xref: /dpdk/examples/timer/main.c (revision 3e0ceb9f17fff027fc6c8f18de35e11719ffa61e)
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 <string.h>
36 #include <stdint.h>
37 #include <errno.h>
38 #include <sys/queue.h>
39 
40 #include <rte_common.h>
41 #include <rte_memory.h>
42 #include <rte_launch.h>
43 #include <rte_eal.h>
44 #include <rte_per_lcore.h>
45 #include <rte_lcore.h>
46 #include <rte_cycles.h>
47 #include <rte_timer.h>
48 #include <rte_debug.h>
49 
50 #define TIMER_RESOLUTION_CYCLES 20000000ULL /* around 10ms at 2 Ghz */
51 
52 static struct rte_timer timer0;
53 static struct rte_timer timer1;
54 
55 /* timer0 callback */
56 static void
57 timer0_cb(__attribute__((unused)) struct rte_timer *tim,
58 	  __attribute__((unused)) void *arg)
59 {
60 	static unsigned counter = 0;
61 	unsigned lcore_id = rte_lcore_id();
62 
63 	printf("%s() on lcore %u\n", __func__, lcore_id);
64 
65 	/* this timer is automatically reloaded until we decide to
66 	 * stop it, when counter reaches 20. */
67 	if ((counter ++) == 20)
68 		rte_timer_stop(tim);
69 }
70 
71 /* timer1 callback */
72 static void
73 timer1_cb(__attribute__((unused)) struct rte_timer *tim,
74 	  __attribute__((unused)) void *arg)
75 {
76 	unsigned lcore_id = rte_lcore_id();
77 	uint64_t hz;
78 
79 	printf("%s() on lcore %u\n", __func__, lcore_id);
80 
81 	/* reload it on another lcore */
82 	hz = rte_get_timer_hz();
83 	lcore_id = rte_get_next_lcore(lcore_id, 0, 1);
84 	rte_timer_reset(tim, hz/3, SINGLE, lcore_id, timer1_cb, NULL);
85 }
86 
87 static __attribute__((noreturn)) int
88 lcore_mainloop(__attribute__((unused)) void *arg)
89 {
90 	uint64_t prev_tsc = 0, cur_tsc, diff_tsc;
91 	unsigned lcore_id;
92 
93 	lcore_id = rte_lcore_id();
94 	printf("Starting mainloop on core %u\n", lcore_id);
95 
96 	while (1) {
97 		/*
98 		 * Call the timer handler on each core: as we don't
99 		 * need a very precise timer, so only call
100 		 * rte_timer_manage() every ~10ms (at 2Ghz). In a real
101 		 * application, this will enhance performances as
102 		 * reading the HPET timer is not efficient.
103 		 */
104 		cur_tsc = rte_rdtsc();
105 		diff_tsc = cur_tsc - prev_tsc;
106 		if (diff_tsc > TIMER_RESOLUTION_CYCLES) {
107 			rte_timer_manage();
108 			prev_tsc = cur_tsc;
109 		}
110 	}
111 }
112 
113 int
114 main(int argc, char **argv)
115 {
116 	int ret;
117 	uint64_t hz;
118 	unsigned lcore_id;
119 
120 	/* init EAL */
121 	ret = rte_eal_init(argc, argv);
122 	if (ret < 0)
123 		rte_panic("Cannot init EAL\n");
124 
125 	/* init RTE timer library */
126 	rte_timer_subsystem_init();
127 
128 	/* init timer structures */
129 	rte_timer_init(&timer0);
130 	rte_timer_init(&timer1);
131 
132 	/* load timer0, every second, on master lcore, reloaded automatically */
133 	hz = rte_get_timer_hz();
134 	lcore_id = rte_lcore_id();
135 	rte_timer_reset(&timer0, hz, PERIODICAL, lcore_id, timer0_cb, NULL);
136 
137 	/* load timer1, every second/3, on next lcore, reloaded manually */
138 	lcore_id = rte_get_next_lcore(lcore_id, 0, 1);
139 	rte_timer_reset(&timer1, hz/3, SINGLE, lcore_id, timer1_cb, NULL);
140 
141 	/* call lcore_mainloop() on every slave lcore */
142 	RTE_LCORE_FOREACH_SLAVE(lcore_id) {
143 		rte_eal_remote_launch(lcore_mainloop, NULL, lcore_id);
144 	}
145 
146 	/* call it on master lcore too */
147 	(void) lcore_mainloop(NULL);
148 
149 	return 0;
150 }
151