lib/librte_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)
  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 hugepages reported in %s\n",
 121                                 subdir);
 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)
 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 hugepages reported in %s\n",
 162                                 subdir);
 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 buf[BUFSIZ];
 217         int retval = -1;
 218         const struct internal_config *internal_conf =
 219                 eal_get_internal_configuration();
 220
 221         FILE *fd = fopen(proc_mounts, "r");
 222         if (fd == NULL)
 223                 rte_panic("Cannot open %s\n", proc_mounts);
 224
 225         if (default_size == 0)
 226                 default_size = get_default_hp_size();
 227
 228         while (fgets(buf, sizeof(buf), fd)){
 229                 if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
 230                                 split_tok) != _FIELDNAME_MAX) {
 231                         RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
 232                         break; /* return NULL */
 233                 }
 234
 235                 /* we have a specified --huge-dir option, only examine that dir */
 236                 if (internal_conf->hugepage_dir != NULL &&
 237                                 strcmp(splitstr[MOUNTPT], internal_conf->hugepage_dir) != 0)
 238                         continue;
 239
 240                 if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
 241                         const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 242
 243                         /* if no explicit page size, the default page size is compared */
 244                         if (pagesz_str == NULL){
 245                                 if (hugepage_sz == default_size){
 246                                         strlcpy(hugedir, splitstr[MOUNTPT], len);
 247                                         retval = 0;
 248                                         break;
 249                                 }
 250                         }
 251                         /* there is an explicit page size, so check it */
 252                         else {
 253                                 uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
 254                                 if (pagesz == hugepage_sz) {
 255                                         strlcpy(hugedir, splitstr[MOUNTPT], len);
 256                                         retval = 0;
 257                                         break;
 258                                 }
 259                         }
 260                 } /* end if strncmp hugetlbfs */
 261         } /* end while fgets */
 262
 263         fclose(fd);
 264         return retval;
 265 }
 266
 267 /*
 268  * Clear the hugepage directory of whatever hugepage files
 269  * there are. Checks if the file is locked (i.e.
 270  * if it's in use by another DPDK process).
 271  */
 272 static int
 273 clear_hugedir(const char * hugedir)
 274 {
 275         DIR *dir;
 276         struct dirent *dirent;
 277         int dir_fd, fd, lck_result;
 278         const char filter[] = "*map_*"; /* matches hugepage files */
 279
 280         /* open directory */
 281         dir = opendir(hugedir);
 282         if (!dir) {
 283                 RTE_LOG(ERR, EAL, "Unable to open hugepage directory %s\n",
 284                                 hugedir);
 285                 goto error;
 286         }
 287         dir_fd = dirfd(dir);
 288
 289         dirent = readdir(dir);
 290         if (!dirent) {
 291                 RTE_LOG(ERR, EAL, "Unable to read hugepage directory %s\n",
 292                                 hugedir);
 293                 goto error;
 294         }
 295
 296         while(dirent != NULL){
 297                 /* skip files that don't match the hugepage pattern */
 298                 if (fnmatch(filter, dirent->d_name, 0) > 0) {
 299                         dirent = readdir(dir);
 300                         continue;
 301                 }
 302
 303                 /* try and lock the file */
 304                 fd = openat(dir_fd, dirent->d_name, O_RDONLY);
 305
 306                 /* skip to next file */
 307                 if (fd == -1) {
 308                         dirent = readdir(dir);
 309                         continue;
 310                 }
 311
 312                 /* non-blocking lock */
 313                 lck_result = flock(fd, LOCK_EX | LOCK_NB);
 314
 315                 /* if lock succeeds, remove the file */
 316                 if (lck_result != -1)
 317                         unlinkat(dir_fd, dirent->d_name, 0);
 318                 close (fd);
 319                 dirent = readdir(dir);
 320         }
 321
 322         closedir(dir);
 323         return 0;
 324
 325 error:
 326         if (dir)
 327                 closedir(dir);
 328
 329         RTE_LOG(ERR, EAL, "Error while clearing hugepage dir: %s\n",
 330                 strerror(errno));
 331
 332         return -1;
 333 }
 334
 335 static int
 336 compare_hpi(const void *a, const void *b)
 337 {
 338         const struct hugepage_info *hpi_a = a;
 339         const struct hugepage_info *hpi_b = b;
 340
 341         return hpi_b->hugepage_sz - hpi_a->hugepage_sz;
 342 }
 343
 344 static void
 345 calc_num_pages(struct hugepage_info *hpi, struct dirent *dirent)
 346 {
 347         uint64_t total_pages = 0;
 348         unsigned int i;
 349         const struct internal_config *internal_conf =
 350                 eal_get_internal_configuration();
 351
 352         /*
 353          * first, try to put all hugepages into relevant sockets, but
 354          * if first attempts fails, fall back to collecting all pages
 355          * in one socket and sorting them later
 356          */
 357         total_pages = 0;
 358         /* we also don't want to do this for legacy init */
 359         if (!internal_conf->legacy_mem)
 360                 for (i = 0; i < rte_socket_count(); i++) {
 361                         int socket = rte_socket_id_by_idx(i);
 362                         unsigned int num_pages =
 363                                         get_num_hugepages_on_node(
 364                                                 dirent->d_name, socket);
 365                         hpi->num_pages[socket] = num_pages;
 366                         total_pages += num_pages;
 367                 }
 368         /*
 369          * we failed to sort memory from the get go, so fall
 370          * back to old way
 371          */
 372         if (total_pages == 0) {
 373                 hpi->num_pages[0] = get_num_hugepages(dirent->d_name);
 374
 375 #ifndef RTE_ARCH_64
 376                 /* for 32-bit systems, limit number of hugepages to
 377                  * 1GB per page size */
 378                 hpi->num_pages[0] = RTE_MIN(hpi->num_pages[0],
 379                                 RTE_PGSIZE_1G / hpi->hugepage_sz);
 380 #endif
 381         }
 382 }
 383
 384 static int
 385 hugepage_info_init(void)
 386 {       const char dirent_start_text[] = "hugepages-";
 387         const size_t dirent_start_len = sizeof(dirent_start_text) - 1;
 388         unsigned int i, num_sizes = 0;
 389         DIR *dir;
 390         struct dirent *dirent;
 391         struct internal_config *internal_conf =
 392                 eal_get_internal_configuration();
 393
 394         dir = opendir(sys_dir_path);
 395         if (dir == NULL) {
 396                 RTE_LOG(ERR, EAL,
 397                         "Cannot open directory %s to read system hugepage info\n",
 398                         sys_dir_path);
 399                 return -1;
 400         }
 401
 402         for (dirent = readdir(dir); dirent != NULL; dirent = readdir(dir)) {
 403                 struct hugepage_info *hpi;
 404
 405                 if (strncmp(dirent->d_name, dirent_start_text,
 406                             dirent_start_len) != 0)
 407                         continue;
 408
 409                 if (num_sizes >= MAX_HUGEPAGE_SIZES)
 410                         break;
 411
 412                 hpi = &internal_conf->hugepage_info[num_sizes];
 413                 hpi->hugepage_sz =
 414                         rte_str_to_size(&dirent->d_name[dirent_start_len]);
 415
 416                 /* first, check if we have a mountpoint */
 417                 if (get_hugepage_dir(hpi->hugepage_sz,
 418                         hpi->hugedir, sizeof(hpi->hugedir)) < 0) {
 419                         uint32_t num_pages;
 420
 421                         num_pages = get_num_hugepages(dirent->d_name);
 422                         if (num_pages > 0)
 423                                 RTE_LOG(NOTICE, EAL,
 424                                         "%" PRIu32 " hugepages of size "
 425                                         "%" PRIu64 " reserved, but no mounted "
 426                                         "hugetlbfs found for that size\n",
 427                                         num_pages, hpi->hugepage_sz);
 428                         /* if we have kernel support for reserving hugepages
 429                          * through mmap, and we're in in-memory mode, treat this
 430                          * page size as valid. we cannot be in legacy mode at
 431                          * this point because we've checked this earlier in the
 432                          * init process.
 433                          */
 434 #ifdef MAP_HUGE_SHIFT
 435                         if (internal_conf->in_memory) {
 436                                 RTE_LOG(DEBUG, EAL, "In-memory mode enabled, "
 437                                         "hugepages of size %" PRIu64 " bytes "
 438                                         "will be allocated anonymously\n",
 439                                         hpi->hugepage_sz);
 440                                 calc_num_pages(hpi, dirent);
 441                                 num_sizes++;
 442                         }
 443 #endif
 444                         continue;
 445                 }
 446
 447                 /* try to obtain a writelock */
 448                 hpi->lock_descriptor = open(hpi->hugedir, O_RDONLY);
 449
 450                 /* if blocking lock failed */
 451                 if (flock(hpi->lock_descriptor, LOCK_EX) == -1) {
 452                         RTE_LOG(CRIT, EAL,
 453                                 "Failed to lock hugepage directory!\n");
 454                         break;
 455                 }
 456                 /* clear out the hugepages dir from unused pages */
 457                 if (clear_hugedir(hpi->hugedir) == -1)
 458                         break;
 459
 460                 calc_num_pages(hpi, dirent);
 461
 462                 num_sizes++;
 463         }
 464         closedir(dir);
 465
 466         /* something went wrong, and we broke from the for loop above */
 467         if (dirent != NULL)
 468                 return -1;
 469
 470         internal_conf->num_hugepage_sizes = num_sizes;
 471
 472         /* sort the page directory entries by size, largest to smallest */
 473         qsort(&internal_conf->hugepage_info[0], num_sizes,
 474               sizeof(internal_conf->hugepage_info[0]), compare_hpi);
 475
 476         /* now we have all info, check we have at least one valid size */
 477         for (i = 0; i < num_sizes; i++) {
 478                 /* pages may no longer all be on socket 0, so check all */
 479                 unsigned int j, num_pages = 0;
 480                 struct hugepage_info *hpi = &internal_conf->hugepage_info[i];
 481
 482                 for (j = 0; j < RTE_MAX_NUMA_NODES; j++)
 483                         num_pages += hpi->num_pages[j];
 484                 if (num_pages > 0)
 485                         return 0;
 486         }
 487
 488         /* no valid hugepage mounts available, return error */
 489         return -1;
 490 }
 491
 492 /*
 493  * when we initialize the hugepage info, everything goes
 494  * to socket 0 by default. it will later get sorted by memory
 495  * initialization procedure.
 496  */
 497 int
 498 eal_hugepage_info_init(void)
 499 {
 500         struct hugepage_info *hpi, *tmp_hpi;
 501         unsigned int i;
 502         struct internal_config *internal_conf =
 503                 eal_get_internal_configuration();
 504
 505         if (hugepage_info_init() < 0)
 506                 return -1;
 507
 508         /* for no shared files mode, we're done */
 509         if (internal_conf->no_shconf)
 510                 return 0;
 511
 512         hpi = &internal_conf->hugepage_info[0];
 513
 514         tmp_hpi = create_shared_memory(eal_hugepage_info_path(),
 515                         sizeof(internal_conf->hugepage_info));
 516         if (tmp_hpi == NULL) {
 517                 RTE_LOG(ERR, EAL, "Failed to create shared memory!\n");
 518                 return -1;
 519         }
 520
 521         memcpy(tmp_hpi, hpi, sizeof(internal_conf->hugepage_info));
 522
 523         /* we've copied file descriptors along with everything else, but they
 524          * will be invalid in secondary process, so overwrite them
 525          */
 526         for (i = 0; i < RTE_DIM(internal_conf->hugepage_info); i++) {
 527                 struct hugepage_info *tmp = &tmp_hpi[i];
 528                 tmp->lock_descriptor = -1;
 529         }
 530
 531         if (munmap(tmp_hpi, sizeof(internal_conf->hugepage_info)) < 0) {
 532                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 533                 return -1;
 534         }
 535         return 0;
 536 }
 537
 538 int eal_hugepage_info_read(void)
 539 {
 540         struct internal_config *internal_conf =
 541                 eal_get_internal_configuration();
 542         struct hugepage_info *hpi = &internal_conf->hugepage_info[0];
 543         struct hugepage_info *tmp_hpi;
 544
 545         tmp_hpi = open_shared_memory(eal_hugepage_info_path(),
 546                                   sizeof(internal_conf->hugepage_info));
 547         if (tmp_hpi == NULL) {
 548                 RTE_LOG(ERR, EAL, "Failed to open shared memory!\n");
 549                 return -1;
 550         }
 551
 552         memcpy(hpi, tmp_hpi, sizeof(internal_conf->hugepage_info));
 553
 554         if (munmap(tmp_hpi, sizeof(internal_conf->hugepage_info)) < 0) {
 555                 RTE_LOG(ERR, EAL, "Failed to unmap shared memory!\n");
 556                 return -1;
 557         }
 558         return 0;
 559 }