lib/librte_eal/linuxapp/eal/eal_hugepage_info.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 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 #include <string.h>
  35 #include <sys/types.h>
  36 #include <sys/file.h>
  37 #include <dirent.h>
  38 #include <stdint.h>
  39 #include <stdlib.h>
  40 #include <stdio.h>
  41 #include <fnmatch.h>
  42 #include <inttypes.h>
  43 #include <stdarg.h>
  44 #include <unistd.h>
  45 #include <errno.h>
  46 #include <sys/queue.h>
  47
  48 #include <rte_memory.h>
  49 #include <rte_memzone.h>
  50 #include <rte_tailq.h>
  51 #include <rte_eal.h>
  52 #include <rte_launch.h>
  53 #include <rte_per_lcore.h>
  54 #include <rte_lcore.h>
  55 #include <rte_debug.h>
  56 #include <rte_log.h>
  57 #include <rte_common.h>
  58 #include "rte_string_fns.h"
  59 #include "eal_internal_cfg.h"
  60 #include "eal_hugepages.h"
  61 #include "eal_filesystem.h"
  62
  63 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  64
  65 static int32_t
  66 get_num_hugepages(const char *subdir)
  67 {
  68         char path[PATH_MAX];
  69         long unsigned resv_pages, num_pages = 0;
  70         const char *nr_hp_file;
  71         const char *nr_rsvd_file = "resv_hugepages";
  72
  73         /* first, check how many reserved pages kernel reports */
  74         snprintf(path, sizeof(path), "%s/%s/%s",
  75                         sys_dir_path, subdir, nr_rsvd_file);
  76
  77         if (eal_parse_sysfs_value(path, &resv_pages) < 0)
  78                 return 0;
  79
  80         /* if secondary process, just look at the number of hugepages,
  81          * otherwise look at number of free hugepages */
  82         if (internal_config.process_type == RTE_PROC_SECONDARY)
  83                 nr_hp_file = "nr_hugepages";
  84         else
  85                 nr_hp_file = "free_hugepages";
  86
  87         snprintf(path, sizeof(path), "%s/%s/%s",
  88                         sys_dir_path, subdir, nr_hp_file);
  89
  90         if (eal_parse_sysfs_value(path, &num_pages) < 0)
  91                 return 0;
  92
  93         if (num_pages == 0)
  94                 RTE_LOG(WARNING, EAL, "No free hugepages reported in %s\n",
  95                                 subdir);
  96
  97         /* adjust num_pages in case of primary process */
  98         if (num_pages > 0 && internal_config.process_type == RTE_PROC_PRIMARY)
  99                 num_pages -= resv_pages;
 100
 101         return (int32_t)num_pages;
 102 }
 103
 104 static uint64_t
 105 get_default_hp_size(void)
 106 {
 107         const char proc_meminfo[] = "/proc/meminfo";
 108         const char str_hugepagesz[] = "Hugepagesize:";
 109         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
 110         char buffer[256];
 111         unsigned long long size = 0;
 112
 113         FILE *fd = fopen(proc_meminfo, "r");
 114         if (fd == NULL)
 115                 rte_panic("Cannot open %s\n", proc_meminfo);
 116         while(fgets(buffer, sizeof(buffer), fd)){
 117                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
 118                         size = rte_str_to_size(&buffer[hugepagesz_len]);
 119                         break;
 120                 }
 121         }
 122         fclose(fd);
 123         if (size == 0)
 124                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 125         return size;
 126 }
 127
 128 static const char *
 129 get_hugepage_dir(uint64_t hugepage_sz)
 130 {
 131         enum proc_mount_fieldnames {
 132                 DEVICE = 0,
 133                 MOUNTPT,
 134                 FSTYPE,
 135                 OPTIONS,
 136                 _FIELDNAME_MAX
 137         };
 138         static uint64_t default_size = 0;
 139         const char proc_mounts[] = "/proc/mounts";
 140         const char hugetlbfs_str[] = "hugetlbfs";
 141         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 142         const char pagesize_opt[] = "pagesize=";
 143         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 144         const char split_tok = ' ';
 145         char *splitstr[_FIELDNAME_MAX];
 146         char buf[BUFSIZ];
 147         char *retval = NULL;
 148
 149         FILE *fd = fopen(proc_mounts, "r");
 150         if (fd == NULL)
 151                 rte_panic("Cannot open %s\n", proc_mounts);
 152
 153         if (default_size == 0)
 154                 default_size = get_default_hp_size();
 155
 156         while (fgets(buf, sizeof(buf), fd)){
 157                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 158                                 split_tok) != _FIELDNAME_MAX) {
 159                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 160                         break; /* return NULL */
 161                 }
 162
 163                 /* we have a specified --huge-dir option, only examine that dir */
 164                 if (internal_config.hugepage_dir != NULL &&
 165                                 strcmp(splitstr[MOUNTPT], internal_config.hugepage_dir) != 0)
 166                         continue;
 167
 168                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 169                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 170
 171                         /* if no explicit page size, the default page size is compared */
 172                         if (pagesz_str == NULL){
 173                                 if (hugepage_sz == default_size){
 174                                         retval = strdup(splitstr[MOUNTPT]);
 175                                         break;
 176                                 }
 177                         }
 178                         /* there is an explicit page size, so check it */
 179                         else {
 180                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 181                                 if (pagesz == hugepage_sz) {
 182                                         retval = strdup(splitstr[MOUNTPT]);
 183                                         break;
 184                                 }
 185                         }
 186                 } /* end if strncmp hugetlbfs */
 187         } /* end while fgets */
 188
 189         fclose(fd);
 190         return retval;
 191 }
 192
 193 static inline void
 194 swap_hpi(struct hugepage_info *a, struct hugepage_info *b)
 195 {
 196         char buf[sizeof(*a)];
 197         memcpy(buf, a, sizeof(buf));
 198         memcpy(a, b, sizeof(buf));
 199         memcpy(b, buf, sizeof(buf));
 200 }
 201
 202 /*
 203  * Clear the hugepage directory of whatever hugepage files
 204  * there are. Checks if the file is locked (i.e.
 205  * if it's in use by another DPDK process).
 206  */
 207 static int
 208 clear_hugedir(const char * hugedir)
 209 {
 210         DIR *dir;
 211         struct dirent *dirent;
 212         int dir_fd, fd, lck_result;
 213         const char filter[] = "*map_*"; /* matches hugepage files */
 214
 215         /* open directory */
 216         dir = opendir(hugedir);
 217         if (!dir) {
 218                 RTE_LOG(INFO, EAL, "Unable to open hugepage directory %s\n",
 219                                 hugedir);
 220                 goto error;
 221         }
 222         dir_fd = dirfd(dir);
 223
 224         dirent = readdir(dir);
 225         if (!dirent) {
 226                 RTE_LOG(INFO, EAL, "Unable to read hugepage directory %s\n",
 227                                 hugedir);
 228                 goto error;
 229         }
 230
 231         while(dirent != NULL){
 232                 /* skip files that don't match the hugepage pattern */
 233                 if (fnmatch(filter, dirent->d_name, 0) > 0) {
 234                         dirent = readdir(dir);
 235                         continue;
 236                 }
 237
 238                 /* try and lock the file */
 239                 fd = openat(dir_fd, dirent->d_name, O_RDONLY);
 240
 241                 /* skip to next file */
 242                 if (fd == -1) {
 243                         dirent = readdir(dir);
 244                         continue;
 245                 }
 246
 247                 /* non-blocking lock */
 248                 lck_result = flock(fd, LOCK_EX | LOCK_NB);
 249
 250                 /* if lock succeeds, unlock and remove the file */
 251                 if (lck_result != -1) {
 252                         flock(fd, LOCK_UN);
 253                         unlinkat(dir_fd, dirent->d_name, 0);
 254                 }
 255                 close (fd);
 256                 dirent = readdir(dir);
 257         }
 258
 259         closedir(dir);
 260         return 0;
 261
 262 error:
 263         if (dir)
 264                 closedir(dir);
 265
 266         RTE_LOG(INFO, EAL, "Error while clearing hugepage dir: %s\n",
 267                 strerror(errno));
 268
 269         return -1;
 270 }
 271
 272 /*
 273  * when we initialize the hugepage info, everything goes
 274  * to socket 0 by default. it will later get sorted by memory
 275  * initialization procedure.
 276  */
 277 int
 278 eal_hugepage_info_init(void)
 279 {
 280         const char dirent_start_text[] = "hugepages-";
 281         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 282         unsigned i, num_sizes = 0;
 283
 284         DIR *dir = opendir(sys_dir_path);
 285         if (dir == NULL)
 286                 rte_panic("Cannot open directory %s to read system hugepage info\n",
 287                                 sys_dir_path);
 288
 289         struct dirent *dirent = readdir(dir);
 290         while(dirent != NULL){
 291                 if (strncmp(dirent->d_name, dirent_start_text, dirent_start_len) == 0){
 292                         struct hugepage_info *hpi = \
 293                                         &internal_config.hugepage_info[num_sizes];
 294                         hpi->hugepage_sz = rte_str_to_size(&dirent->d_name[dirent_start_len]);
 295                         hpi->hugedir = get_hugepage_dir(hpi->hugepage_sz);
 296
 297                         /* first, check if we have a mountpoint */
 298                         if (hpi->hugedir == NULL){
 299                                 int32_t num_pages;
 300                                 if ((num_pages = get_num_hugepages(dirent->d_name)) > 0)
 301                                         RTE_LOG(INFO, EAL, "%u hugepages of size %llu reserved, "\
 302                                                         "but no mounted hugetlbfs found for that size\n",
 303                                                         (unsigned)num_pages,
 304                                                         (unsigned long long)hpi->hugepage_sz);
 305                         } else {
 306                                 /* try to obtain a writelock */
 307                                 hpi->lock_descriptor = open(hpi->hugedir, O_RDONLY);
 308
 309                                 /* if blocking lock failed */
 310                                 if (flock(hpi->lock_descriptor, LOCK_EX) == -1) {
 311                                         RTE_LOG(CRIT, EAL, "Failed to lock hugepage directory!\n");
 312                                         closedir(dir);
 313                                         return -1;
 314                                 }
 315                                 /* clear out the hugepages dir from unused pages */
 316                                 if (clear_hugedir(hpi->hugedir) == -1) {
 317                                         closedir(dir);
 318                                         return -1;
 319                                 }
 320
 321                                 /* for now, put all pages into socket 0,
 322                                  * later they will be sorted */
 323                                 hpi->num_pages[0] = get_num_hugepages(dirent->d_name);
 324
 325 #ifndef RTE_ARCH_64
 326                                 /* for 32-bit systems, limit number of hugepages to 1GB per page size */
 327                                 hpi->num_pages[0] = RTE_MIN(hpi->num_pages[0],
 328                                                 RTE_PGSIZE_1G / hpi->hugepage_sz);
 329 #endif
 330
 331                                 num_sizes++;
 332                         }
 333                 }
 334                 dirent = readdir(dir);
 335         }
 336         closedir(dir);
 337         internal_config.num_hugepage_sizes = num_sizes;
 338
 339         /* sort the page directory entries by size, largest to smallest */
 340         for (i = 0; i < num_sizes; i++){
 341                 unsigned j;
 342                 for (j = i+1; j < num_sizes; j++)
 343                         if (internal_config.hugepage_info[j-1].hugepage_sz < \
 344                                         internal_config.hugepage_info[j].hugepage_sz)
 345                                 swap_hpi(&internal_config.hugepage_info[j-1],
 346                                                 &internal_config.hugepage_info[j]);
 347         }
 348
 349         /* now we have all info, check we have at least one valid size */
 350         for (i = 0; i < num_sizes; i++)
 351                 if (internal_config.hugepage_info[i].hugedir != NULL &&
 352                                 internal_config.hugepage_info[i].num_pages[0] > 0)
 353                         return 0;
 354
 355         /* no valid hugepage mounts available, return error */
 356         return -1;
 357 }