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  *  version: DPDK.L.1.2.3-3
  34  */
  35
  36 #include <string.h>
  37 #include <sys/types.h>
  38 #include <dirent.h>
  39 #include <stdint.h>
  40 #include <stdlib.h>
  41 #include <stdio.h>
  42 #include <inttypes.h>
  43 #include <stdarg.h>
  44 #include <errno.h>
  45 #include <sys/queue.h>
  46
  47 #include "rte_memory.h"
  48 #include "rte_memzone.h"
  49 #include "rte_tailq.h"
  50 #include "rte_eal.h"
  51 #include "rte_launch.h"
  52 #include "rte_per_lcore.h"
  53 #include "rte_lcore.h"
  54 #include "rte_debug.h"
  55 #include "rte_log.h"
  56 #include "rte_common.h"
  57 #include "rte_string_fns.h"
  58 #include "eal_internal_cfg.h"
  59 #include "eal_hugepages.h"
  60
  61 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  62
  63 static int32_t
  64 get_num_hugepages(const char *subdir)
  65 {
  66         const char nr_hp_file[] = "nr_hugepages";
  67         char path[BUFSIZ];
  68         unsigned num_pages = 0;
  69
  70         rte_snprintf(path, sizeof(path), "%s/%s/%s",
  71                         sys_dir_path, subdir, nr_hp_file);
  72         FILE *fd = fopen(path, "r");
  73         if (fd == NULL || fscanf(fd, "%u", &num_pages) != 1)
  74                 rte_panic("Error reading file '%s'\n", path);
  75         fclose(fd);
  76
  77         return num_pages;
  78 }
  79
  80 static uint64_t
  81 get_default_hp_size(void)
  82 {
  83         const char proc_meminfo[] = "/proc/meminfo";
  84         const char str_hugepagesz[] = "Hugepagesize:";
  85         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
  86         char buffer[256];
  87         unsigned long long size = 0;
  88
  89         FILE *fd = fopen(proc_meminfo, "r");
  90         if (fd == NULL)
  91                 rte_panic("Cannot open %s\n", proc_meminfo);
  92         while(fgets(buffer, sizeof(buffer), fd)){
  93                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
  94                         size = rte_str_to_size(&buffer[hugepagesz_len]);
  95                         break;
  96                 }
  97         }
  98         fclose(fd);
  99         if (size == 0)
 100                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 101         return size;
 102 }
 103
 104 static const char *
 105 get_hugepage_dir(uint64_t hugepage_sz)
 106 {
 107         enum proc_mount_fieldnames {
 108                 DEVICE = 0,
 109                 MOUNTPT,
 110                 FSTYPE,
 111                 OPTIONS,
 112                 _FIELDNAME_MAX
 113         };
 114         static uint64_t default_size = 0;
 115         const char proc_mounts[] = "/proc/mounts";
 116         const char hugetlbfs_str[] = "hugetlbfs";
 117         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 118         const char pagesize_opt[] = "pagesize=";
 119         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 120         const char split_tok = ' ';
 121         char *splitstr[_FIELDNAME_MAX];
 122         char buf[BUFSIZ];
 123         char *retval = NULL;
 124
 125         FILE *fd = fopen(proc_mounts, "r");
 126         if (fd == NULL)
 127                 rte_panic("Cannot open %s\n", proc_mounts);
 128
 129         if (default_size == 0)
 130                 default_size = get_default_hp_size();
 131
 132         while (fgets(buf, sizeof(buf), fd)){
 133                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 134                                 split_tok) != _FIELDNAME_MAX) {
 135                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 136                         break; /* return NULL */
 137                 }
 138
 139                 /* we have a specified --huge-dir option, only examine that dir */
 140                 if (internal_config.hugepage_dir != NULL &&
 141                                 strcmp(splitstr[MOUNTPT], internal_config.hugepage_dir) != 0)
 142                         continue;
 143
 144                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 145                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 146
 147                         /* if no explicit page size, the default page size is compared */
 148                         if (pagesz_str == NULL){
 149                                 if (hugepage_sz == default_size){
 150                                         retval = strdup(splitstr[MOUNTPT]);
 151                                         break;
 152                                 }
 153                         }
 154                         /* there is an explicit page size, so check it */
 155                         else {
 156                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 157                                 if (pagesz == hugepage_sz) {
 158                                         retval = strdup(splitstr[MOUNTPT]);
 159                                         break;
 160                                 }
 161                         }
 162                 } /* end if strncmp hugetlbfs */
 163         } /* end while fgets */
 164
 165         fclose(fd);
 166         return retval;
 167 }
 168
 169 static inline void
 170 swap_hpi(struct hugepage_info *a, struct hugepage_info *b)
 171 {
 172         char buf[sizeof(*a)];
 173         memcpy(buf, a, sizeof(*a));
 174         memcpy(a, b, sizeof(*a));
 175         memcpy(b, buf, sizeof(*a));
 176 }
 177
 178 int
 179 eal_hugepage_info_init(void)
 180 {
 181         const char dirent_start_text[] = "hugepages-";
 182         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 183         unsigned i, num_sizes = 0;
 184
 185         DIR *dir = opendir(sys_dir_path);
 186         if (dir == NULL)
 187                 rte_panic("Cannot open directory %s to read system hugepage info\n",
 188                                 sys_dir_path);
 189
 190         struct dirent *dirent = readdir(dir);
 191         while(dirent != NULL){
 192                 if (strncmp(dirent->d_name, dirent_start_text, dirent_start_len) == 0){
 193                         struct hugepage_info *hpi = \
 194                                         &internal_config.hugepage_info[num_sizes];
 195                         hpi->hugepage_sz = rte_str_to_size(&dirent->d_name[dirent_start_len]);
 196                         hpi->num_pages = get_num_hugepages(dirent->d_name);
 197                         hpi->hugedir = get_hugepage_dir(hpi->hugepage_sz);
 198                         if (hpi->hugedir == NULL){
 199                                 RTE_LOG(INFO, EAL, "%u hugepages of size %llu reserved, "\
 200                                                 "but no mounted hugetlbfs found for that size\n",
 201                                                 hpi->num_pages,
 202                                                 (unsigned long long)hpi->hugepage_sz);
 203                                 hpi->num_pages = 0;
 204                         } else
 205                                 num_sizes++;
 206                 }
 207                 dirent = readdir(dir);
 208         }
 209         closedir(dir);
 210         internal_config.num_hugepage_sizes = num_sizes;
 211
 212         /* sort the page directory entries by size, largest to smallest */
 213         for (i = 0; i < num_sizes; i++){
 214                 unsigned j;
 215                 for (j = i+1; j < num_sizes; j++)
 216                         if (internal_config.hugepage_info[j-1].hugepage_sz < \
 217                                         internal_config.hugepage_info[j].hugepage_sz)
 218                                 swap_hpi(&internal_config.hugepage_info[j-1],
 219                                                 &internal_config.hugepage_info[j]);
 220         }
 221
 222         /* now we have all info, check we have at least one valid size */
 223         for (i = 0; i < num_sizes; i++)
 224                 if (internal_config.hugepage_info[i].hugedir != NULL &&
 225                                 internal_config.hugepage_info[i].num_pages > 0)
 226                         return 0;
 227         /* no valid hugepage mounts available, return error */
 228         return -1;
 229 }