xref: /dpdk/app/test/test_mcslock.c (revision b6a7e6852e9ab82ae0e05e2d2a0b83abca17de3b)
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 
21 #include "test.h"
22 
23 /*
24  * RTE MCS lock test
25  * =================
26  *
27  * These tests are derived from spin lock test cases.
28  *
29  * - The functional test takes all of these locks and launches the
30  *   ''test_mcslock_per_core()'' function on each core (except the main).
31  *
32  *   - The function takes the global lock, display something, then releases
33  *     the global lock on each core.
34  *
35  * - A load test is carried out, with all cores attempting to lock a single
36  *   lock multiple times.
37  */
38 
39 RTE_ATOMIC(rte_mcslock_t *) p_ml;
40 RTE_ATOMIC(rte_mcslock_t *) p_ml_try;
41 RTE_ATOMIC(rte_mcslock_t *) p_ml_perf;
42 
43 static unsigned int count;
44 
45 static RTE_ATOMIC(uint32_t) synchro;
46 
47 static int
test_mcslock_per_core(__rte_unused void * arg)48 test_mcslock_per_core(__rte_unused void *arg)
49 {
50 	/* Per core me node. */
51 	rte_mcslock_t ml_me;
52 
53 	rte_mcslock_lock(&p_ml, &ml_me);
54 	printf("MCS lock taken on core %u\n", rte_lcore_id());
55 	rte_mcslock_unlock(&p_ml, &ml_me);
56 	printf("MCS lock released on core %u\n", rte_lcore_id());
57 
58 	return 0;
59 }
60 
61 static uint64_t time_count[RTE_MAX_LCORE] = {0};
62 
63 #define MAX_LOOP 1000000
64 
65 static int
load_loop_fn(void * func_param)66 load_loop_fn(void *func_param)
67 {
68 	uint64_t time_diff = 0, begin;
69 	uint64_t hz = rte_get_timer_hz();
70 	volatile uint64_t lcount = 0;
71 	const int use_lock = *(int *)func_param;
72 	const unsigned int lcore = rte_lcore_id();
73 
74 	/**< Per core me node. */
75 	rte_mcslock_t ml_perf_me;
76 
77 	/* wait synchro */
78 	rte_wait_until_equal_32((uint32_t *)(uintptr_t)&synchro, 1, rte_memory_order_relaxed);
79 
80 	begin = rte_get_timer_cycles();
81 	while (lcount < MAX_LOOP) {
82 		if (use_lock)
83 			rte_mcslock_lock(&p_ml_perf, &ml_perf_me);
84 
85 		lcount++;
86 		if (use_lock)
87 			rte_mcslock_unlock(&p_ml_perf, &ml_perf_me);
88 	}
89 	time_diff = rte_get_timer_cycles() - begin;
90 	time_count[lcore] = time_diff * 1000000 / hz;
91 	return 0;
92 }
93 
94 static int
test_mcslock_perf(void)95 test_mcslock_perf(void)
96 {
97 	unsigned int i;
98 	uint64_t total = 0;
99 	int lock = 0;
100 	const unsigned int lcore = rte_lcore_id();
101 
102 	printf("\nTest with no lock on single core...\n");
103 	rte_atomic_store_explicit(&synchro, 1, rte_memory_order_relaxed);
104 	load_loop_fn(&lock);
105 	printf("Core [%u] Cost Time = %"PRIu64" us\n",
106 			lcore, time_count[lcore]);
107 	memset(time_count, 0, sizeof(time_count));
108 
109 	printf("\nTest with lock on single core...\n");
110 	rte_atomic_store_explicit(&synchro, 1, rte_memory_order_relaxed);
111 	lock = 1;
112 	load_loop_fn(&lock);
113 	printf("Core [%u] Cost Time = %"PRIu64" us\n",
114 			lcore, time_count[lcore]);
115 	memset(time_count, 0, sizeof(time_count));
116 
117 	printf("\nTest with lock on %u cores...\n", (rte_lcore_count()));
118 
119 	rte_atomic_store_explicit(&synchro, 0, rte_memory_order_relaxed);
120 	rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN);
121 
122 	/* start synchro and launch test on main */
123 	rte_atomic_store_explicit(&synchro, 1, rte_memory_order_relaxed);
124 	load_loop_fn(&lock);
125 
126 	rte_eal_mp_wait_lcore();
127 
128 	RTE_LCORE_FOREACH(i) {
129 		printf("Core [%u] Cost Time = %"PRIu64" us\n",
130 				i, time_count[i]);
131 		total += time_count[i];
132 	}
133 
134 	printf("Total Cost Time = %"PRIu64" us\n", total);
135 
136 	return 0;
137 }
138 
139 /*
140  * Use rte_mcslock_trylock() to trylock a mcs lock object,
141  * If it could not lock the object successfully, it would
142  * return immediately.
143  */
144 static int
test_mcslock_try(__rte_unused void * arg)145 test_mcslock_try(__rte_unused void *arg)
146 {
147 	/**< Per core me node. */
148 	rte_mcslock_t ml_me;
149 	rte_mcslock_t ml_try_me;
150 
151 	/* Locked ml_try in the main lcore, so it should fail
152 	 * when trying to lock it in the worker lcore.
153 	 */
154 	if (rte_mcslock_trylock(&p_ml_try, &ml_try_me) == 0) {
155 		rte_mcslock_lock(&p_ml, &ml_me);
156 		count++;
157 		rte_mcslock_unlock(&p_ml, &ml_me);
158 	}
159 
160 	return 0;
161 }
162 
163 
164 /*
165  * Test rte_eal_get_lcore_state() in addition to mcs locks
166  * as we have "waiting" then "running" lcores.
167  */
168 static int
test_mcslock(void)169 test_mcslock(void)
170 {
171 	int ret = 0;
172 	int i;
173 
174 	/* Define per core me node. */
175 	rte_mcslock_t ml_me;
176 	rte_mcslock_t ml_try_me;
177 
178 	/*
179 	 * Test mcs lock & unlock on each core
180 	 */
181 
182 	/* worker cores should be waiting: print it */
183 	RTE_LCORE_FOREACH_WORKER(i) {
184 		printf("lcore %d state: %d\n", i,
185 				(int) rte_eal_get_lcore_state(i));
186 	}
187 
188 	rte_mcslock_lock(&p_ml, &ml_me);
189 
190 	RTE_LCORE_FOREACH_WORKER(i) {
191 		rte_eal_remote_launch(test_mcslock_per_core, NULL, i);
192 	}
193 
194 	/* worker cores should be busy: print it */
195 	RTE_LCORE_FOREACH_WORKER(i) {
196 		printf("lcore %d state: %d\n", i,
197 				(int) rte_eal_get_lcore_state(i));
198 	}
199 
200 	rte_mcslock_unlock(&p_ml, &ml_me);
201 
202 	rte_eal_mp_wait_lcore();
203 
204 	/*
205 	 * Test if it could return immediately from try-locking a locked object.
206 	 * Here it will lock the mcs lock object first, then launch all the
207 	 * worker lcores to trylock the same mcs lock object.
208 	 * All the worker lcores should give up try-locking a locked object and
209 	 * return immediately, and then increase the "count" initialized with
210 	 * zero by one per times.
211 	 * We can check if the "count" is finally equal to the number of all
212 	 * worker lcores to see if the behavior of try-locking a locked
213 	 * mcslock object is correct.
214 	 */
215 	if (rte_mcslock_trylock(&p_ml_try, &ml_try_me) == 0)
216 		return -1;
217 
218 	count = 0;
219 	RTE_LCORE_FOREACH_WORKER(i) {
220 		rte_eal_remote_launch(test_mcslock_try, NULL, i);
221 	}
222 	rte_eal_mp_wait_lcore();
223 	rte_mcslock_unlock(&p_ml_try, &ml_try_me);
224 
225 	/* Test is_locked API */
226 	if (rte_mcslock_is_locked(p_ml)) {
227 		printf("mcslock is locked but it should not be\n");
228 		return -1;
229 	}
230 
231 	/* Counting the locked times in each core */
232 	rte_mcslock_lock(&p_ml, &ml_me);
233 	if (count != (rte_lcore_count() - 1))
234 		ret = -1;
235 	rte_mcslock_unlock(&p_ml, &ml_me);
236 
237 	/* mcs lock perf test */
238 	if (test_mcslock_perf() < 0)
239 		return -1;
240 
241 	return ret;
242 }
243 
244 REGISTER_FAST_TEST(mcslock_autotest, false, true, test_mcslock);
245