linux/tools/perf/bench/sched-pipe.c
Hitoshi Mitake c7d9300f36 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@dcl.info.waseda.ac.jp>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: fweisbec@gmail.com
Cc: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <1257381097-4743-4-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-08 10:19:18 +01:00

114 lines
2.5 KiB
C

/*
*
* builtin-bench-pipe.c
*
* pipe: Benchmark for pipe()
*
* Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
* http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
* Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
*
*/
#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;
}