xref: /dpdk/app/test/test_timer_racecond.c (revision cf435a07)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2015 Akamai Technologies.
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 "test.h"
35 
36 #include <stdio.h>
37 #include <unistd.h>
38 #include <inttypes.h>
39 #include <rte_cycles.h>
40 #include <rte_timer.h>
41 #include <rte_common.h>
42 #include <rte_lcore.h>
43 #include <rte_random.h>
44 #include <rte_malloc.h>
45 
46 #undef TEST_TIMER_RACECOND_VERBOSE
47 
48 #ifdef RTE_EXEC_ENV_LINUXAPP
49 #define usec_delay(us) usleep(us)
50 #else
51 #define usec_delay(us) rte_delay_us(us)
52 #endif
53 
54 #define BILLION (1UL << 30)
55 
56 #define TEST_DURATION_S 20 /* in seconds */
57 #define N_TIMERS    50
58 
59 static struct rte_timer timer[N_TIMERS];
60 static unsigned timer_lcore_id[N_TIMERS];
61 
62 static unsigned master;
63 static volatile unsigned stop_slaves;
64 
65 static int reload_timer(struct rte_timer *tim);
66 
67 static void
68 timer_cb(struct rte_timer *tim, void *arg __rte_unused)
69 {
70 	/* Simulate slow callback function, 100 us. */
71 	rte_delay_us(100);
72 
73 #ifdef TEST_TIMER_RACECOND_VERBOSE
74 	if (tim == &timer[0])
75 		printf("------------------------------------------------\n");
76 	printf("timer_cb: core %u timer %lu\n",
77 		rte_lcore_id(), tim - timer);
78 #endif
79 	(void)reload_timer(tim);
80 }
81 
82 RTE_DEFINE_PER_LCORE(unsigned, n_reset_collisions);
83 
84 static int
85 reload_timer(struct rte_timer *tim)
86 {
87 	/* Make timer expire roughly when the TSC hits the next BILLION
88 	 * multiple. Add in timer's index to make them expire in nearly
89 	 * sorted order. This makes all timers somewhat synchronized,
90 	 * firing ~2-3 times per second, assuming 2-3 GHz TSCs.
91 	 */
92 	uint64_t ticks = BILLION - (rte_get_timer_cycles() % BILLION) +
93 	    (tim - timer);
94 	int ret;
95 
96 	ret = rte_timer_reset(tim, ticks, PERIODICAL, master, timer_cb, NULL);
97 	if (ret != 0) {
98 #ifdef TEST_TIMER_RACECOND_VERBOSE
99 		printf("- core %u failed to reset timer %lu (OK)\n",
100 			rte_lcore_id(), tim - timer);
101 #endif
102 		RTE_PER_LCORE(n_reset_collisions) += 1;
103 	}
104 	return ret;
105 }
106 
107 static int
108 slave_main_loop(__attribute__((unused)) void *arg)
109 {
110 	unsigned lcore_id = rte_lcore_id();
111 	unsigned i;
112 
113 	RTE_PER_LCORE(n_reset_collisions) = 0;
114 
115 	printf("Starting main loop on core %u\n", lcore_id);
116 
117 	while (!stop_slaves) {
118 		/* Wait until the timer manager is running.
119 		 * We know it's running when we see timer[0] NOT pending.
120 		 */
121 		if (rte_timer_pending(&timer[0])) {
122 			rte_pause();
123 			continue;
124 		}
125 
126 		/* Now, go cause some havoc!
127 		 * Reload our timers.
128 		 */
129 		for (i = 0; i < N_TIMERS; i++) {
130 			if (timer_lcore_id[i] == lcore_id)
131 				(void)reload_timer(&timer[i]);
132 		}
133 		usec_delay(100*1000); /* sleep 100 ms */
134 	}
135 
136 	if (RTE_PER_LCORE(n_reset_collisions) != 0) {
137 		printf("- core %u, %u reset collisions (OK)\n",
138 			lcore_id, RTE_PER_LCORE(n_reset_collisions));
139 	}
140 	return 0;
141 }
142 
143 static int
144 test_timer_racecond(void)
145 {
146 	int ret;
147 	uint64_t hz;
148 	uint64_t cur_time;
149 	uint64_t end_time;
150 	int64_t diff = 0;
151 	unsigned lcore_id;
152 	unsigned i;
153 
154 	master = lcore_id = rte_lcore_id();
155 	hz = rte_get_timer_hz();
156 
157 	/* init and start timers */
158 	for (i = 0; i < N_TIMERS; i++) {
159 		rte_timer_init(&timer[i]);
160 		ret = reload_timer(&timer[i]);
161 		TEST_ASSERT(ret == 0, "reload_timer failed");
162 
163 		/* Distribute timers to slaves.
164 		 * Note that we assign timer[0] to the master.
165 		 */
166 		timer_lcore_id[i] = lcore_id;
167 		lcore_id = rte_get_next_lcore(lcore_id, 1, 1);
168 	}
169 
170 	/* calculate the "end of test" time */
171 	cur_time = rte_get_timer_cycles();
172 	end_time = cur_time + (hz * TEST_DURATION_S);
173 
174 	/* start slave cores */
175 	stop_slaves = 0;
176 	printf("Start timer manage race condition test (%u seconds)\n",
177 			TEST_DURATION_S);
178 	rte_eal_mp_remote_launch(slave_main_loop, NULL, SKIP_MASTER);
179 
180 	while (diff >= 0) {
181 		/* run the timers */
182 		rte_timer_manage();
183 
184 		/* wait 100 ms */
185 		usec_delay(100*1000);
186 
187 		cur_time = rte_get_timer_cycles();
188 		diff = end_time - cur_time;
189 	}
190 
191 	/* stop slave cores */
192 	printf("Stopping timer manage race condition test\n");
193 	stop_slaves = 1;
194 	rte_eal_mp_wait_lcore();
195 
196 	/* stop timers */
197 	for (i = 0; i < N_TIMERS; i++) {
198 		ret = rte_timer_stop(&timer[i]);
199 		TEST_ASSERT(ret == 0, "rte_timer_stop failed");
200 	}
201 
202 	return TEST_SUCCESS;
203 }
204 
205 REGISTER_TEST_COMMAND(timer_racecond_autotest, test_timer_racecond);
206