1 #include "qemu/osdep.h"
2 #include "qemu/thread.h"
3 #include "qemu/host-utils.h"
4 #include "qemu/processor.h"
5 #include "qemu/memalign.h"
6
7 struct thread_info {
8 uint64_t r;
9 } QEMU_ALIGNED(64);
10
11 struct count {
12 QemuMutex lock;
13 unsigned long val;
14 } QEMU_ALIGNED(64);
15
16 static QemuThread *threads;
17 static struct thread_info *th_info;
18 static unsigned int n_threads = 1;
19 static unsigned int n_ready_threads;
20 static struct count *counts;
21 static unsigned int duration = 1;
22 static unsigned int range = 1024;
23 static bool use_mutex;
24 static bool test_start;
25 static bool test_stop;
26
27 static const char commands_string[] =
28 " -n = number of threads\n"
29 " -m = use mutexes instead of atomic increments\n"
30 " -p = enable sync profiler\n"
31 " -d = duration in seconds\n"
32 " -r = range (will be rounded up to pow2)";
33
usage_complete(char * argv[])34 static void usage_complete(char *argv[])
35 {
36 fprintf(stderr, "Usage: %s [options]\n", argv[0]);
37 fprintf(stderr, "options:\n%s\n", commands_string);
38 }
39
40 /*
41 * From: https://en.wikipedia.org/wiki/Xorshift
42 * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only
43 * guaranteed to be >= INT_MAX).
44 */
xorshift64star(uint64_t x)45 static uint64_t xorshift64star(uint64_t x)
46 {
47 x ^= x >> 12; /* a */
48 x ^= x << 25; /* b */
49 x ^= x >> 27; /* c */
50 return x * UINT64_C(2685821657736338717);
51 }
52
thread_func(void * arg)53 static void *thread_func(void *arg)
54 {
55 struct thread_info *info = arg;
56
57 qatomic_inc(&n_ready_threads);
58 while (!qatomic_read(&test_start)) {
59 cpu_relax();
60 }
61
62 while (!qatomic_read(&test_stop)) {
63 unsigned int index;
64
65 info->r = xorshift64star(info->r);
66 index = info->r & (range - 1);
67 if (use_mutex) {
68 qemu_mutex_lock(&counts[index].lock);
69 counts[index].val += 1;
70 qemu_mutex_unlock(&counts[index].lock);
71 } else {
72 qatomic_inc(&counts[index].val);
73 }
74 }
75 return NULL;
76 }
77
run_test(void)78 static void run_test(void)
79 {
80 unsigned int i;
81
82 while (qatomic_read(&n_ready_threads) != n_threads) {
83 cpu_relax();
84 }
85
86 qatomic_set(&test_start, true);
87 g_usleep(duration * G_USEC_PER_SEC);
88 qatomic_set(&test_stop, true);
89
90 for (i = 0; i < n_threads; i++) {
91 qemu_thread_join(&threads[i]);
92 }
93 }
94
create_threads(void)95 static void create_threads(void)
96 {
97 unsigned int i;
98
99 threads = g_new(QemuThread, n_threads);
100 th_info = g_new(struct thread_info, n_threads);
101 counts = qemu_memalign(64, sizeof(*counts) * range);
102 memset(counts, 0, sizeof(*counts) * range);
103 for (i = 0; i < range; i++) {
104 qemu_mutex_init(&counts[i].lock);
105 }
106
107 for (i = 0; i < n_threads; i++) {
108 struct thread_info *info = &th_info[i];
109
110 info->r = (i + 1) ^ time(NULL);
111 qemu_thread_create(&threads[i], NULL, thread_func, info,
112 QEMU_THREAD_JOINABLE);
113 }
114 }
115
pr_params(void)116 static void pr_params(void)
117 {
118 printf("Parameters:\n");
119 printf(" # of threads: %u\n", n_threads);
120 printf(" duration: %u\n", duration);
121 printf(" ops' range: %u\n", range);
122 }
123
pr_stats(void)124 static void pr_stats(void)
125 {
126 unsigned long long val = 0;
127 unsigned int i;
128 double tx;
129
130 for (i = 0; i < range; i++) {
131 val += counts[i].val;
132 }
133 tx = val / duration / 1e6;
134
135 printf("Results:\n");
136 printf("Duration: %u s\n", duration);
137 printf(" Throughput: %.2f Mops/s\n", tx);
138 printf(" Throughput/thread: %.2f Mops/s/thread\n", tx / n_threads);
139 }
140
parse_args(int argc,char * argv[])141 static void parse_args(int argc, char *argv[])
142 {
143 int c;
144
145 for (;;) {
146 c = getopt(argc, argv, "hd:n:mpr:");
147 if (c < 0) {
148 break;
149 }
150 switch (c) {
151 case 'h':
152 usage_complete(argv);
153 exit(0);
154 case 'd':
155 duration = atoi(optarg);
156 break;
157 case 'n':
158 n_threads = atoi(optarg);
159 break;
160 case 'm':
161 use_mutex = true;
162 break;
163 case 'p':
164 qsp_enable();
165 break;
166 case 'r':
167 range = pow2ceil(atoi(optarg));
168 break;
169 }
170 }
171 }
172
main(int argc,char * argv[])173 int main(int argc, char *argv[])
174 {
175 parse_args(argc, argv);
176 pr_params();
177 create_threads();
178 run_test();
179 pr_stats();
180 return 0;
181 }
182