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