[tip:perf/bench] perf bench: Add sched-pipe.c: Benchmark for pipe() system call

From: tip-bot for Hitoshi Mitake
Date: Sun Nov 08 2009 - 04:26:17 EST


Commit-ID: c7d9300f367f480aee4663a0e3695c5b48859a1a
Gitweb: http://git.kernel.org/tip/c7d9300f367f480aee4663a0e3695c5b48859a1a
Author: Hitoshi Mitake <mitake@xxxxxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 5 Nov 2009 09:31:33 +0900
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sun, 8 Nov 2009 10:19:18 +0100

perf bench: Add sched-pipe.c: Benchmark for pipe() system call

This patch adds bench/sched-pipe.c.

bench/sched-pipe.c is a benchmark program
to measure performance of pipe() system call.
This benchmark is based on pipe-test-1m.c by Ingo Molnar:

http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c

Example of use:

% perf bench sched pipe
(executing 1000000 pipe operations between two tasks)

Total time:4.499 sec
4.499179 usecs/op
222262 ops/sec

% perf bench sched pipe -s -l 1000
0.015

Signed-off-by: Hitoshi Mitake <mitake@xxxxxxxxxxxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: fweisbec@xxxxxxxxx
Cc: Jiri Kosina <jkosina@xxxxxxx>
LKML-Reference: <1257381097-4743-4-git-send-email-mitake@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
tools/perf/bench/sched-pipe.c | 113 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 113 insertions(+), 0 deletions(-)

diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
new file mode 100644
index 0000000..3214ed2
--- /dev/null
+++ b/tools/perf/bench/sched-pipe.c
@@ -0,0 +1,113 @@
+/*
+ *
+ * builtin-bench-pipe.c
+ *
+ * pipe: Benchmark for pipe()
+ *
+ * Based on pipe-test-1m.c by Ingo Molnar <mingo@xxxxxxxxxx>
+ * http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
+ * Ported to perf by Hitoshi Mitake <mitake@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ */
+
+#include "../perf.h"
+#include "../util/util.h"
+#include "../util/parse-options.h"
+#include "../builtin.h"
+#include "bench.h"
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <linux/unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/time.h>
+
+#define LOOPS_DEFAULT 1000000
+static int loops = LOOPS_DEFAULT;
+static int simple = 0;
+
+static const struct option options[] = {
+ OPT_INTEGER('l', "loop", &loops,
+ "Specify number of loops"),
+ OPT_BOOLEAN('s', "simple-output", &simple,
+ "Do simple output (this maybe useful for"
+ "processing by scripts or graph tools like gnuplot)"),
+ OPT_END()
+};
+
+static const char * const bench_sched_pipe_usage[] = {
+ "perf bench sched pipe <options>",
+ NULL
+};
+
+int bench_sched_pipe(int argc, const char **argv,
+ const char *prefix __used)
+{
+ int pipe_1[2], pipe_2[2];
+ int m = 0, i;
+ struct timeval start, stop, diff;
+ unsigned long long result_usec = 0;
+
+ /*
+ * why does "ret" exist?
+ * discarding returned value of read(), write()
+ * causes error in building environment for perf
+ */
+ int ret;
+ pid_t pid;
+
+ argc = parse_options(argc, argv, options,
+ bench_sched_pipe_usage, 0);
+
+ assert(!pipe(pipe_1));
+ assert(!pipe(pipe_2));
+
+ pid = fork();
+ assert(pid >= 0);
+
+ gettimeofday(&start, NULL);
+
+ if (!pid) {
+ for (i = 0; i < loops; i++) {
+ ret = read(pipe_1[0], &m, sizeof(int));
+ ret = write(pipe_2[1], &m, sizeof(int));
+ }
+ } else {
+ for (i = 0; i < loops; i++) {
+ ret = write(pipe_1[1], &m, sizeof(int));
+ ret = read(pipe_2[0], &m, sizeof(int));
+ }
+ }
+
+ gettimeofday(&stop, NULL);
+ timersub(&stop, &start, &diff);
+
+ if (pid)
+ return 0;
+
+ if (simple)
+ printf("%lu.%03lu\n",
+ diff.tv_sec, diff.tv_usec / 1000);
+ else {
+ printf("(executing %d pipe operations between two tasks)\n\n",
+ loops);
+
+ result_usec = diff.tv_sec * 1000000;
+ result_usec += diff.tv_usec;
+
+ printf("\tTotal time:%lu.%03lu sec\n",
+ diff.tv_sec, diff.tv_usec / 1000);
+ printf("\t\t%lf usecs/op\n",
+ (double)result_usec / (double)loops);
+ printf("\t\t%d ops/sec\n",
+ (int)((double)loops /
+ ((double)result_usec / (double)1000000)));
+ }
+
+ return 0;
+}
--
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