xref: /dpdk/app/test/test_mcslock.c (revision 68a03efeed657e6e05f281479b33b51102797e15)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2019 Arm Limited
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_mcslock.h>
20 #include <rte_atomic.h>
21 
22 #include "test.h"
23 
24 /*
25  * RTE MCS lock test
26  * =================
27  *
28  * These tests are derived from spin lock test cases.
29  *
30  * - The functional test takes all of these locks and launches the
31  *   ''test_mcslock_per_core()'' function on each core (except the main).
32  *
33  *   - The function takes the global lock, display something, then releases
34  *     the global lock on each core.
35  *
36  * - A load test is carried out, with all cores attempting to lock a single
37  *   lock multiple times.
38  */
39 
40 rte_mcslock_t *p_ml;
41 rte_mcslock_t *p_ml_try;
42 rte_mcslock_t *p_ml_perf;
43 
44 static unsigned int count;
45 
46 static rte_atomic32_t synchro;
47 
48 static int
49 test_mcslock_per_core(__rte_unused void *arg)
50 {
51 	/* Per core me node. */
52 	rte_mcslock_t ml_me;
53 
54 	rte_mcslock_lock(&p_ml, &ml_me);
55 	printf("MCS lock taken on core %u\n", rte_lcore_id());
56 	rte_mcslock_unlock(&p_ml, &ml_me);
57 	printf("MCS lock released on core %u\n", rte_lcore_id());
58 
59 	return 0;
60 }
61 
62 static uint64_t time_count[RTE_MAX_LCORE] = {0};
63 
64 #define MAX_LOOP 1000000
65 
66 static int
67 load_loop_fn(void *func_param)
68 {
69 	uint64_t time_diff = 0, begin;
70 	uint64_t hz = rte_get_timer_hz();
71 	volatile uint64_t lcount = 0;
72 	const int use_lock = *(int *)func_param;
73 	const unsigned int lcore = rte_lcore_id();
74 
75 	/**< Per core me node. */
76 	rte_mcslock_t ml_perf_me;
77 
78 	/* wait synchro */
79 	while (rte_atomic32_read(&synchro) == 0)
80 		;
81 
82 	begin = rte_get_timer_cycles();
83 	while (lcount < MAX_LOOP) {
84 		if (use_lock)
85 			rte_mcslock_lock(&p_ml_perf, &ml_perf_me);
86 
87 		lcount++;
88 		if (use_lock)
89 			rte_mcslock_unlock(&p_ml_perf, &ml_perf_me);
90 	}
91 	time_diff = rte_get_timer_cycles() - begin;
92 	time_count[lcore] = time_diff * 1000000 / hz;
93 	return 0;
94 }
95 
96 static int
97 test_mcslock_perf(void)
98 {
99 	unsigned int i;
100 	uint64_t total = 0;
101 	int lock = 0;
102 	const unsigned int lcore = rte_lcore_id();
103 
104 	printf("\nTest with no lock on single core...\n");
105 	rte_atomic32_set(&synchro, 1);
106 	load_loop_fn(&lock);
107 	printf("Core [%u] Cost Time = %"PRIu64" us\n",
108 			lcore, time_count[lcore]);
109 	memset(time_count, 0, sizeof(time_count));
110 
111 	printf("\nTest with lock on single core...\n");
112 	lock = 1;
113 	rte_atomic32_set(&synchro, 1);
114 	load_loop_fn(&lock);
115 	printf("Core [%u] Cost Time = %"PRIu64" us\n",
116 			lcore, time_count[lcore]);
117 	memset(time_count, 0, sizeof(time_count));
118 
119 	printf("\nTest with lock on %u cores...\n", (rte_lcore_count()));
120 
121 	rte_atomic32_set(&synchro, 0);
122 	rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN);
123 
124 	/* start synchro and launch test on main */
125 	rte_atomic32_set(&synchro, 1);
126 	load_loop_fn(&lock);
127 
128 	rte_eal_mp_wait_lcore();
129 
130 	RTE_LCORE_FOREACH(i) {
131 		printf("Core [%u] Cost Time = %"PRIu64" us\n",
132 				i, time_count[i]);
133 		total += time_count[i];
134 	}
135 
136 	printf("Total Cost Time = %"PRIu64" us\n", total);
137 
138 	return 0;
139 }
140 
141 /*
142  * Use rte_mcslock_trylock() to trylock a mcs lock object,
143  * If it could not lock the object successfully, it would
144  * return immediately.
145  */
146 static int
147 test_mcslock_try(__rte_unused void *arg)
148 {
149 	/**< Per core me node. */
150 	rte_mcslock_t ml_me;
151 	rte_mcslock_t ml_try_me;
152 
153 	/* Locked ml_try in the main lcore, so it should fail
154 	 * when trying to lock it in the worker lcore.
155 	 */
156 	if (rte_mcslock_trylock(&p_ml_try, &ml_try_me) == 0) {
157 		rte_mcslock_lock(&p_ml, &ml_me);
158 		count++;
159 		rte_mcslock_unlock(&p_ml, &ml_me);
160 	}
161 
162 	return 0;
163 }
164 
165 
166 /*
167  * Test rte_eal_get_lcore_state() in addition to mcs locks
168  * as we have "waiting" then "running" lcores.
169  */
170 static int
171 test_mcslock(void)
172 {
173 	int ret = 0;
174 	int i;
175 
176 	/* Define per core me node. */
177 	rte_mcslock_t ml_me;
178 	rte_mcslock_t ml_try_me;
179 
180 	/*
181 	 * Test mcs lock & unlock on each core
182 	 */
183 
184 	/* worker cores should be waiting: print it */
185 	RTE_LCORE_FOREACH_WORKER(i) {
186 		printf("lcore %d state: %d\n", i,
187 				(int) rte_eal_get_lcore_state(i));
188 	}
189 
190 	rte_mcslock_lock(&p_ml, &ml_me);
191 
192 	RTE_LCORE_FOREACH_WORKER(i) {
193 		rte_eal_remote_launch(test_mcslock_per_core, NULL, i);
194 	}
195 
196 	/* worker cores should be busy: print it */
197 	RTE_LCORE_FOREACH_WORKER(i) {
198 		printf("lcore %d state: %d\n", i,
199 				(int) rte_eal_get_lcore_state(i));
200 	}
201 
202 	rte_mcslock_unlock(&p_ml, &ml_me);
203 
204 	rte_eal_mp_wait_lcore();
205 
206 	/*
207 	 * Test if it could return immediately from try-locking a locked object.
208 	 * Here it will lock the mcs lock object first, then launch all the
209 	 * worker lcores to trylock the same mcs lock object.
210 	 * All the worker lcores should give up try-locking a locked object and
211 	 * return immediately, and then increase the "count" initialized with
212 	 * zero by one per times.
213 	 * We can check if the "count" is finally equal to the number of all
214 	 * worker lcores to see if the behavior of try-locking a locked
215 	 * mcslock object is correct.
216 	 */
217 	if (rte_mcslock_trylock(&p_ml_try, &ml_try_me) == 0)
218 		return -1;
219 
220 	count = 0;
221 	RTE_LCORE_FOREACH_WORKER(i) {
222 		rte_eal_remote_launch(test_mcslock_try, NULL, i);
223 	}
224 	rte_eal_mp_wait_lcore();
225 	rte_mcslock_unlock(&p_ml_try, &ml_try_me);
226 
227 	/* Test is_locked API */
228 	if (rte_mcslock_is_locked(p_ml)) {
229 		printf("mcslock is locked but it should not be\n");
230 		return -1;
231 	}
232 
233 	/* Counting the locked times in each core */
234 	rte_mcslock_lock(&p_ml, &ml_me);
235 	if (count != (rte_lcore_count() - 1))
236 		ret = -1;
237 	rte_mcslock_unlock(&p_ml, &ml_me);
238 
239 	/* mcs lock perf test */
240 	if (test_mcslock_perf() < 0)
241 		return -1;
242 
243 	return ret;
244 }
245 
246 REGISTER_TEST_COMMAND(mcslock_autotest, test_mcslock);
247