lib/librte_eal/linuxapp/eal/eal_hugepage_info.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2013 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 <sys/file.h>
  38 #include <dirent.h>
  39 #include <stdint.h>
  40 #include <stdlib.h>
  41 #include <stdio.h>
  42 #include <fnmatch.h>
  43 #include <inttypes.h>
  44 #include <stdarg.h>
  45 #include <unistd.h>
  46 #include <errno.h>
  47 #include <sys/queue.h>
  48
  49 #include <rte_memory.h>
  50 #include <rte_memzone.h>
  51 #include <rte_tailq.h>
  52 #include <rte_eal.h>
  53 #include <rte_launch.h>
  54 #include <rte_per_lcore.h>
  55 #include <rte_lcore.h>
  56 #include <rte_debug.h>
  57 #include <rte_log.h>
  58 #include <rte_common.h>
  59 #include "rte_string_fns.h"
  60 #include "eal_internal_cfg.h"
  61 #include "eal_hugepages.h"
  62 #include "eal_filesystem.h"
  63
  64 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  65
  66 static int32_t
  67 get_num_hugepages(const char *subdir)
  68 {
  69         char path[PATH_MAX];
  70         long unsigned num_pages = 0;
  71         const char *nr_hp_file;
  72
  73         /* if secondary process, just look at the number of hugepages,
  74          * otherwise look at number of free hugepages */
  75         if (internal_config.process_type == RTE_PROC_SECONDARY)
  76                 nr_hp_file = "nr_hugepages";
  77         else
  78                 nr_hp_file = "free_hugepages";
  79
  80         rte_snprintf(path, sizeof(path), "%s/%s/%s",
  81                         sys_dir_path, subdir, nr_hp_file);
  82
  83         if (eal_parse_sysfs_value(path, &num_pages) < 0)
  84                 return 0;
  85
  86         if (num_pages == 0)
  87                 RTE_LOG(WARNING, EAL, "No free hugepages reported in %s\n",
  88                                 subdir);
  89
  90         return (int32_t)num_pages;
  91 }
  92
  93 static uint64_t
  94 get_default_hp_size(void)
  95 {
  96         const char proc_meminfo[] = "/proc/meminfo";
  97         const char str_hugepagesz[] = "Hugepagesize:";
  98         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
  99         char buffer[256];
 100         unsigned long long size = 0;
 101
 102         FILE *fd = fopen(proc_meminfo, "r");
 103         if (fd == NULL)
 104                 rte_panic("Cannot open %s\n", proc_meminfo);
 105         while(fgets(buffer, sizeof(buffer), fd)){
 106                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
 107                         size = rte_str_to_size(&buffer[hugepagesz_len]);
 108                         break;
 109                 }
 110         }
 111         fclose(fd);
 112         if (size == 0)
 113                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 114         return size;
 115 }
 116
 117 static const char *
 118 get_hugepage_dir(uint64_t hugepage_sz)
 119 {
 120         enum proc_mount_fieldnames {
 121                 DEVICE = 0,
 122                 MOUNTPT,
 123                 FSTYPE,
 124                 OPTIONS,
 125                 _FIELDNAME_MAX
 126         };
 127         static uint64_t default_size = 0;
 128         const char proc_mounts[] = "/proc/mounts";
 129         const char hugetlbfs_str[] = "hugetlbfs";
 130         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 131         const char pagesize_opt[] = "pagesize=";
 132         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 133         const char split_tok = ' ';
 134         char *splitstr[_FIELDNAME_MAX];
 135         char buf[BUFSIZ];
 136         char *retval = NULL;
 137
 138         FILE *fd = fopen(proc_mounts, "r");
 139         if (fd == NULL)
 140                 rte_panic("Cannot open %s\n", proc_mounts);
 141
 142         if (default_size == 0)
 143                 default_size = get_default_hp_size();
 144
 145         while (fgets(buf, sizeof(buf), fd)){
 146                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 147                                 split_tok) != _FIELDNAME_MAX) {
 148                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 149                         break; /* return NULL */
 150                 }
 151
 152                 /* we have a specified --huge-dir option, only examine that dir */
 153                 if (internal_config.hugepage_dir != NULL &&
 154                                 strcmp(splitstr[MOUNTPT], internal_config.hugepage_dir) != 0)
 155                         continue;
 156
 157                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 158                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 159
 160                         /* if no explicit page size, the default page size is compared */
 161                         if (pagesz_str == NULL){
 162                                 if (hugepage_sz == default_size){
 163                                         retval = strdup(splitstr[MOUNTPT]);
 164                                         break;
 165                                 }
 166                         }
 167                         /* there is an explicit page size, so check it */
 168                         else {
 169                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 170                                 if (pagesz == hugepage_sz) {
 171                                         retval = strdup(splitstr[MOUNTPT]);
 172                                         break;
 173                                 }
 174                         }
 175                 } /* end if strncmp hugetlbfs */
 176         } /* end while fgets */
 177
 178         fclose(fd);
 179         return retval;
 180 }
 181
 182 static inline void
 183 swap_hpi(struct hugepage_info *a, struct hugepage_info *b)
 184 {
 185         char buf[sizeof(*a)];
 186         memcpy(buf, a, sizeof(buf));
 187         memcpy(a, b, sizeof(buf));
 188         memcpy(b, buf, sizeof(buf));
 189 }
 190
 191 /*
 192  * Clear the hugepage directory of whatever hugepage files
 193  * there are. Checks if the file is locked (i.e.
 194  * if it's in use by another DPDK process).
 195  */
 196 static int
 197 clear_hugedir(const char * hugedir)
 198 {
 199         DIR *dir;
 200         struct dirent *dirent;
 201         int dir_fd, fd, lck_result;
 202         const char filter[] = "*map_*"; /* matches hugepage files */
 203
 204         /* open directory */
 205         dir = opendir(hugedir);
 206         if (!dir) {
 207                 RTE_LOG(INFO, EAL, "Unable to open hugepage directory %s\n",
 208                                 hugedir);
 209                 goto error;
 210         }
 211         dir_fd = dirfd(dir);
 212
 213         dirent = readdir(dir);
 214         if (!dirent) {
 215                 RTE_LOG(INFO, EAL, "Unable to read hugepage directory %s\n",
 216                                 hugedir);
 217                 goto error;
 218         }
 219
 220         while(dirent != NULL){
 221                 /* skip files that don't match the hugepage pattern */
 222                 if (fnmatch(filter, dirent->d_name, 0) > 0) {
 223                         dirent = readdir(dir);
 224                         continue;
 225                 }
 226
 227                 /* try and lock the file */
 228                 fd = openat(dir_fd, dirent->d_name, O_RDONLY);
 229
 230                 /* skip to next file */
 231                 if (fd == -1) {
 232                         dirent = readdir(dir);
 233                         continue;
 234                 }
 235
 236                 /* non-blocking lock */
 237                 lck_result = flock(fd, LOCK_EX | LOCK_NB);
 238
 239                 /* if lock succeeds, unlock and remove the file */
 240                 if (lck_result != -1) {
 241                         flock(fd, LOCK_UN);
 242                         unlinkat(dir_fd, dirent->d_name, 0);
 243                 }
 244                 close (fd);
 245                 dirent = readdir(dir);
 246         }
 247
 248         closedir(dir);
 249         return 0;
 250
 251 error:
 252         if (dir)
 253                 closedir(dir);
 254
 255         RTE_LOG(INFO, EAL, "Error while clearing hugepage dir: %s\n",
 256                 strerror(errno));
 257
 258         return -1;
 259 }
 260
 261 /*
 262  * when we initialize the hugepage info, everything goes
 263  * to socket 0 by default. it will later get sorted by memory
 264  * initialization procedure.
 265  */
 266 int
 267 eal_hugepage_info_init(void)
 268 {
 269         const char dirent_start_text[] = "hugepages-";
 270         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 271         unsigned i, num_sizes = 0;
 272
 273         DIR *dir = opendir(sys_dir_path);
 274         if (dir == NULL)
 275                 rte_panic("Cannot open directory %s to read system hugepage info\n",
 276                                 sys_dir_path);
 277
 278         struct dirent *dirent = readdir(dir);
 279         while(dirent != NULL){
 280                 if (strncmp(dirent->d_name, dirent_start_text, dirent_start_len) == 0){
 281                         struct hugepage_info *hpi = \
 282                                         &internal_config.hugepage_info[num_sizes];
 283                         hpi->hugepage_sz = rte_str_to_size(&dirent->d_name[dirent_start_len]);
 284                         hpi->hugedir = get_hugepage_dir(hpi->hugepage_sz);
 285
 286                         /* first, check if we have a mountpoint */
 287                         if (hpi->hugedir == NULL){
 288                                 int32_t num_pages;
 289                                 if ((num_pages = get_num_hugepages(dirent->d_name)) > 0)
 290                                         RTE_LOG(INFO, EAL, "%u hugepages of size %llu reserved, "\
 291                                                         "but no mounted hugetlbfs found for that size\n",
 292                                                         (unsigned)num_pages,
 293                                                         (unsigned long long)hpi->hugepage_sz);
 294                         } else {
 295                                 /* try to obtain a writelock */
 296                                 hpi->lock_descriptor = open(hpi->hugedir, O_RDONLY);
 297
 298                                 /* if blocking lock failed */
 299                                 if (flock(hpi->lock_descriptor, LOCK_EX) == -1) {
 300                                         RTE_LOG(CRIT, EAL, "Failed to lock hugepage directory!\n");
 301                                         return -1;
 302                                 }
 303                                 /* clear out the hugepages dir from unused pages */
 304                                 if (clear_hugedir(hpi->hugedir) == -1)
 305                                         return -1;
 306
 307                                 /* for now, put all pages into socket 0,
 308                                  * later they will be sorted */
 309                                 hpi->num_pages[0] = get_num_hugepages(dirent->d_name);
 310
 311 #ifndef RTE_ARCH_X86_64
 312                                 /* for 32-bit systems, limit number of hugepages to 1GB per page size */
 313                                 hpi->num_pages[0] = RTE_MIN(hpi->num_pages[0],
 314                                                 RTE_PGSIZE_1G / hpi->hugepage_sz);
 315 #endif
 316
 317                                 num_sizes++;
 318                         }
 319                 }
 320                 dirent = readdir(dir);
 321         }
 322         closedir(dir);
 323         internal_config.num_hugepage_sizes = num_sizes;
 324
 325         /* sort the page directory entries by size, largest to smallest */
 326         for (i = 0; i < num_sizes; i++){
 327                 unsigned j;
 328                 for (j = i+1; j < num_sizes; j++)
 329                         if (internal_config.hugepage_info[j-1].hugepage_sz < \
 330                                         internal_config.hugepage_info[j].hugepage_sz)
 331                                 swap_hpi(&internal_config.hugepage_info[j-1],
 332                                                 &internal_config.hugepage_info[j]);
 333         }
 334
 335         /* now we have all info, check we have at least one valid size */
 336         for (i = 0; i < num_sizes; i++)
 337                 if (internal_config.hugepage_info[i].hugedir != NULL &&
 338                                 internal_config.hugepage_info[i].num_pages[0] > 0)
 339                         return 0;
 340
 341         /* no valid hugepage mounts available, return error */
 342         return -1;
 343 }