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