xref: /dpdk/app/test/test_spinlock.c (revision cf435a07)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <stdio.h>
35 #include <stdint.h>
36 #include <inttypes.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <sys/queue.h>
40 
41 #include <rte_common.h>
42 #include <rte_memory.h>
43 #include <rte_memzone.h>
44 #include <rte_per_lcore.h>
45 #include <rte_launch.h>
46 #include <rte_eal.h>
47 #include <rte_per_lcore.h>
48 #include <rte_lcore.h>
49 #include <rte_cycles.h>
50 #include <rte_spinlock.h>
51 #include <rte_atomic.h>
52 
53 #include "test.h"
54 
55 /*
56  * Spinlock test
57  * =============
58  *
59  * - There is a global spinlock and a table of spinlocks (one per lcore).
60  *
61  * - The test function takes all of these locks and launches the
62  *   ``test_spinlock_per_core()`` function on each core (except the master).
63  *
64  *   - The function takes the global lock, display something, then releases
65  *     the global lock.
66  *   - The function takes the per-lcore lock, display something, then releases
67  *     the per-core lock.
68  *
69  * - The main function unlocks the per-lcore locks sequentially and
70  *   waits between each lock. This triggers the display of a message
71  *   for each core, in the correct order. The autotest script checks that
72  *   this order is correct.
73  *
74  * - A load test is carried out, with all cores attempting to lock a single lock
75  *   multiple times
76  */
77 
78 static rte_spinlock_t sl, sl_try;
79 static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
80 static rte_spinlock_recursive_t slr;
81 static unsigned count = 0;
82 
83 static rte_atomic32_t synchro;
84 
85 static int
86 test_spinlock_per_core(__attribute__((unused)) void *arg)
87 {
88 	rte_spinlock_lock(&sl);
89 	printf("Global lock taken on core %u\n", rte_lcore_id());
90 	rte_spinlock_unlock(&sl);
91 
92 	rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
93 	printf("Hello from core %u !\n", rte_lcore_id());
94 	rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);
95 
96 	return 0;
97 }
98 
99 static int
100 test_spinlock_recursive_per_core(__attribute__((unused)) void *arg)
101 {
102 	unsigned id = rte_lcore_id();
103 
104 	rte_spinlock_recursive_lock(&slr);
105 	printf("Global recursive lock taken on core %u - count = %d\n",
106 	       id, slr.count);
107 	rte_spinlock_recursive_lock(&slr);
108 	printf("Global recursive lock taken on core %u - count = %d\n",
109 	       id, slr.count);
110 	rte_spinlock_recursive_lock(&slr);
111 	printf("Global recursive lock taken on core %u - count = %d\n",
112 	       id, slr.count);
113 
114 	printf("Hello from within recursive locks from core %u !\n", id);
115 
116 	rte_spinlock_recursive_unlock(&slr);
117 	printf("Global recursive lock released on core %u - count = %d\n",
118 	       id, slr.count);
119 	rte_spinlock_recursive_unlock(&slr);
120 	printf("Global recursive lock released on core %u - count = %d\n",
121 	       id, slr.count);
122 	rte_spinlock_recursive_unlock(&slr);
123 	printf("Global recursive lock released on core %u - count = %d\n",
124 	       id, slr.count);
125 
126 	return 0;
127 }
128 
129 static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
130 static uint64_t lock_count[RTE_MAX_LCORE] = {0};
131 
132 #define TIME_MS 100
133 
134 static int
135 load_loop_fn(void *func_param)
136 {
137 	uint64_t time_diff = 0, begin;
138 	uint64_t hz = rte_get_timer_hz();
139 	uint64_t lcount = 0;
140 	const int use_lock = *(int*)func_param;
141 	const unsigned lcore = rte_lcore_id();
142 
143 	/* wait synchro for slaves */
144 	if (lcore != rte_get_master_lcore())
145 		while (rte_atomic32_read(&synchro) == 0);
146 
147 	begin = rte_get_timer_cycles();
148 	while (time_diff < hz * TIME_MS / 1000) {
149 		if (use_lock)
150 			rte_spinlock_lock(&lk);
151 		lcount++;
152 		if (use_lock)
153 			rte_spinlock_unlock(&lk);
154 		/* delay to make lock duty cycle slighlty realistic */
155 		rte_delay_us(1);
156 		time_diff = rte_get_timer_cycles() - begin;
157 	}
158 	lock_count[lcore] = lcount;
159 	return 0;
160 }
161 
162 static int
163 test_spinlock_perf(void)
164 {
165 	unsigned int i;
166 	uint64_t total = 0;
167 	int lock = 0;
168 	const unsigned lcore = rte_lcore_id();
169 
170 	printf("\nTest with no lock on single core...\n");
171 	load_loop_fn(&lock);
172 	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
173 	memset(lock_count, 0, sizeof(lock_count));
174 
175 	printf("\nTest with lock on single core...\n");
176 	lock = 1;
177 	load_loop_fn(&lock);
178 	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
179 	memset(lock_count, 0, sizeof(lock_count));
180 
181 	printf("\nTest with lock on %u cores...\n", rte_lcore_count());
182 
183 	/* Clear synchro and start slaves */
184 	rte_atomic32_set(&synchro, 0);
185 	rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
186 
187 	/* start synchro and launch test on master */
188 	rte_atomic32_set(&synchro, 1);
189 	load_loop_fn(&lock);
190 
191 	rte_eal_mp_wait_lcore();
192 
193 	RTE_LCORE_FOREACH(i) {
194 		printf("Core [%u] count = %"PRIu64"\n", i, lock_count[i]);
195 		total += lock_count[i];
196 	}
197 
198 	printf("Total count = %"PRIu64"\n", total);
199 
200 	return 0;
201 }
202 
203 /*
204  * Use rte_spinlock_trylock() to trylock a spinlock object,
205  * If it could not lock the object sucessfully, it would
206  * return immediately and the variable of "count" would be
207  * increased by one per times. the value of "count" could be
208  * checked as the result later.
209  */
210 static int
211 test_spinlock_try(__attribute__((unused)) void *arg)
212 {
213 	if (rte_spinlock_trylock(&sl_try) == 0) {
214 		rte_spinlock_lock(&sl);
215 		count ++;
216 		rte_spinlock_unlock(&sl);
217 	}
218 
219 	return 0;
220 }
221 
222 
223 /*
224  * Test rte_eal_get_lcore_state() in addition to spinlocks
225  * as we have "waiting" then "running" lcores.
226  */
227 static int
228 test_spinlock(void)
229 {
230 	int ret = 0;
231 	int i;
232 
233 	/* slave cores should be waiting: print it */
234 	RTE_LCORE_FOREACH_SLAVE(i) {
235 		printf("lcore %d state: %d\n", i,
236 		       (int) rte_eal_get_lcore_state(i));
237 	}
238 
239 	rte_spinlock_init(&sl);
240 	rte_spinlock_init(&sl_try);
241 	rte_spinlock_recursive_init(&slr);
242 	for (i=0; i<RTE_MAX_LCORE; i++)
243 		rte_spinlock_init(&sl_tab[i]);
244 
245 	rte_spinlock_lock(&sl);
246 
247 	RTE_LCORE_FOREACH_SLAVE(i) {
248 		rte_spinlock_lock(&sl_tab[i]);
249 		rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
250 	}
251 
252 	/* slave cores should be busy: print it */
253 	RTE_LCORE_FOREACH_SLAVE(i) {
254 		printf("lcore %d state: %d\n", i,
255 		       (int) rte_eal_get_lcore_state(i));
256 	}
257 	rte_spinlock_unlock(&sl);
258 
259 	RTE_LCORE_FOREACH_SLAVE(i) {
260 		rte_spinlock_unlock(&sl_tab[i]);
261 		rte_delay_ms(10);
262 	}
263 
264 	rte_eal_mp_wait_lcore();
265 
266 	rte_spinlock_recursive_lock(&slr);
267 
268 	/*
269 	 * Try to acquire a lock that we already own
270 	 */
271 	if(!rte_spinlock_recursive_trylock(&slr)) {
272 		printf("rte_spinlock_recursive_trylock failed on a lock that "
273 		       "we already own\n");
274 		ret = -1;
275 	} else
276 		rte_spinlock_recursive_unlock(&slr);
277 
278 	RTE_LCORE_FOREACH_SLAVE(i) {
279 		rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
280 	}
281 	rte_spinlock_recursive_unlock(&slr);
282 	rte_eal_mp_wait_lcore();
283 
284 	/*
285 	 * Test if it could return immediately from try-locking a locked object.
286 	 * Here it will lock the spinlock object first, then launch all the slave
287 	 * lcores to trylock the same spinlock object.
288 	 * All the slave lcores should give up try-locking a locked object and
289 	 * return immediately, and then increase the "count" initialized with zero
290 	 * by one per times.
291 	 * We can check if the "count" is finally equal to the number of all slave
292 	 * lcores to see if the behavior of try-locking a locked spinlock object
293 	 * is correct.
294 	 */
295 	if (rte_spinlock_trylock(&sl_try) == 0) {
296 		return -1;
297 	}
298 	count = 0;
299 	RTE_LCORE_FOREACH_SLAVE(i) {
300 		rte_eal_remote_launch(test_spinlock_try, NULL, i);
301 	}
302 	rte_eal_mp_wait_lcore();
303 	rte_spinlock_unlock(&sl_try);
304 	if (rte_spinlock_is_locked(&sl)) {
305 		printf("spinlock is locked but it should not be\n");
306 		return -1;
307 	}
308 	rte_spinlock_lock(&sl);
309 	if (count != ( rte_lcore_count() - 1)) {
310 		ret = -1;
311 	}
312 	rte_spinlock_unlock(&sl);
313 
314 	/*
315 	 * Test if it can trylock recursively.
316 	 * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
317 	 * object recursively. Here it will try to lock a spinlock object twice.
318 	 */
319 	if (rte_spinlock_recursive_trylock(&slr) == 0) {
320 		printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
321 		return -1;
322 	}
323 	if (rte_spinlock_recursive_trylock(&slr) == 0) {
324 		printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
325 		return -1;
326 	}
327 	rte_spinlock_recursive_unlock(&slr);
328 	rte_spinlock_recursive_unlock(&slr);
329 
330 	if (test_spinlock_perf() < 0)
331 		return -1;
332 
333 	return ret;
334 }
335 
336 REGISTER_TEST_COMMAND(spinlock_autotest, test_spinlock);
337