For memcpy, the source pages are memset to zero only when --cycles is
used. This leads to wildly different results with or without --cycles,
since all sources pages are likely to be mapped to the same zero page
without explicit writes.
Before this fix:
$ export cmd="./perf stat -e LLC-loads -- ./perf bench \
mem memcpy -s 1024MB -l 100 -f default"
$ $cmd
2,935,826 LLC-loads
3.821677452 seconds time elapsed
$ $cmd --cycles
217,533,436 LLC-loads
8.616725985 seconds time elapsed
After this fix:
$ $cmd
214,459,686 LLC-loads
8.674301124 seconds time elapsed
$ $cmd --cycles
214,758,651 LLC-loads
8.644480006 seconds time elapsed
Fixes: 47b5757bac ("perf bench mem: Move boilerplate memory allocation to the infrastructure")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel@axis.com
Link: http://lore.kernel.org/lkml/20200810133404.30829-1-vincent.whitchurch@axis.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by this
change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200515172926.GA31976@embeddedor
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
By default this isn't run as it reads /proc and may not have access.
For consistency, modify the single threaded benchmark to compute an
average time per event.
Committer testing:
$ grep -m1 "model name" /proc/cpuinfo
model name : Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
$ grep "model name" /proc/cpuinfo | wc -l
8
$
$ perf bench internals synthesize -h
# Running 'internals/synthesize' benchmark:
Usage: perf bench internals synthesize <options>
-I, --multi-iterations <n>
Number of iterations used to compute multi-threaded average
-i, --single-iterations <n>
Number of iterations used to compute single-threaded average
-M, --max-threads <n>
Maximum number of threads in multithreaded bench
-m, --min-threads <n>
Minimum number of threads in multithreaded bench
-s, --st Run single threaded benchmark
-t, --mt Run multi-threaded benchmark
$
$ perf bench internals synthesize -t
# Running 'internals/synthesize' benchmark:
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 1
Average synthesis took: 65449.000 usec (+- 586.442 usec)
Average num. events: 9405.400 (+- 0.306)
Average time per event 6.959 usec
Number of synthesis threads: 2
Average synthesis took: 37838.300 usec (+- 130.259 usec)
Average num. events: 9501.800 (+- 20.469)
Average time per event 3.982 usec
Number of synthesis threads: 3
Average synthesis took: 48551.400 usec (+- 225.686 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 5.087 usec
Number of synthesis threads: 4
Average synthesis took: 29632.500 usec (+- 50.808 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 3.105 usec
Number of synthesis threads: 5
Average synthesis took: 33920.400 usec (+- 284.509 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 3.554 usec
Number of synthesis threads: 6
Average synthesis took: 27604.100 usec (+- 72.344 usec)
Average num. events: 9548.000 (+- 0.000)
Average time per event 2.891 usec
Number of synthesis threads: 7
Average synthesis took: 25406.300 usec (+- 933.371 usec)
Average num. events: 9545.500 (+- 0.167)
Average time per event 2.662 usec
Number of synthesis threads: 8
Average synthesis took: 24110.400 usec (+- 73.229 usec)
Average num. events: 9551.000 (+- 0.000)
Average time per event 2.524 usec
$
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
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: 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/20200415054050.31645-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since commit 3b2323c2c1 ("perf bench futex: Use cpumaps") the default
number of threads the benchmark uses got changed from number of online
CPUs to zero:
$ perf bench futex wake
# Running 'futex/wake' benchmark:
Run summary [PID 15930]: blocking on 0 threads (at [private] futex 0x558b8ee4bfac), waking up 1 at a time.
[Run 1]: Wokeup 0 of 0 threads in 0.0000 ms
[...]
[Run 10]: Wokeup 0 of 0 threads in 0.0000 ms
Wokeup 0 of 0 threads in 0.0004 ms (+-40.82%)
Restore the old behavior by grabbing the number of online CPUs via
cpu->nr:
$ perf bench futex wake
# Running 'futex/wake' benchmark:
Run summary [PID 18356]: blocking on 8 threads (at [private] futex 0xb3e62c), waking up 1 at a time.
[Run 1]: Wokeup 8 of 8 threads in 0.0260 ms
[...]
[Run 10]: Wokeup 8 of 8 threads in 0.0270 ms
Wokeup 8 of 8 threads in 0.0419 ms (+-24.35%)
Fixes: 3b2323c2c1 ("perf bench futex: Use cpumaps")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200305083714.9381-3-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Noticed with gcc 10 (fedora rawhide) that those variables were not being
declared as static, so end up with:
ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
make[4]: *** [/git/perf/tools/build/Makefile.build:145: /tmp/build/perf/bench/perf-in.o] Error 1
Prefix those with bench__ and add them to bench/bench.h, so that we can
share those on the tools needing to access those variables from signal
handlers.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200303155811.GD13702@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get closer to upstream and check if we need to sync more UAPI
headers, pick up fixes for libbpf that prevent perf's container tests
from completing successfuly, etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Michael reported an issue with perf bench numa failing with binding to
cpu0 with '-0' option.
# perf bench numa mem -p 3 -t 1 -P 512 -s 100 -zZcm0 --thp 1 -M 1 -ddd
# Running 'numa/mem' benchmark:
# Running main, "perf bench numa numa-mem -p 3 -t 1 -P 512 -s 100 -zZcm0 --thp 1 -M 1 -ddd"
binding to node 0, mask: 0000000000000001 => -1
perf: bench/numa.c:356: bind_to_memnode: Assertion `!(ret)' failed.
Aborted (core dumped)
This happens when the cpu0 is not part of node0, which is the benchmark
assumption and we can see that's not the case for some powerpc servers.
Using correct node for cpu0 binding.
Reported-by: Michael Petlan <mpetlan@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20190801142642.28004-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
