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41 #include <rte_lcore.h>
42 #include <rte_common.h>
43 #include <rte_string_fns.h>
44 #include <rte_debug.h>
46 #include "eal_private.h"
47 #include "eal_filesystem.h"
48 #include "eal_thread.h"
50 #define SYS_CPU_DIR "/sys/devices/system/cpu/cpu%u"
51 #define CORE_ID_FILE "topology/core_id"
52 #define NUMA_NODE_PATH "/sys/devices/system/node"
54 /* Check if a cpu is present by the presence of the cpu information for it */
56 cpu_detected(unsigned lcore_id)
59 int len = snprintf(path, sizeof(path), SYS_CPU_DIR
60 "/"CORE_ID_FILE, lcore_id);
61 if (len <= 0 || (unsigned)len >= sizeof(path))
63 if (access(path, F_OK) != 0)
70 * Get CPU socket id (NUMA node) for a logical core.
72 * This searches each nodeX directories in /sys for the symlink for the given
73 * lcore_id and returns the numa node where the lcore is found. If lcore is not
74 * found on any numa node, returns zero.
77 eal_cpu_socket_id(unsigned lcore_id)
81 for (socket = 0; socket < RTE_MAX_NUMA_NODES; socket++) {
84 snprintf(path, sizeof(path), "%s/node%u/cpu%u", NUMA_NODE_PATH,
86 if (access(path, F_OK) == 0)
92 /* Get the cpu core id value from the /sys/.../cpuX core_id value */
94 cpu_core_id(unsigned lcore_id)
99 int len = snprintf(path, sizeof(path), SYS_CPU_DIR "/%s", lcore_id, CORE_ID_FILE);
100 if (len <= 0 || (unsigned)len >= sizeof(path))
102 if (eal_parse_sysfs_value(path, &id) != 0)
107 RTE_LOG(ERR, EAL, "Error reading core id value from %s "
108 "for lcore %u - assuming core 0\n", SYS_CPU_DIR, lcore_id);
113 * Parse /sys/devices/system/cpu to get the number of physical and logical
114 * processors on the machine. The function will fill the cpu_info
118 rte_eal_cpu_init(void)
120 /* pointer to global configuration */
121 struct rte_config *config = rte_eal_get_configuration();
126 * Parse the maximum set of logical cores, detect the subset of running
127 * ones and enable them by default.
129 for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
130 /* init cpuset for per lcore config */
131 CPU_ZERO(&lcore_config[lcore_id].cpuset);
133 /* in 1:1 mapping, record related cpu detected state */
134 lcore_config[lcore_id].detected = cpu_detected(lcore_id);
135 if (lcore_config[lcore_id].detected == 0) {
136 config->lcore_role[lcore_id] = ROLE_OFF;
140 /* By default, lcore 1:1 map to cpu id */
141 CPU_SET(lcore_id, &lcore_config[lcore_id].cpuset);
143 /* By default, each detected core is enabled */
144 config->lcore_role[lcore_id] = ROLE_RTE;
145 lcore_config[lcore_id].core_id = cpu_core_id(lcore_id);
146 lcore_config[lcore_id].socket_id = eal_cpu_socket_id(lcore_id);
147 if (lcore_config[lcore_id].socket_id >= RTE_MAX_NUMA_NODES)
148 #ifdef RTE_EAL_ALLOW_INV_SOCKET_ID
149 lcore_config[lcore_id].socket_id = 0;
151 rte_panic("Socket ID (%u) is greater than "
152 "RTE_MAX_NUMA_NODES (%d)\n",
153 lcore_config[lcore_id].socket_id, RTE_MAX_NUMA_NODES);
155 RTE_LOG(DEBUG, EAL, "Detected lcore %u as core %u on socket %u\n",
157 lcore_config[lcore_id].core_id,
158 lcore_config[lcore_id].socket_id);
161 /* Set the count of enabled logical cores of the EAL configuration */
162 config->lcore_count = count;
163 RTE_LOG(DEBUG, EAL, "Support maximum %u logical core(s) by configuration.\n",
165 RTE_LOG(DEBUG, EAL, "Detected %u lcore(s)\n", config->lcore_count);