^^^^^^^^^^^^^^^^^
-l::
--size::
Specify size of memory to set (default: 1MB).
Available units are B, KB, MB, GB and TB (case insensitive).
-f::
--function::
Specify function to set (default: default).
Available functions are depend on the architecture.
On x86-64, x86-64-unrolled, x86-64-stosq and x86-64-stosb are supported.
-l::
--nr_loops::
Repeat memset invocation this number of times.
-c::
--cycles::
Use perf's cpu-cycles event instead of gettimeofday syscall.
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.
*lock-pi*::
Suite for evaluating futex lock_pi calls.
SUITES FOR 'epoll'
~~~~~~~~~~~~~~~~~~
*wait*::
Suite for evaluating concurrent epoll_wait calls.
*ctl*::
Suite for evaluating multiple epoll_ctl calls.
SEE ALSO
--------
linkperf:perf[1]