perf bench sched pipe: Add -G/--cgroups option

The -G/--cgroups option is to put sender and receiver in different
cgroups in order to measure cgroup context switch overheads.

Users need to make sure the cgroups exist and accessible. The following
example should the effect of this change. Please don't forget taskset
before the perf bench to measure cgroup switches properly. Otherwise
each task would run on a different CPU and generate cgroup switches
regardless of this change.

# perf stat -e context-switches,cgroup-switches \
> taskset -c 0 perf bench sched pipe -l 10000 > /dev/null

Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000':

20,001 context-switches
2 cgroup-switches

0.053449651 seconds time elapsed

0.011286000 seconds user
0.041869000 seconds sys

# perf stat -e context-switches,cgroup-switches \
> taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB > /dev/null

Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB':

20,001 context-switches
20,001 cgroup-switches

0.052768627 seconds time elapsed

0.006284000 seconds user
0.046266000 seconds sys

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20231017202342.1353124-1-namhyung@kernel.org

perf bench uprobe: Add benchmark to test uprobe overhead

This just adds the initial "workload", a call to libc's usleep(1000us)
function:

$ perf stat --null perf bench uprobe all
# Running uprobe/baseline benchmark...
# Executed 1000 usleep(1000) calls
Total time: 1053533 usecs

1053.533 usecs/op

Performance counter stats for 'perf bench uprobe all':

1.061042896 seconds time elapsed

0.001079000 seconds user
0.006499000 seconds sys

$

More entries will be added using a BPF skel to add various uprobes to
the usleep() function.

Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andre Fredette <anfredet@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Dave Tucker <datucker@redhat.com>
Cc: Derek Barbosa <debarbos@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20230719204910.539044-2-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf: Various spelling fixes

Fix various spelling errors as reported by Debian's lintian tool.

"amount of times" -> "number of times"
ocurrence -> occurrence
upto -> up to

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230122122034.48020-1-didi.debian@cknow.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Add basic syscall benchmark

The usefulness of having a standard way of testing syscall performance
has come up from time to time[0]. Furthermore, some of our testing
machinery (such as 'mmtests') already makes use of a simplified version
of the microbenchmark. This patch mainly takes the same idea to measure
syscall throughput compatible with 'perf-bench' via getppid(2), yet
without any of the additional template stuff from Ingo's version (based
on numa.c). The code is identical to what mmtests uses.

[0] https://lore.kernel.org/lkml/20160201074156.GA27156@gmail.com/

Committer notes:

Add mising stdlib.h and unistd.h to get the prototypes for exit() and
getppid().

Committer testing:

$ perf bench
Usage:
perf bench [<common options>] <collection> <benchmark> [<options>]

# List of all available benchmark collections:

sched: Scheduler and IPC benchmarks
syscall: System call benchmarks
mem: Memory access benchmarks
numa: NUMA scheduling and MM benchmarks
futex: Futex stressing benchmarks
epoll: Epoll stressing benchmarks
internals: Perf-internals benchmarks
all: All benchmarks

$
$ perf bench syscall

# List of available benchmarks for collection 'syscall':

basic: Benchmark for basic getppid(2) calls
all: Run all syscall benchmarks

$ perf bench syscall basic
# Running 'syscall/basic' benchmark:
# Executed 10000000 getppid() calls
Total time: 3.679 [sec]

0.367957 usecs/op
2717708 ops/sec
$ perf bench syscall all
# Running syscall/basic benchmark...
# Executed 10000000 getppid() calls
Total time: 3.644 [sec]

0.364456 usecs/op
2743815 ops/sec

$

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20190308181747.l36zqz2avtivrr3c@linux-r8p5
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Add event synthesis benchmark

Event synthesis may occur at the start or end (tail) of a perf command.
In system-wide mode it can scan every process in /proc, which may add
seconds of latency before event recording. Add a new benchmark that
times how long event synthesis takes with and without data synthesis.

An example execution looks like:

$ perf bench internals synthesize
# Running 'internals/synthesize' benchmark:
Average synthesis took: 168.253800 usec
Average data synthesis took: 208.104700 usec

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200402154357.107873-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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>

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>

perf bench mem: Rename 'routine' to 'function'

So right now there's a somewhat inconsistent mess of the benchmarking
code and options sometimes calling benchmarked functions 'functions',
sometimes calling them 'routines'.

Name them 'functions' consistently.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445241870-24854-14-git-send-email-mingo@kernel.org
[ Updated perf-bench man page, pointed out by David Ahern ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Harmonize all the -l/--nr_loops options

We have three benchmarking subsystems that specify some sort of 'number
of loops' parameter - but all of them do it inconsistently:

numa: -l/--nr_loops
sched messaging: -l/--loops
mem memset/memcpy: -i/--iterations

Harmonize them to -l/--nr_loops by picking the numa variant - which is
also the most likely one to have existing scripting which we don't want
to break.

Plus improve the parameter help texts to indicate the default value for
the nr_loops variable to keep users from guessing ...

Also propagate the naming to internal variables.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445241870-24854-13-git-send-email-mingo@kernel.org
[ Let the harmonisation reach the perf-bench man page as well ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench mem: Fix 'length' vs. 'size' naming confusion

So 'perf bench mem memcpy/memset' consistently uses 'len' and 'length'
for buffer sizes - while it's really a memory buffer size. (strings have
length.)

Rename all affected variables.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445241870-24854-10-git-send-email-mingo@kernel.org
[ Update perf-bench man page ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench mem: Change 'cycle' to 'cycles'

So 'perf bench mem memset/memcpy' has a CPU cycles measurement method,
but calls it 'cycle' (singular) throughout the code, which makes it
harder to read.

Rename all related functions, variables and options to a plural 'cycles'
nomenclature.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445241870-24854-8-git-send-email-mingo@kernel.org
[ s/--cycle/--cycles/g in perf-bench man page ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Remove the prefaulting complication from 'perf bench mem mem*'

So 'perf bench mem memcpy/memset' has elaborate code to measure
memcpy()/memset() performance both with freshly allocated buffers (which
includes initial page fault overhead) and with preallocated buffers.

But the thing is, the resulting bandwidth results are mostly
meaningless, because page faults dominate so much of the cost.

It might make sense to measure cache cold vs. cache hot performance, but
the code does not do this.

So remove this complication, and always prefault the ranges before using
them.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445241870-24854-6-git-send-email-mingo@kernel.org
[ Remove --no-prefault, --only-prefault from docs, noticed by David Ahern ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench futex: Add lock_pi stresser

Allows a way of measuring low level kernel implementation of FUTEX_LOCK_PI and
FUTEX_UNLOCK_PI.

The program comes in two flavors:

(i) single futex (default), all threads contend on the same uaddr. For the
sake of the benchmark, we call into kernel space even when the lock is
uncontended. The kernel will set it to TID, any waters that come in and
contend for the pi futex will be handled respectively by the kernel.

(ii) -M option for multiple futexes, each thread deals with its own futex. This
is a trivial scenario and only measures kernel handling of 0->TID transition.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1436259353.12255.78.camel@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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>

perf bench: Add --repeat option

There are a number of benchmarks that do single runs and as a result
does not really help users gain a general idea of how the workload
performs. So the user must either manually do multiple runs or just use
single bogus results.

This option will enable users to specify the amount of runs (arbitrarily
defaulted to 10, to use the existing benchmarks default) through the
'--repeat' option. Add it to perf-bench instead of implementing it
always in each specific benchmark.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1402942467-10671-2-git-send-email-davidlohr@hp.com
[ Kept the existing default of 10, changing it to something else should
be done on separate patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Update manpage to mention numa and futex

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1395964219-22173-3-git-send-email-artagnon@gmail.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>

perf bench: Fix confused variable namings and descriptions in mem subsystem

As Namhyung Kim pointed, there are confused namings and descriptions of words
"cycle" and "clock" in mem-memset.c and mem-memcpy.c.

With the option "-c" (or "--clock", now renamed as "--cycle"), mem subsystem
measures cost of memset() and memcpy() with cpu-cycles event.

But current mem subsystem source code contains lots of confused variable
namings and descriptions with "clock" (e.g. the variable use_clock). This is a
very bad style because there is another software event named "cpu-clock". This
patch replaces wrong usage of "clock" to "cycle".

v2: modified Documentation/perf-bench.txt for the descriptions of
--cycle option

Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1341236777-18457-1-git-send-email-h.mitake@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf bench: Documentation update

The current perf-bench documentation has a couple of typos and even
lacks entire description of mem subsystem. Fix it.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340172486-17805-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Fixup minor doc formatting issues

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf: cleanup some Documentation

Correct typos in perf bench & perf sched help text.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100331113100.cc898487.randy.dunlap@oracle.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>

perf bench: Add new document about perf-bench

This patch adds new document about perf-bench.
Man page and html will be provided for user.

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1257853855-28934-3-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>