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/*-
* 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 <unistd.h>
#include <limits.h>
#include <string.h>
#include <dirent.h>
#include <rte_log.h>
#include <rte_eal.h>
#include <rte_lcore.h>
#include <rte_common.h>
#include <rte_string_fns.h>
#include <rte_debug.h>
#include "eal_private.h"
#include "eal_filesystem.h"
#define SYS_CPU_DIR "/sys/devices/system/cpu/cpu%u"
#define CORE_ID_FILE "topology/core_id"
#define PHYS_PKG_FILE "topology/physical_package_id"
/* Check if a cpu is present by the presence of the cpu information for it */
static int
cpu_detected(unsigned lcore_id)
{
char path[PATH_MAX];
int len = snprintf(path, sizeof(path), SYS_CPU_DIR
"/"CORE_ID_FILE, lcore_id);
if (len <= 0 || (unsigned)len >= sizeof(path))
return 0;
if (access(path, F_OK) != 0)
return 0;
return 1;
}
/* Get CPU socket id (NUMA node) by reading directory
* /sys/devices/system/cpu/cpuX looking for symlink "nodeY"
* which gives the NUMA topology information.
* Note: physical package id != NUMA node, but we use it as a
* fallback for kernels which don't create a nodeY link
*/
static unsigned
cpu_socket_id(unsigned lcore_id)
{
const char node_prefix[] = "node";
const size_t prefix_len = sizeof(node_prefix) - 1;
char path[PATH_MAX];
DIR *d = NULL;
unsigned long id = 0;
struct dirent *e;
char *endptr = NULL;
int len = snprintf(path, sizeof(path),
SYS_CPU_DIR, lcore_id);
if (len <= 0 || (unsigned)len >= sizeof(path))
goto err;
d = opendir(path);
if (!d)
goto err;
while ((e = readdir(d)) != NULL) {
if (strncmp(e->d_name, node_prefix, prefix_len) == 0) {
id = strtoul(e->d_name+prefix_len, &endptr, 0);
break;
}
}
if (endptr == NULL || *endptr!='\0' || endptr == e->d_name+prefix_len) {
RTE_LOG(WARNING, EAL, "Cannot read numa node link "
"for lcore %u - using physical package id instead\n",
lcore_id);
len = snprintf(path, sizeof(path), SYS_CPU_DIR "/%s",
lcore_id, PHYS_PKG_FILE);
if (len <= 0 || (unsigned)len >= sizeof(path))
goto err;
if (eal_parse_sysfs_value(path, &id) != 0)
goto err;
}
closedir(d);
return (unsigned)id;
err:
if (d)
closedir(d);
RTE_LOG(ERR, EAL, "Error getting NUMA socket information from %s "
"for lcore %u - assuming NUMA socket 0\n", SYS_CPU_DIR, lcore_id);
return 0;
}
/* Get the cpu core id value from the /sys/.../cpuX core_id value */
static unsigned
cpu_core_id(unsigned lcore_id)
{
char path[PATH_MAX];
unsigned long id;
int len = snprintf(path, sizeof(path), SYS_CPU_DIR "/%s", lcore_id, CORE_ID_FILE);
if (len <= 0 || (unsigned)len >= sizeof(path))
goto err;
if (eal_parse_sysfs_value(path, &id) != 0)
goto err;
return (unsigned)id;
err:
RTE_LOG(ERR, EAL, "Error reading core id value from %s "
"for lcore %u - assuming core 0\n", SYS_CPU_DIR, lcore_id);
return 0;
}
/*
* Parse /sys/devices/system/cpu to get the number of physical and logical
* processors on the machine. The function will fill the cpu_info
* structure.
*/
int
rte_eal_cpu_init(void)
{
/* pointer to global configuration */
struct rte_config *config = rte_eal_get_configuration();
unsigned lcore_id;
unsigned count = 0;
/*
* Parse the maximum set of logical cores, detect the subset of running
* ones and enable them by default.
*/
for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
lcore_config[lcore_id].detected = cpu_detected(lcore_id);
if (lcore_config[lcore_id].detected == 0) {
config->lcore_role[lcore_id] = ROLE_OFF;
continue;
}
/* By default, each detected core is enabled */
config->lcore_role[lcore_id] = ROLE_RTE;
lcore_config[lcore_id].core_id = cpu_core_id(lcore_id);
lcore_config[lcore_id].socket_id = cpu_socket_id(lcore_id);
if (lcore_config[lcore_id].socket_id >= RTE_MAX_NUMA_NODES)
#ifdef RTE_EAL_ALLOW_INV_SOCKET_ID
lcore_config[lcore_id].socket_id = 0;
#else
rte_panic("Socket ID (%u) is greater than "
"RTE_MAX_NUMA_NODES (%d)\n",
lcore_config[lcore_id].socket_id, RTE_MAX_NUMA_NODES);
#endif
RTE_LOG(DEBUG, EAL, "Detected lcore %u as core %u on socket %u\n",
lcore_id,
lcore_config[lcore_id].core_id,
lcore_config[lcore_id].socket_id);
count ++;
}
/* Set the count of enabled logical cores of the EAL configuration */
config->lcore_count = count;
RTE_LOG(DEBUG, EAL, "Support maximum %u logical core(s) by configuration.\n",
RTE_MAX_LCORE);
RTE_LOG(DEBUG, EAL, "Detected %u lcore(s)\n", config->lcore_count);
return 0;
}
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