1/*
2 *
3 * sched-pipe.c
4 *
5 * pipe: Benchmark for pipe()
6 *
7 * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
8 *  http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
9 * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
10 *
11 */
12
13#include "../perf.h"
14#include "../util/util.h"
15#include "../util/parse-options.h"
16#include "../builtin.h"
17#include "bench.h"
18
19#include <unistd.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <signal.h>
23#include <sys/wait.h>
24#include <linux/unistd.h>
25#include <string.h>
26#include <errno.h>
27#include <assert.h>
28#include <sys/time.h>
29#include <sys/types.h>
30
31#define LOOPS_DEFAULT 1000000
32static int loops = LOOPS_DEFAULT;
33
34static const struct option options[] = {
35	OPT_INTEGER('l', "loop", &loops,
36		    "Specify number of loops"),
37	OPT_END()
38};
39
40static const char * const bench_sched_pipe_usage[] = {
41	"perf bench sched pipe <options>",
42	NULL
43};
44
45int bench_sched_pipe(int argc, const char **argv,
46		     const char *prefix __used)
47{
48        /* ANDROID_CHANGE_BEGIN */
49#ifndef __BIONIC__
50	int pipe_1[2], pipe_2[2];
51	int m = 0, i;
52	struct timeval start, stop, diff;
53	unsigned long long result_usec = 0;
54
55	/*
56	 * why does "ret" exist?
57	 * discarding returned value of read(), write()
58	 * causes error in building environment for perf
59	 */
60	int __used ret, wait_stat;
61	pid_t pid, retpid;
62
63	argc = parse_options(argc, argv, options,
64			     bench_sched_pipe_usage, 0);
65
66	assert(!pipe(pipe_1));
67	assert(!pipe(pipe_2));
68
69	pid = fork();
70	assert(pid >= 0);
71
72	gettimeofday(&start, NULL);
73
74	if (!pid) {
75		for (i = 0; i < loops; i++) {
76			ret = read(pipe_1[0], &m, sizeof(int));
77			ret = write(pipe_2[1], &m, sizeof(int));
78		}
79	} else {
80		for (i = 0; i < loops; i++) {
81			ret = write(pipe_1[1], &m, sizeof(int));
82			ret = read(pipe_2[0], &m, sizeof(int));
83		}
84	}
85
86	gettimeofday(&stop, NULL);
87	timersub(&stop, &start, &diff);
88
89	if (pid) {
90		retpid = waitpid(pid, &wait_stat, 0);
91		assert((retpid == pid) && WIFEXITED(wait_stat));
92	} else {
93		exit(0);
94	}
95
96	switch (bench_format) {
97	case BENCH_FORMAT_DEFAULT:
98		printf("# Executed %d pipe operations between two tasks\n\n",
99			loops);
100
101		result_usec = diff.tv_sec * 1000000;
102		result_usec += diff.tv_usec;
103
104		printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
105		       diff.tv_sec,
106		       (unsigned long) (diff.tv_usec/1000));
107
108		printf(" %14lf usecs/op\n",
109		       (double)result_usec / (double)loops);
110		printf(" %14d ops/sec\n",
111		       (int)((double)loops /
112			     ((double)result_usec / (double)1000000)));
113		break;
114
115	case BENCH_FORMAT_SIMPLE:
116		printf("%lu.%03lu\n",
117		       diff.tv_sec,
118		       (unsigned long) (diff.tv_usec / 1000));
119		break;
120
121	default:
122		/* reaching here is something disaster */
123		fprintf(stderr, "Unknown format:%d\n", bench_format);
124		exit(1);
125		break;
126	}
127#endif
128        /* ANDROID_CHANGE_END */
129
130	return 0;
131}
132