lib/eal/linux/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
  34 #include "eal_private.h"
  35 #include "eal_internal_cfg.h"
  36 #include "eal_hugepages.h"
  37 #include "eal_filesystem.h"
  38
  39 static const char sys_dir_path[] = "/sys/kernel/mm/hugepages";
  40 static const char sys_pages_numa_dir_path[] = "/sys/devices/system/node";
  41
  42 /*
  43  * Uses mmap to create a shared memory area for storage of data
  44  * Used in this file to store the hugepage file map on disk
  45  */
  46 static void *
  47 map_shared_memory(const char *filename, const size_t mem_size, int flags)
  48 {
  49         void *retval;
  50         int fd = open(filename, flags, 0600);
  51         if (fd < 0)
  52                 return NULL;
  53         if (ftruncate(fd, mem_size) < 0) {
  54                 close(fd);
  55                 return NULL;
  56         }
  57         retval = mmap(NULL, mem_size, PROT_READ | PROT_WRITE,
  58                         MAP_SHARED, fd, 0);
  59         close(fd);
  60         return retval;
  61 }
  62
  63 static void *
  64 open_shared_memory(const char *filename, const size_t mem_size)
  65 {
  66         return map_shared_memory(filename, mem_size, O_RDWR);
  67 }
  68
  69 static void *
  70 create_shared_memory(const char *filename, const size_t mem_size)
  71 {
  72         return map_shared_memory(filename, mem_size, O_RDWR | O_CREAT);
  73 }
  74
  75 static int get_hp_sysfs_value(const char *subdir, const char *file, unsigned long *val)
  76 {
  77         char path[PATH_MAX];
  78
  79         snprintf(path, sizeof(path), "%s/%s/%s",
  80                         sys_dir_path, subdir, file);
  81         return eal_parse_sysfs_value(path, val);
  82 }
  83
  84 /* this function is only called from eal_hugepage_info_init which itself
  85  * is only called from a primary process */
  86 static uint32_t
  87 get_num_hugepages(const char *subdir, size_t sz)
  88 {
  89         unsigned long resv_pages, num_pages, over_pages, surplus_pages;
  90         const char *nr_hp_file = "free_hugepages";
  91         const char *nr_rsvd_file = "resv_hugepages";
  92         const char *nr_over_file = "nr_overcommit_hugepages";
  93         const char *nr_splus_file = "surplus_hugepages";
  94
  95         /* first, check how many reserved pages kernel reports */
  96         if (get_hp_sysfs_value(subdir, nr_rsvd_file, &resv_pages) < 0)
  97                 return 0;
  98
  99         if (get_hp_sysfs_value(subdir, nr_hp_file, &num_pages) < 0)
 100                 return 0;
 101
 102         if (get_hp_sysfs_value(subdir, nr_over_file, &over_pages) < 0)
 103                 over_pages = 0;
 104
 105         if (get_hp_sysfs_value(subdir, nr_splus_file, &surplus_pages) < 0)
 106                 surplus_pages = 0;
 107
 108         /* adjust num_pages */
 109         if (num_pages >= resv_pages)
 110                 num_pages -= resv_pages;
 111         else if (resv_pages)
 112                 num_pages = 0;
 113
 114         if (over_pages >= surplus_pages)
 115                 over_pages -= surplus_pages;
 116         else
 117                 over_pages = 0;
 118
 119         if (num_pages == 0 && over_pages == 0)
 120                 RTE_LOG(WARNING, EAL, "No available %zu kB hugepages reported\n",
 121                                 sz >> 10);
 122
 123         num_pages += over_pages;
 124         if (num_pages < over_pages) /* overflow */
 125                 num_pages = UINT32_MAX;
 126
 127         /* we want to return a uint32_t and more than this looks suspicious
 128          * anyway ... */
 129         if (num_pages > UINT32_MAX)
 130                 num_pages = UINT32_MAX;
 131
 132         return num_pages;
 133 }
 134
 135 static uint32_t
 136 get_num_hugepages_on_node(const char *subdir, unsigned int socket, size_t sz)
 137 {
 138         char path[PATH_MAX], socketpath[PATH_MAX];
 139         DIR *socketdir;
 140         unsigned long num_pages = 0;
 141         const char *nr_hp_file = "free_hugepages";
 142
 143         snprintf(socketpath, sizeof(socketpath), "%s/node%u/hugepages",
 144                 sys_pages_numa_dir_path, socket);
 145
 146         socketdir = opendir(socketpath);
 147         if (socketdir) {
 148                 /* Keep calm and carry on */
 149                 closedir(socketdir);
 150         } else {
 151                 /* Can't find socket dir, so ignore it */
 152                 return 0;
 153         }
 154
 155         snprintf(path, sizeof(path), "%s/%s/%s",
 156                         socketpath, subdir, nr_hp_file);
 157         if (eal_parse_sysfs_value(path, &num_pages) < 0)
 158                 return 0;
 159
 160         if (num_pages == 0)
 161                 RTE_LOG(WARNING, EAL, "No free %zu kB hugepages reported on node %u\n",
 162                                 sz >> 10, socket);
 163
 164         /*
 165          * we want to return a uint32_t and more than this looks suspicious
 166          * anyway ...
 167          */
 168         if (num_pages > UINT32_MAX)
 169                 num_pages = UINT32_MAX;
 170
 171         return num_pages;
 172 }
 173
 174 static uint64_t
 175 get_default_hp_size(void)
 176 {
 177         const char proc_meminfo[] = "/proc/meminfo";
 178         const char str_hugepagesz[] = "Hugepagesize:";
 179         unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
 180         char buffer[256];
 181         unsigned long long size = 0;
 182
 183         FILE *fd = fopen(proc_meminfo, "r");
 184         if (fd == NULL)
 185                 rte_panic("Cannot open %s\n", proc_meminfo);
 186         while(fgets(buffer, sizeof(buffer), fd)){
 187                 if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
 188                         size = rte_str_to_size(&buffer[hugepagesz_len]);
 189                         break;
 190                 }
 191         }
 192         fclose(fd);
 193         if (size == 0)
 194                 rte_panic("Cannot get default hugepage size from %s\n", proc_meminfo);
 195         return size;
 196 }
 197
 198 static int
 199 get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
 200 {
 201         enum proc_mount_fieldnames {
 202                 DEVICE = 0,
 203                 MOUNTPT,
 204                 FSTYPE,
 205                 OPTIONS,
 206                 _FIELDNAME_MAX
 207         };
 208         static uint64_t default_size = 0;
 209         const char proc_mounts[] = "/proc/mounts";
 210         const char hugetlbfs_str[] = "hugetlbfs";
 211         const size_t htlbfs_str_len = sizeof(hugetlbfs_str) - 1;
 212         const char pagesize_opt[] = "pagesize=";
 213         const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
 214         const char split_tok = ' ';
 215         char *splitstr[_FIELDNAME_MAX];
 216         char found[PATH_MAX] = "";
 217         char buf[BUFSIZ];
 218         const struct internal_config *internal_conf =
 219                 eal_get_internal_configuration();
 220         struct stat st;
 221
 222         /*
 223          * If the specified dir doesn't exist, we can't match it.
 224          */
 225         if (internal_conf->hugepage_dir != NULL &&
 226                 stat(internal_conf->hugepage_dir, &st) != 0) {
 227                 return -1;
 228         }
 229
 230         FILE *fd = fopen(proc_mounts, "r");
 231         if (fd == NULL)
 232                 rte_panic("Cannot open %s\n", proc_mounts);
 233
 234         if (default_size == 0)
 235                 default_size = get_default_hp_size();
 236
 237         while (fgets(buf, sizeof(buf), fd)){
 238                 const char *pagesz_str;
 239
 240                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 241                                 split_tok) != _FIELDNAME_MAX) {
 242                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 243                         break; /* return NULL */
 244                 }
 245
 246                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) != 0)
 247                         continue;
 248
 249                 pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 250
 251                 /* if no explicit page size, the default page size is compared */
 252                 if (pagesz_str == NULL) {
 253                         if (hugepage_sz != default_size)
 254                                 continue;
 255                 }
 256                 /* there is an explicit page size, so check it */
 257                 else {
 258                         uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 259                         if (pagesz != hugepage_sz)
 260                                 continue;
 261                 }
 262
 263                 /*
 264                  * If no --huge-dir option has been given, we're done.
 265                  */
 266                 if (internal_conf->hugepage_dir == NULL) {
 267                         strlcpy(found, splitstr[MOUNTPT], len);
 268                         break;
 269                 }
 270
 271                 /*
 272                  * Ignore any mount that doesn't contain the --huge-dir
 273                  * directory.
 274                  */
 275                 if (strncmp(internal_conf->hugepage_dir, splitstr[MOUNTPT],
 276                         strlen(splitstr[MOUNTPT])) != 0) {
 277                         continue;
 278                 }
 279
 280                 /*
 281                  * We found a match, but only prefer it if it's a longer match
 282                  * (so /mnt/1 is preferred over /mnt for matching /mnt/1/2)).
 283                  */
 284                 if (strlen(splitstr[MOUNTPT]) > strlen(found))
 285                         strlcpy(found, splitstr[MOUNTPT], len);
 286         } /* end while fgets */
 287
 288         fclose(fd);
 289
 290         if (found[0] != '\0') {
 291                 /* If needed, return the requested dir, not the mount point. */
 292                 strlcpy(hugedir, internal_conf->hugepage_dir != NULL ?
 293                         internal_conf->hugepage_dir : found, len);
 294                 return 0;
 295         }
 296
 297         return -1;
 298 }
 299
 300 /*
 301  * Clear the hugepage directory of whatever hugepage files
 302  * there are. Checks if the file is locked (i.e.
 303  * if it's in use by another DPDK process).
 304  */
 305 static int
 306 clear_hugedir(const char * hugedir)
 307 {
 308         DIR *dir;
 309         struct dirent *dirent;
 310         int dir_fd, fd, lck_result;
 311         const char filter[] = "*map_*"; /* matches hugepage files */
 312
 313         /* open directory */
 314         dir = opendir(hugedir);
 315         if (!dir) {
 316                 RTE_LOG(ERR, EAL, "Unable to open hugepage directory %s\n",
 317                                 hugedir);
 318                 goto error;
 319         }
 320         dir_fd = dirfd(dir);
 321
 322         dirent = readdir(dir);
 323         if (!dirent) {
 324                 RTE_LOG(ERR, EAL, "Unable to read hugepage directory %s\n",
 325                                 hugedir);
 326                 goto error;
 327         }
 328
 329         while(dirent != NULL){
 330                 /* skip files that don't match the hugepage pattern */
 331                 if (fnmatch(filter, dirent->d_name, 0) > 0) {
 332                         dirent = readdir(dir);
 333                         continue;
 334                 }
 335
 336                 /* try and lock the file */
 337                 fd = openat(dir_fd, dirent->d_name, O_RDONLY);
 338
 339                 /* skip to next file */
 340                 if (fd == -1) {
 341                         dirent = readdir(dir);
 342                         continue;
 343                 }
 344
 345                 /* non-blocking lock */
 346                 lck_result = flock(fd, LOCK_EX | LOCK_NB);
 347
 348                 /* if lock succeeds, remove the file */
 349                 if (lck_result != -1)
 350                         unlinkat(dir_fd, dirent->d_name, 0);
 351                 close (fd);
 352                 dirent = readdir(dir);
 353         }
 354
 355         closedir(dir);
 356         return 0;
 357
 358 error:
 359         if (dir)
 360                 closedir(dir);
 361
 362         RTE_LOG(ERR, EAL, "Error while clearing hugepage dir: %s\n",
 363                 strerror(errno));
 364
 365         return -1;
 366 }
 367
 368 static int
 369 compare_hpi(const void *a, const void *b)
 370 {
 371         const struct hugepage_info *hpi_a = a;
 372         const struct hugepage_info *hpi_b = b;
 373
 374         return hpi_b->hugepage_sz - hpi_a->hugepage_sz;
 375 }
 376
 377 static void
 378 calc_num_pages(struct hugepage_info *hpi, struct dirent *dirent)
 379 {
 380         uint64_t total_pages = 0;
 381         unsigned int i;
 382         const struct internal_config *internal_conf =
 383                 eal_get_internal_configuration();
 384
 385         /*
 386          * first, try to put all hugepages into relevant sockets, but
 387          * if first attempts fails, fall back to collecting all pages
 388          * in one socket and sorting them later
 389          */
 390         total_pages = 0;
 391         /* we also don't want to do this for legacy init */
 392         if (!internal_conf->legacy_mem)
 393                 for (i = 0; i < rte_socket_count(); i++) {
 394                         int socket = rte_socket_id_by_idx(i);
 395                         unsigned int num_pages =
 396                                         get_num_hugepages_on_node(
 397                                                 dirent->d_name, socket,
 398                                                 hpi->hugepage_sz);
 399                         hpi->num_pages[socket] = num_pages;
 400                         total_pages += num_pages;
 401                 }
 402         /*
 403          * we failed to sort memory from the get go, so fall
 404          * back to old way
 405          */
 406         if (total_pages == 0) {
 407                 hpi->num_pages[0] = get_num_hugepages(dirent->d_name,
 408                                 hpi->hugepage_sz);
 409
 410 #ifndef RTE_ARCH_64
 411                 /* for 32-bit systems, limit number of hugepages to
 412                  * 1GB per page size */
 413                 hpi->num_pages[0] = RTE_MIN(hpi->num_pages[0],
 414                                 RTE_PGSIZE_1G / hpi->hugepage_sz);
 415 #endif
 416         }
 417 }
 418
 419 static int
 420 hugepage_info_init(void)
 421 {       const char dirent_start_text[] = "hugepages-";
 422         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 423         unsigned int i, num_sizes = 0;
 424         DIR *dir;
 425         struct dirent *dirent;
 426         struct internal_config *internal_conf =
 427                 eal_get_internal_configuration();
 428
 429         dir = opendir(sys_dir_path);
 430         if (dir == NULL) {
 431                 RTE_LOG(ERR, EAL,
 432                         "Cannot open directory %s to read system hugepage info\n",
 433                         sys_dir_path);
 434                 return -1;
 435         }
 436
 437         for (dirent = readdir(dir); dirent != NULL; dirent = readdir(dir)) {
 438                 struct hugepage_info *hpi;
 439
 440                 if (strncmp(dirent->d_name, dirent_start_text,
 441                             dirent_start_len) != 0)
 442                         continue;
 443
 444                 if (num_sizes >= MAX_HUGEPAGE_SIZES)
 445                         break;
 446
 447                 hpi = &internal_conf->hugepage_info[num_sizes];
 448                 hpi->hugepage_sz =
 449                         rte_str_to_size(&dirent->d_name[dirent_start_len]);
 450
 451                 /* first, check if we have a mountpoint */
 452                 if (get_hugepage_dir(hpi->hugepage_sz,
 453                         hpi->hugedir, sizeof(hpi->hugedir)) < 0) {
 454                         uint32_t num_pages;
 455
 456                         num_pages = get_num_hugepages(dirent->d_name,
 457                                         hpi->hugepage_sz);
 458                         if (num_pages > 0)
 459                                 RTE_LOG(NOTICE, EAL,
 460                                         "%" PRIu32 " hugepages of size "
 461                                         "%" PRIu64 " reserved, but no mounted "
 462                                         "hugetlbfs found for that size\n",
 463                                         num_pages, hpi->hugepage_sz);
 464                         /* if we have kernel support for reserving hugepages
 465                          * through mmap, and we're in in-memory mode, treat this
 466                          * page size as valid. we cannot be in legacy mode at
 467                          * this point because we've checked this earlier in the
 468                          * init process.
 469                          */
 470 #ifdef MAP_HUGE_SHIFT
 471                         if (internal_conf->in_memory) {
 472                                 RTE_LOG(DEBUG, EAL, "In-memory mode enabled, "
 473                                         "hugepages of size %" PRIu64 " bytes "
 474                                         "will be allocated anonymously\n",
 475                                         hpi->hugepage_sz);
 476                                 calc_num_pages(hpi, dirent);
 477                                 num_sizes++;
 478                         }
 479 #endif
 480                         continue;
 481                 }
 482
 483                 /* try to obtain a writelock */
 484                 hpi->lock_descriptor = open(hpi->hugedir, O_RDONLY);
 485
 486                 /* if blocking lock failed */
 487                 if (flock(hpi->lock_descriptor, LOCK_EX) == -1) {
 488                         RTE_LOG(CRIT, EAL,
 489                                 "Failed to lock hugepage directory!\n");
 490                         break;
 491                 }
 492                 /* clear out the hugepages dir from unused pages */
 493                 if (clear_hugedir(hpi->hugedir) == -1)
 494                         break;
 495
 496                 calc_num_pages(hpi, dirent);
 497
 498                 num_sizes++;
 499         }
 500         closedir(dir);
 501
 502         /* something went wrong, and we broke from the for loop above */
 503         if (dirent != NULL)
 504                 return -1;
 505
 506         internal_conf->num_hugepage_sizes = num_sizes;
 507
 508         /* sort the page directory entries by size, largest to smallest */
 509         qsort(&internal_conf->hugepage_info[0], num_sizes,
 510               sizeof(internal_conf->hugepage_info[0]), compare_hpi);
 511
 512         /* now we have all info, check we have at least one valid size */
 513         for (i = 0; i < num_sizes; i++) {
 514                 /* pages may no longer all be on socket 0, so check all */
 515                 unsigned int j, num_pages = 0;
 516                 struct hugepage_info *hpi = &internal_conf->hugepage_info[i];
 517
 518                 for (j = 0; j < RTE_MAX_NUMA_NODES; j++)
 519                         num_pages += hpi->num_pages[j];
 520                 if (num_pages > 0)
 521                         return 0;
 522         }
 523
 524         /* no valid hugepage mounts available, return error */
 525         return -1;
 526 }
 527
 528 /*
 529  * when we initialize the hugepage info, everything goes
 530  * to socket 0 by default. it will later get sorted by memory
 531  * initialization procedure.
 532  */
 533 int
 534 eal_hugepage_info_init(void)
 535 {
 536         struct hugepage_info *hpi, *tmp_hpi;
 537         unsigned int i;
 538         struct internal_config *internal_conf =
 539                 eal_get_internal_configuration();
 540
 541         if (hugepage_info_init() < 0)
 542                 return -1;
 543
 544         /* for no shared files mode, we're done */
 545         if (internal_conf->no_shconf)
 546                 return 0;
 547
 548         hpi = &internal_conf->hugepage_info[0];
 549
 550         tmp_hpi = create_shared_memory(eal_hugepage_info_path(),
 551                         sizeof(internal_conf->hugepage_info));
 552         if (tmp_hpi == NULL) {
 553                 RTE_LOG(ERR, EAL, "Failed to create shared memory!\n");
 554                 return -1;
 555         }
 556
 557         memcpy(tmp_hpi, hpi, sizeof(internal_conf->hugepage_info));
 558
 559         /* we've copied file descriptors along with everything else, but they
 560          * will be invalid in secondary process, so overwrite them
 561          */
 562         for (i = 0; i < RTE_DIM(internal_conf->hugepage_info); i++) {
 563                 struct hugepage_info *tmp = &tmp_hpi[i];
 564                 tmp->lock_descriptor = -1;
 565         }
 566
 567         if (munmap(tmp_hpi, sizeof(internal_conf->hugepage_info)) < 0) {
 568                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 569                 return -1;
 570         }
 571         return 0;
 572 }
 573
 574 int eal_hugepage_info_read(void)
 575 {
 576         struct internal_config *internal_conf =
 577                 eal_get_internal_configuration();
 578         struct hugepage_info *hpi = &internal_conf->hugepage_info[0];
 579         struct hugepage_info *tmp_hpi;
 580
 581         tmp_hpi = open_shared_memory(eal_hugepage_info_path(),
 582                                   sizeof(internal_conf->hugepage_info));
 583         if (tmp_hpi == NULL) {
 584                 RTE_LOG(ERR, EAL, "Failed to open shared memory!\n");
 585                 return -1;
 586         }
 587
 588         memcpy(hpi, tmp_hpi, sizeof(internal_conf->hugepage_info));
 589
 590         if (munmap(tmp_hpi, sizeof(internal_conf->hugepage_info)) < 0) {
 591                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 592                 return -1;
 593         }
 594         return 0;
 595 }