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