xref: /dpdk/app/test/test_spinlock.c (revision 742bde12)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include <stdio.h>
6 #include <stdint.h>
7 #include <inttypes.h>
8 #include <string.h>
9 #include <unistd.h>
10 #include <sys/queue.h>
11 
12 #include <rte_common.h>
13 #include <rte_memory.h>
14 #include <rte_per_lcore.h>
15 #include <rte_launch.h>
16 #include <rte_eal.h>
17 #include <rte_lcore.h>
18 #include <rte_cycles.h>
19 #include <rte_spinlock.h>
20 #include <rte_atomic.h>
21 
22 #include "test.h"
23 
24 /*
25  * Spinlock test
26  * =============
27  *
28  * - There is a global spinlock and a table of spinlocks (one per lcore).
29  *
30  * - The test function takes all of these locks and launches the
31  *   ``test_spinlock_per_core()`` function on each core (except the master).
32  *
33  *   - The function takes the global lock, display something, then releases
34  *     the global lock.
35  *   - The function takes the per-lcore lock, display something, then releases
36  *     the per-core lock.
37  *
38  * - The main function unlocks the per-lcore locks sequentially and
39  *   waits between each lock. This triggers the display of a message
40  *   for each core, in the correct order. The autotest script checks that
41  *   this order is correct.
42  *
43  * - A load test is carried out, with all cores attempting to lock a single lock
44  *   multiple times
45  */
46 
47 static rte_spinlock_t sl, sl_try;
48 static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
49 static rte_spinlock_recursive_t slr;
50 static unsigned count = 0;
51 
52 static rte_atomic32_t synchro;
53 
54 static int
55 test_spinlock_per_core(__attribute__((unused)) void *arg)
56 {
57 	rte_spinlock_lock(&sl);
58 	printf("Global lock taken on core %u\n", rte_lcore_id());
59 	rte_spinlock_unlock(&sl);
60 
61 	rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
62 	printf("Hello from core %u !\n", rte_lcore_id());
63 	rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);
64 
65 	return 0;
66 }
67 
68 static int
69 test_spinlock_recursive_per_core(__attribute__((unused)) void *arg)
70 {
71 	unsigned id = rte_lcore_id();
72 
73 	rte_spinlock_recursive_lock(&slr);
74 	printf("Global recursive lock taken on core %u - count = %d\n",
75 	       id, slr.count);
76 	rte_spinlock_recursive_lock(&slr);
77 	printf("Global recursive lock taken on core %u - count = %d\n",
78 	       id, slr.count);
79 	rte_spinlock_recursive_lock(&slr);
80 	printf("Global recursive lock taken on core %u - count = %d\n",
81 	       id, slr.count);
82 
83 	printf("Hello from within recursive locks from core %u !\n", id);
84 
85 	rte_spinlock_recursive_unlock(&slr);
86 	printf("Global recursive lock released on core %u - count = %d\n",
87 	       id, slr.count);
88 	rte_spinlock_recursive_unlock(&slr);
89 	printf("Global recursive lock released on core %u - count = %d\n",
90 	       id, slr.count);
91 	rte_spinlock_recursive_unlock(&slr);
92 	printf("Global recursive lock released on core %u - count = %d\n",
93 	       id, slr.count);
94 
95 	return 0;
96 }
97 
98 static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
99 static uint64_t lock_count[RTE_MAX_LCORE] = {0};
100 
101 #define TIME_MS 100
102 
103 static int
104 load_loop_fn(void *func_param)
105 {
106 	uint64_t time_diff = 0, begin;
107 	uint64_t hz = rte_get_timer_hz();
108 	uint64_t lcount = 0;
109 	const int use_lock = *(int*)func_param;
110 	const unsigned lcore = rte_lcore_id();
111 
112 	/* wait synchro for slaves */
113 	if (lcore != rte_get_master_lcore())
114 		while (rte_atomic32_read(&synchro) == 0);
115 
116 	begin = rte_get_timer_cycles();
117 	while (time_diff < hz * TIME_MS / 1000) {
118 		if (use_lock)
119 			rte_spinlock_lock(&lk);
120 		lcount++;
121 		if (use_lock)
122 			rte_spinlock_unlock(&lk);
123 		/* delay to make lock duty cycle slighlty realistic */
124 		rte_delay_us(1);
125 		time_diff = rte_get_timer_cycles() - begin;
126 	}
127 	lock_count[lcore] = lcount;
128 	return 0;
129 }
130 
131 static int
132 test_spinlock_perf(void)
133 {
134 	unsigned int i;
135 	uint64_t total = 0;
136 	int lock = 0;
137 	const unsigned lcore = rte_lcore_id();
138 
139 	printf("\nTest with no lock on single core...\n");
140 	load_loop_fn(&lock);
141 	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
142 	memset(lock_count, 0, sizeof(lock_count));
143 
144 	printf("\nTest with lock on single core...\n");
145 	lock = 1;
146 	load_loop_fn(&lock);
147 	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
148 	memset(lock_count, 0, sizeof(lock_count));
149 
150 	printf("\nTest with lock on %u cores...\n", rte_lcore_count());
151 
152 	/* Clear synchro and start slaves */
153 	rte_atomic32_set(&synchro, 0);
154 	rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
155 
156 	/* start synchro and launch test on master */
157 	rte_atomic32_set(&synchro, 1);
158 	load_loop_fn(&lock);
159 
160 	rte_eal_mp_wait_lcore();
161 
162 	RTE_LCORE_FOREACH(i) {
163 		printf("Core [%u] count = %"PRIu64"\n", i, lock_count[i]);
164 		total += lock_count[i];
165 	}
166 
167 	printf("Total count = %"PRIu64"\n", total);
168 
169 	return 0;
170 }
171 
172 /*
173  * Use rte_spinlock_trylock() to trylock a spinlock object,
174  * If it could not lock the object successfully, it would
175  * return immediately and the variable of "count" would be
176  * increased by one per times. the value of "count" could be
177  * checked as the result later.
178  */
179 static int
180 test_spinlock_try(__attribute__((unused)) void *arg)
181 {
182 	if (rte_spinlock_trylock(&sl_try) == 0) {
183 		rte_spinlock_lock(&sl);
184 		count ++;
185 		rte_spinlock_unlock(&sl);
186 	}
187 
188 	return 0;
189 }
190 
191 
192 /*
193  * Test rte_eal_get_lcore_state() in addition to spinlocks
194  * as we have "waiting" then "running" lcores.
195  */
196 static int
197 test_spinlock(void)
198 {
199 	int ret = 0;
200 	int i;
201 
202 	/* slave cores should be waiting: print it */
203 	RTE_LCORE_FOREACH_SLAVE(i) {
204 		printf("lcore %d state: %d\n", i,
205 		       (int) rte_eal_get_lcore_state(i));
206 	}
207 
208 	rte_spinlock_init(&sl);
209 	rte_spinlock_init(&sl_try);
210 	rte_spinlock_recursive_init(&slr);
211 	for (i=0; i<RTE_MAX_LCORE; i++)
212 		rte_spinlock_init(&sl_tab[i]);
213 
214 	rte_spinlock_lock(&sl);
215 
216 	RTE_LCORE_FOREACH_SLAVE(i) {
217 		rte_spinlock_lock(&sl_tab[i]);
218 		rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
219 	}
220 
221 	/* slave cores should be busy: print it */
222 	RTE_LCORE_FOREACH_SLAVE(i) {
223 		printf("lcore %d state: %d\n", i,
224 		       (int) rte_eal_get_lcore_state(i));
225 	}
226 	rte_spinlock_unlock(&sl);
227 
228 	RTE_LCORE_FOREACH_SLAVE(i) {
229 		rte_spinlock_unlock(&sl_tab[i]);
230 		rte_delay_ms(10);
231 	}
232 
233 	rte_eal_mp_wait_lcore();
234 
235 	rte_spinlock_recursive_lock(&slr);
236 
237 	/*
238 	 * Try to acquire a lock that we already own
239 	 */
240 	if(!rte_spinlock_recursive_trylock(&slr)) {
241 		printf("rte_spinlock_recursive_trylock failed on a lock that "
242 		       "we already own\n");
243 		ret = -1;
244 	} else
245 		rte_spinlock_recursive_unlock(&slr);
246 
247 	RTE_LCORE_FOREACH_SLAVE(i) {
248 		rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
249 	}
250 	rte_spinlock_recursive_unlock(&slr);
251 	rte_eal_mp_wait_lcore();
252 
253 	/*
254 	 * Test if it could return immediately from try-locking a locked object.
255 	 * Here it will lock the spinlock object first, then launch all the slave
256 	 * lcores to trylock the same spinlock object.
257 	 * All the slave lcores should give up try-locking a locked object and
258 	 * return immediately, and then increase the "count" initialized with zero
259 	 * by one per times.
260 	 * We can check if the "count" is finally equal to the number of all slave
261 	 * lcores to see if the behavior of try-locking a locked spinlock object
262 	 * is correct.
263 	 */
264 	if (rte_spinlock_trylock(&sl_try) == 0) {
265 		return -1;
266 	}
267 	count = 0;
268 	RTE_LCORE_FOREACH_SLAVE(i) {
269 		rte_eal_remote_launch(test_spinlock_try, NULL, i);
270 	}
271 	rte_eal_mp_wait_lcore();
272 	rte_spinlock_unlock(&sl_try);
273 	if (rte_spinlock_is_locked(&sl)) {
274 		printf("spinlock is locked but it should not be\n");
275 		return -1;
276 	}
277 	rte_spinlock_lock(&sl);
278 	if (count != ( rte_lcore_count() - 1)) {
279 		ret = -1;
280 	}
281 	rte_spinlock_unlock(&sl);
282 
283 	/*
284 	 * Test if it can trylock recursively.
285 	 * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
286 	 * object recursively. Here it will try to lock a spinlock object twice.
287 	 */
288 	if (rte_spinlock_recursive_trylock(&slr) == 0) {
289 		printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
290 		return -1;
291 	}
292 	if (rte_spinlock_recursive_trylock(&slr) == 0) {
293 		printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
294 		return -1;
295 	}
296 	rte_spinlock_recursive_unlock(&slr);
297 	rte_spinlock_recursive_unlock(&slr);
298 
299 	if (test_spinlock_perf() < 0)
300 		return -1;
301 
302 	return ret;
303 }
304 
305 REGISTER_TEST_COMMAND(spinlock_autotest, test_spinlock);
306