lib/librte_eal/linuxapp/eal/eal_hugepage_info.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <string.h>
   6 #include <sys/types.h>
   7 #include <sys/file.h>
   8 #include <dirent.h>
   9 #include <fcntl.h>
  10 #include <stdint.h>
  11 #include <stdlib.h>
  12 #include <stdio.h>
  13 #include <fnmatch.h>
  14 #include <inttypes.h>
  15 #include <stdarg.h>
  16 #include <unistd.h>
  17 #include <errno.h>
  18 #include <sys/mman.h>
  19 #include <sys/queue.h>
  20 #include <sys/stat.h>
  21
  22 #include <linux/mman.h> /* for hugetlb-related flags */
  23
  24 #include <rte_memory.h>
  25 #include <rte_eal.h>
  26 #include <rte_launch.h>
  27 #include <rte_per_lcore.h>
  28 #include <rte_lcore.h>
  29 #include <rte_debug.h>
  30 #include <rte_log.h>
  31 #include <rte_common.h>
  32 #include "rte_string_fns.h"
  33 #include "eal_internal_cfg.h"
  34 #include "eal_hugepages.h"
  35 #include "eal_filesystem.h"
  36
  37 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  38 static const char sys_pages_numa_dir_path[] = "/sys/devices/system/node";
  39
  40 /*
  41  * Uses mmap to create a shared memory area for storage of data
  42  * Used in this file to store the hugepage file map on disk
  43  */
  44 static void *
  45 map_shared_memory(const char *filename, const size_t mem_size, int flags)
  46 {
  47         void *retval;
  48         int fd = open(filename, flags, 0666);
  49         if (fd < 0)
  50                 return NULL;
  51         if (ftruncate(fd, mem_size) < 0) {
  52                 close(fd);
  53                 return NULL;
  54         }
  55         retval = mmap(NULL, mem_size, PROT_READ | PROT_WRITE,
  56                         MAP_SHARED, fd, 0);
  57         close(fd);
  58         return retval;
  59 }
  60
  61 static void *
  62 open_shared_memory(const char *filename, const size_t mem_size)
  63 {
  64         return map_shared_memory(filename, mem_size, O_RDWR);
  65 }
  66
  67 static void *
  68 create_shared_memory(const char *filename, const size_t mem_size)
  69 {
  70         return map_shared_memory(filename, mem_size, O_RDWR | O_CREAT);
  71 }
  72
  73 /* this function is only called from eal_hugepage_info_init which itself
  74  * is only called from a primary process */
  75 static uint32_t
  76 get_num_hugepages(const char *subdir)
  77 {
  78         char path[PATH_MAX];
  79         long unsigned resv_pages, num_pages = 0;
  80         const char *nr_hp_file = "free_hugepages";
  81         const char *nr_rsvd_file = "resv_hugepages";
  82
  83         /* first, check how many reserved pages kernel reports */
  84         snprintf(path, sizeof(path), "%s/%s/%s",
  85                         sys_dir_path, subdir, nr_rsvd_file);
  86         if (eal_parse_sysfs_value(path, &resv_pages) < 0)
  87                 return 0;
  88
  89         snprintf(path, sizeof(path), "%s/%s/%s",
  90                         sys_dir_path, subdir, nr_hp_file);
  91         if (eal_parse_sysfs_value(path, &num_pages) < 0)
  92                 return 0;
  93
  94         if (num_pages == 0)
  95                 RTE_LOG(WARNING, EAL, "No free hugepages reported in %s\n",
  96                                 subdir);
  97
  98         /* adjust num_pages */
  99         if (num_pages >= resv_pages)
 100                 num_pages -= resv_pages;
 101         else if (resv_pages)
 102                 num_pages = 0;
 103
 104         /* we want to return a uint32_t and more than this looks suspicious
 105          * anyway ... */
 106         if (num_pages > UINT32_MAX)
 107                 num_pages = UINT32_MAX;
 108
 109         return num_pages;
 110 }
 111
 112 static uint32_t
 113 get_num_hugepages_on_node(const char *subdir, unsigned int socket)
 114 {
 115         char path[PATH_MAX], socketpath[PATH_MAX];
 116         DIR *socketdir;
 117         unsigned long num_pages = 0;
 118         const char *nr_hp_file = "free_hugepages";
 119
 120         snprintf(socketpath, sizeof(socketpath), "%s/node%u/hugepages",
 121                 sys_pages_numa_dir_path, socket);
 122
 123         socketdir = opendir(socketpath);
 124         if (socketdir) {
 125                 /* Keep calm and carry on */
 126                 closedir(socketdir);
 127         } else {
 128                 /* Can't find socket dir, so ignore it */
 129                 return 0;
 130         }
 131
 132         snprintf(path, sizeof(path), "%s/%s/%s",
 133                         socketpath, subdir, nr_hp_file);
 134         if (eal_parse_sysfs_value(path, &num_pages) < 0)
 135                 return 0;
 136
 137         if (num_pages == 0)
 138                 RTE_LOG(WARNING, EAL, "No free hugepages reported in %s\n",
 139                                 subdir);
 140
 141         /*
 142          * we want to return a uint32_t and more than this looks suspicious
 143          * anyway ...
 144          */
 145         if (num_pages > UINT32_MAX)
 146                 num_pages = UINT32_MAX;
 147
 148         return num_pages;
 149 }
 150
 151 static uint64_t
 152 get_default_hp_size(void)
 153 {
 154         const char proc_meminfo[] = "/proc/meminfo";
 155         const char str_hugepagesz[] = "Hugepagesize:";
 156         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
 157         char buffer[256];
 158         unsigned long long size = 0;
 159
 160         FILE *fd = fopen(proc_meminfo, "r");
 161         if (fd == NULL)
 162                 rte_panic("Cannot open %s\n", proc_meminfo);
 163         while(fgets(buffer, sizeof(buffer), fd)){
 164                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
 165                         size = rte_str_to_size(&buffer[hugepagesz_len]);
 166                         break;
 167                 }
 168         }
 169         fclose(fd);
 170         if (size == 0)
 171                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 172         return size;
 173 }
 174
 175 static int
 176 get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
 177 {
 178         enum proc_mount_fieldnames {
 179                 DEVICE = 0,
 180                 MOUNTPT,
 181                 FSTYPE,
 182                 OPTIONS,
 183                 _FIELDNAME_MAX
 184         };
 185         static uint64_t default_size = 0;
 186         const char proc_mounts[] = "/proc/mounts";
 187         const char hugetlbfs_str[] = "hugetlbfs";
 188         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 189         const char pagesize_opt[] = "pagesize=";
 190         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 191         const char split_tok = ' ';
 192         char *splitstr[_FIELDNAME_MAX];
 193         char buf[BUFSIZ];
 194         int retval = -1;
 195
 196         FILE *fd = fopen(proc_mounts, "r");
 197         if (fd == NULL)
 198                 rte_panic("Cannot open %s\n", proc_mounts);
 199
 200         if (default_size == 0)
 201                 default_size = get_default_hp_size();
 202
 203         while (fgets(buf, sizeof(buf), fd)){
 204                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 205                                 split_tok) != _FIELDNAME_MAX) {
 206                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 207                         break; /* return NULL */
 208                 }
 209
 210                 /* we have a specified --huge-dir option, only examine that dir */
 211                 if (internal_config.hugepage_dir != NULL &&
 212                                 strcmp(splitstr[MOUNTPT], internal_config.hugepage_dir) != 0)
 213                         continue;
 214
 215                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 216                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 217
 218                         /* if no explicit page size, the default page size is compared */
 219                         if (pagesz_str == NULL){
 220                                 if (hugepage_sz == default_size){
 221                                         strlcpy(hugedir, splitstr[MOUNTPT], len);
 222                                         retval = 0;
 223                                         break;
 224                                 }
 225                         }
 226                         /* there is an explicit page size, so check it */
 227                         else {
 228                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 229                                 if (pagesz == hugepage_sz) {
 230                                         strlcpy(hugedir, splitstr[MOUNTPT], len);
 231                                         retval = 0;
 232                                         break;
 233                                 }
 234                         }
 235                 } /* end if strncmp hugetlbfs */
 236         } /* end while fgets */
 237
 238         fclose(fd);
 239         return retval;
 240 }
 241
 242 /*
 243  * Clear the hugepage directory of whatever hugepage files
 244  * there are. Checks if the file is locked (i.e.
 245  * if it's in use by another DPDK process).
 246  */
 247 static int
 248 clear_hugedir(const char * hugedir)
 249 {
 250         DIR *dir;
 251         struct dirent *dirent;
 252         int dir_fd, fd, lck_result;
 253         const char filter[] = "*map_*"; /* matches hugepage files */
 254
 255         /* open directory */
 256         dir = opendir(hugedir);
 257         if (!dir) {
 258                 RTE_LOG(ERR, EAL, "Unable to open hugepage directory %s\n",
 259                                 hugedir);
 260                 goto error;
 261         }
 262         dir_fd = dirfd(dir);
 263
 264         dirent = readdir(dir);
 265         if (!dirent) {
 266                 RTE_LOG(ERR, EAL, "Unable to read hugepage directory %s\n",
 267                                 hugedir);
 268                 goto error;
 269         }
 270
 271         while(dirent != NULL){
 272                 /* skip files that don't match the hugepage pattern */
 273                 if (fnmatch(filter, dirent->d_name, 0) > 0) {
 274                         dirent = readdir(dir);
 275                         continue;
 276                 }
 277
 278                 /* try and lock the file */
 279                 fd = openat(dir_fd, dirent->d_name, O_RDONLY);
 280
 281                 /* skip to next file */
 282                 if (fd == -1) {
 283                         dirent = readdir(dir);
 284                         continue;
 285                 }
 286
 287                 /* non-blocking lock */
 288                 lck_result = flock(fd, LOCK_EX | LOCK_NB);
 289
 290                 /* if lock succeeds, remove the file */
 291                 if (lck_result != -1)
 292                         unlinkat(dir_fd, dirent->d_name, 0);
 293                 close (fd);
 294                 dirent = readdir(dir);
 295         }
 296
 297         closedir(dir);
 298         return 0;
 299
 300 error:
 301         if (dir)
 302                 closedir(dir);
 303
 304         RTE_LOG(ERR, EAL, "Error while clearing hugepage dir: %s\n",
 305                 strerror(errno));
 306
 307         return -1;
 308 }
 309
 310 static int
 311 compare_hpi(const void *a, const void *b)
 312 {
 313         const struct hugepage_info *hpi_a = a;
 314         const struct hugepage_info *hpi_b = b;
 315
 316         return hpi_b->hugepage_sz - hpi_a->hugepage_sz;
 317 }
 318
 319 static void
 320 calc_num_pages(struct hugepage_info *hpi, struct dirent *dirent)
 321 {
 322         uint64_t total_pages = 0;
 323         unsigned int i;
 324
 325         /*
 326          * first, try to put all hugepages into relevant sockets, but
 327          * if first attempts fails, fall back to collecting all pages
 328          * in one socket and sorting them later
 329          */
 330         total_pages = 0;
 331         /* we also don't want to do this for legacy init */
 332         if (!internal_config.legacy_mem)
 333                 for (i = 0; i < rte_socket_count(); i++) {
 334                         int socket = rte_socket_id_by_idx(i);
 335                         unsigned int num_pages =
 336                                         get_num_hugepages_on_node(
 337                                                 dirent->d_name, socket);
 338                         hpi->num_pages[socket] = num_pages;
 339                         total_pages += num_pages;
 340                 }
 341         /*
 342          * we failed to sort memory from the get go, so fall
 343          * back to old way
 344          */
 345         if (total_pages == 0) {
 346                 hpi->num_pages[0] = get_num_hugepages(dirent->d_name);
 347
 348 #ifndef RTE_ARCH_64
 349                 /* for 32-bit systems, limit number of hugepages to
 350                  * 1GB per page size */
 351                 hpi->num_pages[0] = RTE_MIN(hpi->num_pages[0],
 352                                 RTE_PGSIZE_1G / hpi->hugepage_sz);
 353 #endif
 354         }
 355 }
 356
 357 static int
 358 hugepage_info_init(void)
 359 {       const char dirent_start_text[] = "hugepages-";
 360         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 361         unsigned int i, num_sizes = 0;
 362         DIR *dir;
 363         struct dirent *dirent;
 364
 365         dir = opendir(sys_dir_path);
 366         if (dir == NULL) {
 367                 RTE_LOG(ERR, EAL,
 368                         "Cannot open directory %s to read system hugepage info\n",
 369                         sys_dir_path);
 370                 return -1;
 371         }
 372
 373         for (dirent = readdir(dir); dirent != NULL; dirent = readdir(dir)) {
 374                 struct hugepage_info *hpi;
 375
 376                 if (strncmp(dirent->d_name, dirent_start_text,
 377                             dirent_start_len) != 0)
 378                         continue;
 379
 380                 if (num_sizes >= MAX_HUGEPAGE_SIZES)
 381                         break;
 382
 383                 hpi = &internal_config.hugepage_info[num_sizes];
 384                 hpi->hugepage_sz =
 385                         rte_str_to_size(&dirent->d_name[dirent_start_len]);
 386
 387                 /* first, check if we have a mountpoint */
 388                 if (get_hugepage_dir(hpi->hugepage_sz,
 389                         hpi->hugedir, sizeof(hpi->hugedir)) < 0) {
 390                         uint32_t num_pages;
 391
 392                         num_pages = get_num_hugepages(dirent->d_name);
 393                         if (num_pages > 0)
 394                                 RTE_LOG(NOTICE, EAL,
 395                                         "%" PRIu32 " hugepages of size "
 396                                         "%" PRIu64 " reserved, but no mounted "
 397                                         "hugetlbfs found for that size\n",
 398                                         num_pages, hpi->hugepage_sz);
 399                         /* if we have kernel support for reserving hugepages
 400                          * through mmap, and we're in in-memory mode, treat this
 401                          * page size as valid. we cannot be in legacy mode at
 402                          * this point because we've checked this earlier in the
 403                          * init process.
 404                          */
 405 #ifdef MAP_HUGE_SHIFT
 406                         if (internal_config.in_memory) {
 407                                 RTE_LOG(DEBUG, EAL, "In-memory mode enabled, "
 408                                         "hugepages of size %" PRIu64 " bytes "
 409                                         "will be allocated anonymously\n",
 410                                         hpi->hugepage_sz);
 411                                 calc_num_pages(hpi, dirent);
 412                                 num_sizes++;
 413                         }
 414 #endif
 415                         continue;
 416                 }
 417
 418                 /* try to obtain a writelock */
 419                 hpi->lock_descriptor = open(hpi->hugedir, O_RDONLY);
 420
 421                 /* if blocking lock failed */
 422                 if (flock(hpi->lock_descriptor, LOCK_EX) == -1) {
 423                         RTE_LOG(CRIT, EAL,
 424                                 "Failed to lock hugepage directory!\n");
 425                         break;
 426                 }
 427                 /* clear out the hugepages dir from unused pages */
 428                 if (clear_hugedir(hpi->hugedir) == -1)
 429                         break;
 430
 431                 calc_num_pages(hpi, dirent);
 432
 433                 num_sizes++;
 434         }
 435         closedir(dir);
 436
 437         /* something went wrong, and we broke from the for loop above */
 438         if (dirent != NULL)
 439                 return -1;
 440
 441         internal_config.num_hugepage_sizes = num_sizes;
 442
 443         /* sort the page directory entries by size, largest to smallest */
 444         qsort(&internal_config.hugepage_info[0], num_sizes,
 445               sizeof(internal_config.hugepage_info[0]), compare_hpi);
 446
 447         /* now we have all info, check we have at least one valid size */
 448         for (i = 0; i < num_sizes; i++) {
 449                 /* pages may no longer all be on socket 0, so check all */
 450                 unsigned int j, num_pages = 0;
 451                 struct hugepage_info *hpi = &internal_config.hugepage_info[i];
 452
 453                 for (j = 0; j < RTE_MAX_NUMA_NODES; j++)
 454                         num_pages += hpi->num_pages[j];
 455                 if (num_pages > 0)
 456                         return 0;
 457         }
 458
 459         /* no valid hugepage mounts available, return error */
 460         return -1;
 461 }
 462
 463 /*
 464  * when we initialize the hugepage info, everything goes
 465  * to socket 0 by default. it will later get sorted by memory
 466  * initialization procedure.
 467  */
 468 int
 469 eal_hugepage_info_init(void)
 470 {
 471         struct hugepage_info *hpi, *tmp_hpi;
 472         unsigned int i;
 473
 474         if (hugepage_info_init() < 0)
 475                 return -1;
 476
 477         /* for no shared files mode, we're done */
 478         if (internal_config.no_shconf)
 479                 return 0;
 480
 481         hpi = &internal_config.hugepage_info[0];
 482
 483         tmp_hpi = create_shared_memory(eal_hugepage_info_path(),
 484                         sizeof(internal_config.hugepage_info));
 485         if (tmp_hpi == NULL) {
 486                 RTE_LOG(ERR, EAL, "Failed to create shared memory!\n");
 487                 return -1;
 488         }
 489
 490         memcpy(tmp_hpi, hpi, sizeof(internal_config.hugepage_info));
 491
 492         /* we've copied file descriptors along with everything else, but they
 493          * will be invalid in secondary process, so overwrite them
 494          */
 495         for (i = 0; i < RTE_DIM(internal_config.hugepage_info); i++) {
 496                 struct hugepage_info *tmp = &tmp_hpi[i];
 497                 tmp->lock_descriptor = -1;
 498         }
 499
 500         if (munmap(tmp_hpi, sizeof(internal_config.hugepage_info)) < 0) {
 501                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 502                 return -1;
 503         }
 504         return 0;
 505 }
 506
 507 int eal_hugepage_info_read(void)
 508 {
 509         struct hugepage_info *hpi = &internal_config.hugepage_info[0];
 510         struct hugepage_info *tmp_hpi;
 511
 512         tmp_hpi = open_shared_memory(eal_hugepage_info_path(),
 513                                   sizeof(internal_config.hugepage_info));
 514         if (tmp_hpi == NULL) {
 515                 RTE_LOG(ERR, EAL, "Failed to open shared memory!\n");
 516                 return -1;
 517         }
 518
 519         memcpy(hpi, tmp_hpi, sizeof(internal_config.hugepage_info));
 520
 521         if (munmap(tmp_hpi, sizeof(internal_config.hugepage_info)) < 0) {
 522                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 523                 return -1;
 524         }
 525         return 0;
 526 }