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>
diff --git a/tools/perf/bench/syscall.c b/tools/perf/bench/syscall.c
new file mode 100644
index 0000000..5fe621c
--- /dev/null
+++ b/tools/perf/bench/syscall.c
@@ -0,0 +1,81 @@
+/*
+ *
+ * syscall.c
+ *
+ * syscall: Benchmark for system call performance
+ */
+#include "../perf.h"
+#include "../util/util.h"
+#include <subcmd/parse-options.h>
+#include "../builtin.h"
+#include "bench.h"
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#define LOOPS_DEFAULT 10000000
+static int loops = LOOPS_DEFAULT;
+
+static const struct option options[] = {
+ OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
+ OPT_END()
+};
+
+static const char * const bench_syscall_usage[] = {
+ "perf bench syscall <options>",
+ NULL
+};
+
+int bench_syscall_basic(int argc, const char **argv)
+{
+ struct timeval start, stop, diff;
+ unsigned long long result_usec = 0;
+ int i;
+
+ argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
+
+ gettimeofday(&start, NULL);
+
+ for (i = 0; i < loops; i++)
+ getppid();
+
+ gettimeofday(&stop, NULL);
+ timersub(&stop, &start, &diff);
+
+ switch (bench_format) {
+ case BENCH_FORMAT_DEFAULT:
+ printf("# Executed %'d getppid() calls\n", loops);
+
+ result_usec = diff.tv_sec * 1000000;
+ result_usec += diff.tv_usec;
+
+ printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
+ diff.tv_sec,
+ (unsigned long) (diff.tv_usec/1000));
+
+ printf(" %14lf usecs/op\n",
+ (double)result_usec / (double)loops);
+ printf(" %'14d ops/sec\n",
+ (int)((double)loops /
+ ((double)result_usec / (double)1000000)));
+ break;
+
+ case BENCH_FORMAT_SIMPLE:
+ printf("%lu.%03lu\n",
+ diff.tv_sec,
+ (unsigned long) (diff.tv_usec / 1000));
+ break;
+
+ default:
+ /* reaching here is something disaster */
+ fprintf(stderr, "Unknown format:%d\n", bench_format);
+ exit(1);
+ break;
+ }
+
+ return 0;
+}