lib/librte_eal/linuxapp/eal/eal_hugepage_info.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2012 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
  35 #include <string.h>
  36 #include <sys/types.h>
  37 #include <dirent.h>
  38 #include <stdint.h>
  39 #include <stdlib.h>
  40 #include <stdio.h>
  41 #include <inttypes.h>
  42 #include <stdarg.h>
  43 #include <errno.h>
  44 #include <sys/queue.h>
  45
  46 #include "rte_memory.h"
  47 #include "rte_memzone.h"
  48 #include "rte_tailq.h"
  49 #include "rte_eal.h"
  50 #include "rte_launch.h"
  51 #include "rte_per_lcore.h"
  52 #include "rte_lcore.h"
  53 #include "rte_debug.h"
  54 #include "rte_log.h"
  55 #include "rte_common.h"
  56 #include "rte_string_fns.h"
  57 #include "eal_internal_cfg.h"
  58 #include "eal_hugepages.h"
  59
  60 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  61
  62 static int32_t
  63 get_num_hugepages(const char *subdir)
  64 {
  65         const char nr_hp_file[] = "nr_hugepages";
  66         char path[BUFSIZ];
  67         unsigned num_pages = 0;
  68
  69         rte_snprintf(path, sizeof(path), "%s/%s/%s",
  70                         sys_dir_path, subdir, nr_hp_file);
  71         FILE *fd = fopen(path, "r");
  72         if (fd == NULL || fscanf(fd, "%u", &num_pages) != 1)
  73                 rte_panic("Error reading file '%s'\n", path);
  74         fclose(fd);
  75
  76         return num_pages;
  77 }
  78
  79 static uint64_t
  80 get_default_hp_size(void)
  81 {
  82         const char proc_meminfo[] = "/proc/meminfo";
  83         const char str_hugepagesz[] = "Hugepagesize:";
  84         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
  85         char buffer[256];
  86         unsigned long long size = 0;
  87
  88         FILE *fd = fopen(proc_meminfo, "r");
  89         if (fd == NULL)
  90                 rte_panic("Cannot open %s\n", proc_meminfo);
  91         while(fgets(buffer, sizeof(buffer), fd)){
  92                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
  93                         size = rte_str_to_size(&buffer[hugepagesz_len]);
  94                         break;
  95                 }
  96         }
  97         fclose(fd);
  98         if (size == 0)
  99                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 100         return size;
 101 }
 102
 103 static const char *
 104 get_hugepage_dir(uint64_t hugepage_sz)
 105 {
 106         enum proc_mount_fieldnames {
 107                 DEVICE = 0,
 108                 MOUNTPT,
 109                 FSTYPE,
 110                 OPTIONS,
 111                 _FIELDNAME_MAX
 112         };
 113         static uint64_t default_size = 0;
 114         const char proc_mounts[] = "/proc/mounts";
 115         const char hugetlbfs_str[] = "hugetlbfs";
 116         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 117         const char pagesize_opt[] = "pagesize=";
 118         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 119         const char split_tok = ' ';
 120         char *splitstr[_FIELDNAME_MAX];
 121         char buf[BUFSIZ];
 122         char *retval = NULL;
 123
 124         FILE *fd = fopen(proc_mounts, "r");
 125         if (fd == NULL)
 126                 rte_panic("Cannot open %s\n", proc_mounts);
 127
 128         if (default_size == 0)
 129                 default_size = get_default_hp_size();
 130
 131         while (fgets(buf, sizeof(buf), fd)){
 132                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 133                                 split_tok) != _FIELDNAME_MAX) {
 134                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 135                         break; /* return NULL */
 136                 }
 137
 138                 /* we have a specified --huge-dir option, only examine that dir */
 139                 if (internal_config.hugepage_dir != NULL &&
 140                                 strcmp(splitstr[MOUNTPT], internal_config.hugepage_dir) != 0)
 141                         continue;
 142
 143                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 144                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 145
 146                         /* if no explicit page size, the default page size is compared */
 147                         if (pagesz_str == NULL){
 148                                 if (hugepage_sz == default_size){
 149                                         retval = strdup(splitstr[MOUNTPT]);
 150                                         break;
 151                                 }
 152                         }
 153                         /* there is an explicit page size, so check it */
 154                         else {
 155                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 156                                 if (pagesz == hugepage_sz) {
 157                                         retval = strdup(splitstr[MOUNTPT]);
 158                                         break;
 159                                 }
 160                         }
 161                 } /* end if strncmp hugetlbfs */
 162         } /* end while fgets */
 163
 164         fclose(fd);
 165         return retval;
 166 }
 167
 168 static inline void
 169 swap_hpi(struct hugepage_info *a, struct hugepage_info *b)
 170 {
 171         char buf[sizeof(*a)];
 172         memcpy(buf, a, sizeof(*a));
 173         memcpy(a, b, sizeof(*a));
 174         memcpy(b, buf, sizeof(*a));
 175 }
 176
 177 int
 178 eal_hugepage_info_init(void)
 179 {
 180         const char dirent_start_text[] = "hugepages-";
 181         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 182         unsigned i, num_sizes = 0;
 183
 184         DIR *dir = opendir(sys_dir_path);
 185         if (dir == NULL)
 186                 rte_panic("Cannot open directory %s to read system hugepage info\n",
 187                                 sys_dir_path);
 188
 189         struct dirent *dirent = readdir(dir);
 190         while(dirent != NULL){
 191                 if (strncmp(dirent->d_name, dirent_start_text, dirent_start_len) == 0){
 192                         struct hugepage_info *hpi = \
 193                                         &internal_config.hugepage_info[num_sizes];
 194                         hpi->hugepage_sz = rte_str_to_size(&dirent->d_name[dirent_start_len]);
 195                         hpi->num_pages = get_num_hugepages(dirent->d_name);
 196                         hpi->hugedir = get_hugepage_dir(hpi->hugepage_sz);
 197                         if (hpi->hugedir == NULL){
 198                                 RTE_LOG(INFO, EAL, "%u hugepages of size %llu reserved, "\
 199                                                 "but no mounted hugetlbfs found for that size\n",
 200                                                 hpi->num_pages,
 201                                                 (unsigned long long)hpi->hugepage_sz);
 202                                 hpi->num_pages = 0;
 203                         } else
 204                                 num_sizes++;
 205                 }
 206                 dirent = readdir(dir);
 207         }
 208         closedir(dir);
 209         internal_config.num_hugepage_sizes = num_sizes;
 210
 211         /* sort the page directory entries by size, largest to smallest */
 212         for (i = 0; i < num_sizes; i++){
 213                 unsigned j;
 214                 for (j = i+1; j < num_sizes; j++)
 215                         if (internal_config.hugepage_info[j-1].hugepage_sz < \
 216                                         internal_config.hugepage_info[j].hugepage_sz)
 217                                 swap_hpi(&internal_config.hugepage_info[j-1],
 218                                                 &internal_config.hugepage_info[j]);
 219         }
 220
 221         /* now we have all info, check we have at least one valid size */
 222         for (i = 0; i < num_sizes; i++)
 223                 if (internal_config.hugepage_info[i].hugedir != NULL &&
 224                                 internal_config.hugepage_info[i].num_pages > 0)
 225                         return 0;
 226         /* no valid hugepage mounts available, return error */
 227         return -1;
 228 }