linux-stable/tools/perf/Documentation/perf-bench.txt

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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.
perf bench: Add epoll parallel epoll_wait benchmark This program benchmarks concurrent epoll_wait(2) for file descriptors that are monitored with with EPOLLIN along various semantics, by a single epoll instance. Such conditions can be found when using single/combined or multiple queuing when load balancing. Each thread has a number of private, nonblocking file descriptors, referred to as fdmap. A writer thread will constantly be writing to the fdmaps of all threads, minimizing each threads's chances of epoll_wait not finding any ready read events and blocking as this is not what we want to stress. Full details in the start of the C file. Committer testing: # perf bench Usage: perf bench [<common options>] <collection> <benchmark> [<options>] # List of all available benchmark collections: sched: Scheduler and IPC benchmarks mem: Memory access benchmarks numa: NUMA scheduling and MM benchmarks futex: Futex stressing benchmarks epoll: Epoll stressing benchmarks all: All benchmarks # perf bench epoll # List of available benchmarks for collection 'epoll': wait: Benchmark epoll concurrent epoll_waits all: Run all futex benchmarks # perf bench epoll wait # Running 'epoll/wait' benchmark: Run summary [PID 19295]: 3 threads monitoring on 64 file-descriptors for 8 secs. [thread 0] fdmap: 0xdaa650 ... 0xdaa74c [ 328241 ops/sec ] [thread 1] fdmap: 0xdaa900 ... 0xdaa9fc [ 351695 ops/sec ] [thread 2] fdmap: 0xdaabb0 ... 0xdaacac [ 381423 ops/sec ] Averaged 353786 operations/sec (+- 4.35%), total secs = 8 # Committer notes: Fix the build on debian:experimental-x-mips, debian:experimental-x-mipsel and others: CC /tmp/build/perf/bench/epoll-wait.o bench/epoll-wait.c: In function 'writerfn': bench/epoll-wait.c:399:12: error: format '%ld' expects argument of type 'long int', but argument 2 has type 'size_t' {aka 'unsigned int'} [-Werror=format=] printinfo("exiting writer-thread (total full-loops: %ld)\n", iter); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~ bench/epoll-wait.c:86:31: note: in definition of macro 'printinfo' do { if (__verbose) { printf(fmt, ## arg); fflush(stdout); } } while (0) ^~~ 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> <jbaron@akamai.com> Link: http://lkml.kernel.org/r/20181106152226.20883-2-dave@stgolabs.net Link: http://lkml.kernel.org/r/20181106182349.thdkpvshkna5vd7o@linux-r8p5> [ Applied above fixup as per Davidlohr's request ] [ 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>
2018-11-06 15:22:25 +00:00
'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.
perf bench: Add epoll parallel epoll_wait benchmark This program benchmarks concurrent epoll_wait(2) for file descriptors that are monitored with with EPOLLIN along various semantics, by a single epoll instance. Such conditions can be found when using single/combined or multiple queuing when load balancing. Each thread has a number of private, nonblocking file descriptors, referred to as fdmap. A writer thread will constantly be writing to the fdmaps of all threads, minimizing each threads's chances of epoll_wait not finding any ready read events and blocking as this is not what we want to stress. Full details in the start of the C file. Committer testing: # perf bench Usage: perf bench [<common options>] <collection> <benchmark> [<options>] # List of all available benchmark collections: sched: Scheduler and IPC benchmarks mem: Memory access benchmarks numa: NUMA scheduling and MM benchmarks futex: Futex stressing benchmarks epoll: Epoll stressing benchmarks all: All benchmarks # perf bench epoll # List of available benchmarks for collection 'epoll': wait: Benchmark epoll concurrent epoll_waits all: Run all futex benchmarks # perf bench epoll wait # Running 'epoll/wait' benchmark: Run summary [PID 19295]: 3 threads monitoring on 64 file-descriptors for 8 secs. [thread 0] fdmap: 0xdaa650 ... 0xdaa74c [ 328241 ops/sec ] [thread 1] fdmap: 0xdaa900 ... 0xdaa9fc [ 351695 ops/sec ] [thread 2] fdmap: 0xdaabb0 ... 0xdaacac [ 381423 ops/sec ] Averaged 353786 operations/sec (+- 4.35%), total secs = 8 # Committer notes: Fix the build on debian:experimental-x-mips, debian:experimental-x-mipsel and others: CC /tmp/build/perf/bench/epoll-wait.o bench/epoll-wait.c: In function 'writerfn': bench/epoll-wait.c:399:12: error: format '%ld' expects argument of type 'long int', but argument 2 has type 'size_t' {aka 'unsigned int'} [-Werror=format=] printinfo("exiting writer-thread (total full-loops: %ld)\n", iter); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~ bench/epoll-wait.c:86:31: note: in definition of macro 'printinfo' do { if (__verbose) { printf(fmt, ## arg); fflush(stdout); } } while (0) ^~~ 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> <jbaron@akamai.com> Link: http://lkml.kernel.org/r/20181106152226.20883-2-dave@stgolabs.net Link: http://lkml.kernel.org/r/20181106182349.thdkpvshkna5vd7o@linux-r8p5> [ Applied above fixup as per Davidlohr's request ] [ 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>
2018-11-06 15:22:25 +00:00
SUITES FOR 'epoll'
~~~~~~~~~~~~~~~~~~
*wait*::
Suite for evaluating concurrent epoll_wait calls.
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>
2018-11-06 15:22:26 +00:00
*ctl*::
Suite for evaluating multiple epoll_ctl calls.
SEE ALSO
--------
linkperf:perf[1]