aboutsummaryrefslogtreecommitdiffstats
path: root/lib/librte_eal/linuxapp/eal/eal_thread.c
blob: c3947d731c418556719f4e9d2f140bcf45e73196 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <pthread.h>
#include <sched.h>
#include <sys/queue.h>
#include <sys/syscall.h>

#include <rte_debug.h>
#include <rte_atomic.h>
#include <rte_launch.h>
#include <rte_log.h>
#include <rte_memory.h>
#include <rte_per_lcore.h>
#include <rte_eal.h>
#include <rte_lcore.h>

#include "eal_private.h"
#include "eal_thread.h"

RTE_DEFINE_PER_LCORE(unsigned, _lcore_id) = LCORE_ID_ANY;
RTE_DEFINE_PER_LCORE(unsigned, _socket_id) = (unsigned)SOCKET_ID_ANY;
RTE_DEFINE_PER_LCORE(rte_cpuset_t, _cpuset);

/*
 * Send a message to a slave lcore identified by slave_id to call a
 * function f with argument arg. Once the execution is done, the
 * remote lcore switch in FINISHED state.
 */
int
rte_eal_remote_launch(int (*f)(void *), void *arg, unsigned slave_id)
{
	int n;
	char c = 0;
	int m2s = lcore_config[slave_id].pipe_master2slave[1];
	int s2m = lcore_config[slave_id].pipe_slave2master[0];

	if (lcore_config[slave_id].state != WAIT)
		return -EBUSY;

	lcore_config[slave_id].f = f;
	lcore_config[slave_id].arg = arg;

	/* send message */
	n = 0;
	while (n == 0 || (n < 0 && errno == EINTR))
		n = write(m2s, &c, 1);
	if (n < 0)
		rte_panic("cannot write on configuration pipe\n");

	/* wait ack */
	do {
		n = read(s2m, &c, 1);
	} while (n < 0 && errno == EINTR);

	if (n <= 0)
		rte_panic("cannot read on configuration pipe\n");

	return 0;
}

/* set affinity for current EAL thread */
static int
eal_thread_set_affinity(void)
{
	unsigned lcore_id = rte_lcore_id();

	/* acquire system unique id  */
	rte_gettid();

	/* update EAL thread core affinity */
	return rte_thread_set_affinity(&lcore_config[lcore_id].cpuset);
}

void eal_thread_init_master(unsigned lcore_id)
{
	/* set the lcore ID in per-lcore memory area */
	RTE_PER_LCORE(_lcore_id) = lcore_id;

	/* set CPU affinity */
	if (eal_thread_set_affinity() < 0)
		rte_panic("cannot set affinity\n");
}

/* main loop of threads */
__attribute__((noreturn)) void *
eal_thread_loop(__attribute__((unused)) void *arg)
{
	char c;
	int n, ret;
	unsigned lcore_id;
	pthread_t thread_id;
	int m2s, s2m;
	char cpuset[RTE_CPU_AFFINITY_STR_LEN];

	thread_id = pthread_self();

	/* retrieve our lcore_id from the configuration structure */
	RTE_LCORE_FOREACH_SLAVE(lcore_id) {
		if (thread_id == lcore_config[lcore_id].thread_id)
			break;
	}
	if (lcore_id == RTE_MAX_LCORE)
		rte_panic("cannot retrieve lcore id\n");

	m2s = lcore_config[lcore_id].pipe_master2slave[0];
	s2m = lcore_config[lcore_id].pipe_slave2master[1];

	/* set the lcore ID in per-lcore memory area */
	RTE_PER_LCORE(_lcore_id) = lcore_id;

	/* set CPU affinity */
	if (eal_thread_set_affinity() < 0)
		rte_panic("cannot set affinity\n");

	ret = eal_thread_dump_affinity(cpuset, RTE_CPU_AFFINITY_STR_LEN);

	RTE_LOG(DEBUG, EAL, "lcore %u is ready (tid=%x;cpuset=[%s%s])\n",
		lcore_id, (int)thread_id, cpuset, ret == 0 ? "" : "...");

	/* read on our pipe to get commands */
	while (1) {
		void *fct_arg;

		/* wait command */
		do {
			n = read(m2s, &c, 1);
		} while (n < 0 && errno == EINTR);

		if (n <= 0)
			rte_panic("cannot read on configuration pipe\n");

		lcore_config[lcore_id].state = RUNNING;

		/* send ack */
		n = 0;
		while (n == 0 || (n < 0 && errno == EINTR))
			n = write(s2m, &c, 1);
		if (n < 0)
			rte_panic("cannot write on configuration pipe\n");

		if (lcore_config[lcore_id].f == NULL)
			rte_panic("NULL function pointer\n");

		/* call the function and store the return value */
		fct_arg = lcore_config[lcore_id].arg;
		ret = lcore_config[lcore_id].f(fct_arg);
		lcore_config[lcore_id].ret = ret;
		rte_wmb();

		/* when a service core returns, it should go directly to WAIT
		 * state, because the application will not lcore_wait() for it.
		 */
		if (lcore_config[lcore_id].core_role == ROLE_SERVICE)
			lcore_config[lcore_id].state = WAIT;
		else
			lcore_config[lcore_id].state = FINISHED;
	}

	/* never reached */
	/* pthread_exit(NULL); */
	/* return NULL; */
}

/* require calling thread tid by gettid() */
int rte_sys_gettid(void)
{
	return (int)syscall(SYS_gettid);
}

int rte_thread_setname(pthread_t id, const char *name)
{
	int ret = ENOSYS;
#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ(2, 12)
	ret = pthread_setname_np(id, name);
#endif
#endif
	RTE_SET_USED(id);
	RTE_SET_USED(name);
	return -ret;
}