src/proc_cpuview.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef _GNU_SOURCE
   4 #define _GNU_SOURCE
   5 #endif
   6
   7 #ifndef FUSE_USE_VERSION
   8 #define FUSE_USE_VERSION 26
   9 #endif
  10
  11 #define _FILE_OFFSET_BITS 64
  12
  13 #define __STDC_FORMAT_MACROS
  14 #include <dirent.h>
  15 #include <errno.h>
  16 #include <fcntl.h>
  17 #include <fuse.h>
  18 #include <inttypes.h>
  19 #include <libgen.h>
  20 #include <pthread.h>
  21 #include <sched.h>
  22 #include <stdarg.h>
  23 #include <stdbool.h>
  24 #include <stdint.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <time.h>
  29 #include <unistd.h>
  30 #include <wait.h>
  31 #include <linux/magic.h>
  32 #include <linux/sched.h>
  33 #include <sys/epoll.h>
  34 #include <sys/mman.h>
  35 #include <sys/mount.h>
  36 #include <sys/param.h>
  37 #include <sys/socket.h>
  38 #include <sys/syscall.h>
  39 #include <sys/sysinfo.h>
  40 #include <sys/vfs.h>
  41
  42 #include "bindings.h"
  43 #include "config.h"
  44 #include "cgroup_fuse.h"
  45 #include "cpuset_parse.h"
  46 #include "cgroups/cgroup.h"
  47 #include "cgroups/cgroup_utils.h"
  48 #include "memory_utils.h"
  49 #include "proc_loadavg.h"
  50 #include "utils.h"
  51
  52 /* Data for CPU view */
  53 struct cg_proc_stat {
  54         char *cg;
  55         struct cpuacct_usage *usage; // Real usage as read from the host's /proc/stat
  56         struct cpuacct_usage *view; // Usage stats reported to the container
  57         int cpu_count;
  58         pthread_mutex_t lock; // For node manipulation
  59         struct cg_proc_stat *next;
  60 };
  61
  62 struct cg_proc_stat_head {
  63         struct cg_proc_stat *next;
  64         time_t lastcheck;
  65
  66         /*
  67          * For access to the list. Reading can be parallel, pruning is exclusive.
  68          */
  69         pthread_rwlock_t lock;
  70 };
  71
  72 #define CPUVIEW_HASH_SIZE 100
  73 static struct cg_proc_stat_head *proc_stat_history[CPUVIEW_HASH_SIZE];
  74
  75 static void reset_proc_stat_node(struct cg_proc_stat *node,
  76                                  struct cpuacct_usage *usage, int cpu_count)
  77 {
  78         lxcfs_debug("Resetting stat node for %s\n", node->cg);
  79         memcpy(node->usage, usage, sizeof(struct cpuacct_usage) * cpu_count);
  80
  81         for (int i = 0; i < cpu_count; i++) {
  82                 node->view[i].user = 0;
  83                 node->view[i].system = 0;
  84                 node->view[i].idle = 0;
  85         }
  86
  87         node->cpu_count = cpu_count;
  88 }
  89
  90 static bool expand_proc_stat_node(struct cg_proc_stat *node, int cpu_count)
  91 {
  92         __do_free struct cpuacct_usage *new_usage = NULL, *new_view = NULL;
  93
  94         /* Allocate new memory */
  95         new_usage = malloc(sizeof(struct cpuacct_usage) * cpu_count);
  96         if (!new_usage)
  97                 return false;
  98
  99         new_view = malloc(sizeof(struct cpuacct_usage) * cpu_count);
 100         if (!new_view)
 101                 return false;
 102
 103         /* Copy existing data & initialize new elements */
 104         for (int i = 0; i < cpu_count; i++) {
 105                 if (i < node->cpu_count) {
 106                         new_usage[i].user = node->usage[i].user;
 107                         new_usage[i].system = node->usage[i].system;
 108                         new_usage[i].idle = node->usage[i].idle;
 109
 110                         new_view[i].user = node->view[i].user;
 111                         new_view[i].system = node->view[i].system;
 112                         new_view[i].idle = node->view[i].idle;
 113                 } else {
 114                         new_usage[i].user = 0;
 115                         new_usage[i].system = 0;
 116                         new_usage[i].idle = 0;
 117
 118                         new_view[i].user = 0;
 119                         new_view[i].system = 0;
 120                         new_view[i].idle = 0;
 121                 }
 122         }
 123
 124         free(node->usage);
 125         node->usage = move_ptr(new_usage);
 126
 127         free(node->view);
 128         node->view = move_ptr(new_view);
 129         node->cpu_count = cpu_count;
 130
 131         return true;
 132 }
 133
 134 static void free_proc_stat_node(struct cg_proc_stat *node)
 135 {
 136         pthread_mutex_destroy(&node->lock);
 137         free_disarm(node->cg);
 138         free_disarm(node->usage);
 139         free_disarm(node->view);
 140         free_disarm(node);
 141 }
 142
 143 static struct cg_proc_stat *add_proc_stat_node(struct cg_proc_stat *new_node)
 144 {
 145         int hash = calc_hash(new_node->cg) % CPUVIEW_HASH_SIZE;
 146         struct cg_proc_stat_head *head = proc_stat_history[hash];
 147         struct cg_proc_stat *node, *rv = new_node;
 148
 149         pthread_rwlock_wrlock(&head->lock);
 150
 151         if (!head->next) {
 152                 head->next = new_node;
 153                 goto out;
 154         }
 155
 156         node = head->next;
 157
 158         for (;;) {
 159                 if (strcmp(node->cg, new_node->cg) == 0) {
 160                         /* The node is already present, return it */
 161                         free_proc_stat_node(new_node);
 162                         rv = node;
 163                         goto out;
 164                 }
 165
 166                 if (node->next) {
 167                         node = node->next;
 168                         continue;
 169                 }
 170
 171                 node->next = new_node;
 172                 goto out;
 173         }
 174
 175 out:
 176         pthread_rwlock_unlock(&head->lock);
 177         return rv;
 178 }
 179
 180 static struct cg_proc_stat *new_proc_stat_node(struct cpuacct_usage *usage, int cpu_count, const char *cg)
 181 {
 182         struct cg_proc_stat *node;
 183         int i;
 184
 185         node = malloc(sizeof(struct cg_proc_stat));
 186         if (!node)
 187                 goto err;
 188
 189         node->cg = NULL;
 190         node->usage = NULL;
 191         node->view = NULL;
 192
 193         node->cg = malloc(strlen(cg) + 1);
 194         if (!node->cg)
 195                 goto err;
 196
 197         strcpy(node->cg, cg);
 198
 199         node->usage = malloc(sizeof(struct cpuacct_usage) * cpu_count);
 200         if (!node->usage)
 201                 goto err;
 202
 203         memcpy(node->usage, usage, sizeof(struct cpuacct_usage) * cpu_count);
 204
 205         node->view = malloc(sizeof(struct cpuacct_usage) * cpu_count);
 206         if (!node->view)
 207                 goto err;
 208
 209         node->cpu_count = cpu_count;
 210         node->next = NULL;
 211
 212         if (pthread_mutex_init(&node->lock, NULL) != 0)
 213                 log_error(goto err, "Failed to initialize node lock");
 214
 215         for (i = 0; i < cpu_count; i++) {
 216                 node->view[i].user = 0;
 217                 node->view[i].system = 0;
 218                 node->view[i].idle = 0;
 219         }
 220
 221         return node;
 222
 223 err:
 224         if (node && node->cg)
 225                 free(node->cg);
 226         if (node && node->usage)
 227                 free(node->usage);
 228         if (node && node->view)
 229                 free(node->view);
 230         if (node)
 231                 free(node);
 232
 233         return NULL;
 234 }
 235
 236 static bool cgfs_param_exist(const char *controller, const char *cgroup,
 237                              const char *file)
 238 {
 239         __do_free char *path = NULL;
 240         int cfd;
 241
 242         cfd = get_cgroup_fd(controller);
 243         if (cfd < 0)
 244                 return false;
 245
 246         path = must_make_path(dot_or_empty(cgroup), cgroup, file, NULL);
 247         return (faccessat(cfd, path, F_OK, 0) == 0);
 248 }
 249
 250 static struct cg_proc_stat *prune_proc_stat_list(struct cg_proc_stat *node)
 251 {
 252         struct cg_proc_stat *first = NULL;
 253
 254         for (struct cg_proc_stat *prev = NULL; node; ) {
 255                 if (!cgfs_param_exist("cpu", node->cg, "cpu.shares")) {
 256                         struct cg_proc_stat *tmp = node;
 257
 258                         lxcfs_debug("Removing stat node for %s\n", node->cg);
 259
 260                         if (prev)
 261                                 prev->next = node->next;
 262                         else
 263                                 first = node->next;
 264
 265                         node = node->next;
 266                         free_proc_stat_node(tmp);
 267                 } else {
 268                         if (!first)
 269                                 first = node;
 270                         prev = node;
 271                         node = node->next;
 272                 }
 273         }
 274
 275         return first;
 276 }
 277
 278 #define PROC_STAT_PRUNE_INTERVAL 10
 279 static void prune_proc_stat_history(void)
 280 {
 281         time_t now = time(NULL);
 282
 283         for (int i = 0; i < CPUVIEW_HASH_SIZE; i++) {
 284                 pthread_rwlock_wrlock(&proc_stat_history[i]->lock);
 285
 286                 if ((proc_stat_history[i]->lastcheck + PROC_STAT_PRUNE_INTERVAL) > now) {
 287                         pthread_rwlock_unlock(&proc_stat_history[i]->lock);
 288                         return;
 289                 }
 290
 291                 if (proc_stat_history[i]->next) {
 292                         proc_stat_history[i]->next = prune_proc_stat_list(proc_stat_history[i]->next);
 293                         proc_stat_history[i]->lastcheck = now;
 294                 }
 295
 296                 pthread_rwlock_unlock(&proc_stat_history[i]->lock);
 297         }
 298 }
 299
 300 static struct cg_proc_stat *find_proc_stat_node(struct cg_proc_stat_head *head,
 301                                                 const char *cg)
 302 {
 303         struct cg_proc_stat *node;
 304
 305         pthread_rwlock_rdlock(&head->lock);
 306
 307         if (!head->next) {
 308                 pthread_rwlock_unlock(&head->lock);
 309                 return NULL;
 310         }
 311
 312         node = head->next;
 313
 314         do {
 315                 if (strcmp(cg, node->cg) == 0)
 316                         goto out;
 317         } while ((node = node->next));
 318
 319         node = NULL;
 320
 321 out:
 322         pthread_rwlock_unlock(&head->lock);
 323         prune_proc_stat_history();
 324         return node;
 325 }
 326
 327 static struct cg_proc_stat *find_or_create_proc_stat_node(struct cpuacct_usage *usage, int cpu_count, const char *cg)
 328 {
 329         int hash = calc_hash(cg) % CPUVIEW_HASH_SIZE;
 330         struct cg_proc_stat_head *head = proc_stat_history[hash];
 331         struct cg_proc_stat *node;
 332
 333         node = find_proc_stat_node(head, cg);
 334         if (!node) {
 335                 node = new_proc_stat_node(usage, cpu_count, cg);
 336                 if (!node)
 337                         return NULL;
 338
 339                 node = add_proc_stat_node(node);
 340                 lxcfs_debug("New stat node (%d) for %s\n", cpu_count, cg);
 341         }
 342
 343         pthread_mutex_lock(&node->lock);
 344
 345         /* If additional CPUs on the host have been enabled, CPU usage counter
 346          * arrays have to be expanded */
 347         if (node->cpu_count < cpu_count) {
 348                 lxcfs_debug("Expanding stat node %d->%d for %s\n",
 349                                 node->cpu_count, cpu_count, cg);
 350
 351                 if (!expand_proc_stat_node(node, cpu_count)) {
 352                         pthread_mutex_unlock(&node->lock);
 353                         return log_debug(NULL, "Unable to expand stat node %d->%d for %s", node->cpu_count, cpu_count, cg);
 354                 }
 355         }
 356
 357         return node;
 358 }
 359
 360 static void add_cpu_usage(uint64_t *surplus, struct cpuacct_usage *usage,
 361                           uint64_t *counter, uint64_t threshold)
 362 {
 363         unsigned long free_space, to_add;
 364
 365         free_space = threshold - usage->user - usage->system;
 366
 367         if (free_space > usage->idle)
 368                 free_space = usage->idle;
 369
 370         to_add = free_space > *surplus ? *surplus : free_space;
 371
 372         *counter += to_add;
 373         usage->idle -= to_add;
 374         *surplus -= to_add;
 375 }
 376
 377 static unsigned long diff_cpu_usage(struct cpuacct_usage *older,
 378                                     struct cpuacct_usage *newer,
 379                                     struct cpuacct_usage *diff, int cpu_count)
 380 {
 381         unsigned long sum = 0;
 382
 383         for (int i = 0; i < cpu_count; i++) {
 384                 if (!newer[i].online)
 385                         continue;
 386
 387                 /*
 388                  * When cpuset is changed on the fly, the CPUs might get
 389                  * reordered. We could either reset all counters, or check
 390                  * that the substractions below will return expected results.
 391                  */
 392                 if (newer[i].user > older[i].user)
 393                         diff[i].user = newer[i].user - older[i].user;
 394                 else
 395                         diff[i].user = 0;
 396
 397                 if (newer[i].system > older[i].system)
 398                         diff[i].system = newer[i].system - older[i].system;
 399                 else
 400                         diff[i].system = 0;
 401
 402                 if (newer[i].idle > older[i].idle)
 403                         diff[i].idle = newer[i].idle - older[i].idle;
 404                 else
 405                         diff[i].idle = 0;
 406
 407                 sum += diff[i].user;
 408                 sum += diff[i].system;
 409                 sum += diff[i].idle;
 410         }
 411
 412         return sum;
 413 }
 414
 415 /*
 416  * Read cgroup CPU quota parameters from `cpu.cfs_quota_us` or
 417  * `cpu.cfs_period_us`, depending on `param`. Parameter value is returned
 418  * throuh `value`.
 419  */
 420 static bool read_cpu_cfs_param(const char *cg, const char *param, int64_t *value)
 421 {
 422         __do_free char *str = NULL;
 423         char file[11 + 6 + 1]; /* cpu.cfs__us + quota/period + \0 */
 424
 425         snprintf(file, sizeof(file), "cpu.cfs_%s_us", param);
 426
 427         if (!cgroup_ops->get(cgroup_ops, "cpu", cg, file, &str))
 428                 return false;
 429
 430         if (sscanf(str, "%"PRId64, value) != 1)
 431                 return false;
 432
 433         return true;
 434 }
 435
 436 /*
 437  * Return the exact number of visible CPUs based on CPU quotas.
 438  * If there is no quota set, zero is returned.
 439  */
 440 static double exact_cpu_count(const char *cg)
 441 {
 442         double rv;
 443         int nprocs;
 444         int64_t cfs_quota, cfs_period;
 445
 446         if (!read_cpu_cfs_param(cg, "quota", &cfs_quota))
 447                 return 0;
 448
 449         if (!read_cpu_cfs_param(cg, "period", &cfs_period))
 450                 return 0;
 451
 452         if (cfs_quota <= 0 || cfs_period <= 0)
 453                 return 0;
 454
 455         rv = (double)cfs_quota / (double)cfs_period;
 456
 457         nprocs = get_nprocs();
 458
 459         if (rv > nprocs)
 460                 rv = nprocs;
 461
 462         return rv;
 463 }
 464
 465 /*
 466  * Return the maximum number of visible CPUs based on CPU quotas.
 467  * If there is no quota set, zero is returned.
 468  */
 469 int max_cpu_count(const char *cg)
 470 {
 471         __do_free char *cpuset = NULL;
 472         int rv, nprocs;
 473         int64_t cfs_quota, cfs_period;
 474         int nr_cpus_in_cpuset = 0;
 475
 476         if (!read_cpu_cfs_param(cg, "quota", &cfs_quota))
 477                 return 0;
 478
 479         if (!read_cpu_cfs_param(cg, "period", &cfs_period))
 480                 return 0;
 481
 482         cpuset = get_cpuset(cg);
 483         if (cpuset)
 484                 nr_cpus_in_cpuset = cpu_number_in_cpuset(cpuset);
 485
 486         if (cfs_quota <= 0 || cfs_period <= 0){
 487                 if (nr_cpus_in_cpuset > 0)
 488                         return nr_cpus_in_cpuset;
 489
 490                 return 0;
 491         }
 492
 493         rv = cfs_quota / cfs_period;
 494
 495         /* In case quota/period does not yield a whole number, add one CPU for
 496          * the remainder.
 497          */
 498         if ((cfs_quota % cfs_period) > 0)
 499                 rv += 1;
 500
 501         nprocs = get_nprocs();
 502         if (rv > nprocs)
 503                 rv = nprocs;
 504
 505         /* use min value in cpu quota and cpuset */
 506         if (nr_cpus_in_cpuset > 0 && nr_cpus_in_cpuset < rv)
 507                 rv = nr_cpus_in_cpuset;
 508
 509         return rv;
 510 }
 511
 512 int cpuview_proc_stat(const char *cg, const char *cpuset,
 513                       struct cpuacct_usage *cg_cpu_usage, int cg_cpu_usage_size,
 514                       FILE *f, char *buf, size_t buf_size)
 515 {
 516         __do_free char *line = NULL;
 517         __do_free struct cpuacct_usage *diff = NULL;
 518         size_t linelen = 0, total_len = 0;
 519         int curcpu = -1; /* cpu numbering starts at 0 */
 520         int physcpu, i;
 521         int max_cpus = max_cpu_count(cg), cpu_cnt = 0;
 522         uint64_t user = 0, nice = 0, system = 0, idle = 0, iowait = 0, irq = 0,
 523                  softirq = 0, steal = 0, guest = 0, guest_nice = 0;
 524         uint64_t user_sum = 0, system_sum = 0, idle_sum = 0;
 525         uint64_t user_surplus = 0, system_surplus = 0;
 526         ssize_t l;
 527         uint64_t total_sum, threshold;
 528         struct cg_proc_stat *stat_node;
 529         int nprocs = get_nprocs_conf();
 530
 531         if (cg_cpu_usage_size < nprocs)
 532                 nprocs = cg_cpu_usage_size;
 533
 534         /* Read all CPU stats and stop when we've encountered other lines */
 535         while (getline(&line, &linelen, f) != -1) {
 536                 int ret;
 537                 char cpu_char[10]; /* That's a lot of cores */
 538                 uint64_t all_used, cg_used;
 539
 540                 if (strlen(line) == 0)
 541                         continue;
 542
 543                 /* not a ^cpuN line containing a number N */
 544                 if (sscanf(line, "cpu%9[^ ]", cpu_char) != 1)
 545                         break;
 546
 547                 if (sscanf(cpu_char, "%d", &physcpu) != 1)
 548                         continue;
 549
 550                 if (physcpu >= cg_cpu_usage_size)
 551                         continue;
 552
 553                 curcpu++;
 554                 cpu_cnt++;
 555
 556                 if (!cpu_in_cpuset(physcpu, cpuset)) {
 557                         for (i = curcpu; i <= physcpu; i++)
 558                                 cg_cpu_usage[i].online = false;
 559                         continue;
 560                 }
 561
 562                 if (curcpu < physcpu) {
 563                         /* Some CPUs may be disabled */
 564                         for (i = curcpu; i < physcpu; i++)
 565                                 cg_cpu_usage[i].online = false;
 566
 567                         curcpu = physcpu;
 568                 }
 569
 570                 cg_cpu_usage[curcpu].online = true;
 571
 572                 ret = sscanf(line, "%*s %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 "lu",
 573                            &user,
 574                            &nice,
 575                            &system,
 576                            &idle,
 577                            &iowait,
 578                            &irq,
 579                            &softirq,
 580                            &steal,
 581                            &guest,
 582                            &guest_nice);
 583                 if (ret != 10)
 584                         continue;
 585
 586                 all_used = user + nice + system + iowait + irq + softirq + steal + guest + guest_nice;
 587                 cg_used = cg_cpu_usage[curcpu].user + cg_cpu_usage[curcpu].system;
 588
 589                 if (all_used >= cg_used) {
 590                         cg_cpu_usage[curcpu].idle = idle + (all_used - cg_used);
 591
 592                 } else {
 593                         lxcfs_error("cpu%d from %s has unexpected cpu time: %" PRIu64 " in /proc/stat, %" PRIu64 " in cpuacct.usage_all; unable to determine idle time",
 594                                     curcpu, cg, all_used, cg_used);
 595                         cg_cpu_usage[curcpu].idle = idle;
 596                 }
 597         }
 598
 599         /* Cannot use more CPUs than is available due to cpuset */
 600         if (max_cpus > cpu_cnt)
 601                 max_cpus = cpu_cnt;
 602
 603         stat_node = find_or_create_proc_stat_node(cg_cpu_usage, nprocs, cg);
 604         if (!stat_node)
 605                 return log_error(0, "Failed to find/create stat node for %s", cg);
 606
 607         diff = malloc(sizeof(struct cpuacct_usage) * nprocs);
 608         if (!diff)
 609                 return 0;
 610
 611         /*
 612          * If the new values are LOWER than values stored in memory, it means
 613          * the cgroup has been reset/recreated and we should reset too.
 614          */
 615         for (curcpu = 0; curcpu < nprocs; curcpu++) {
 616                 if (!cg_cpu_usage[curcpu].online)
 617                         continue;
 618
 619                 if (cg_cpu_usage[curcpu].user < stat_node->usage[curcpu].user)
 620                         reset_proc_stat_node(stat_node, cg_cpu_usage, nprocs);
 621
 622                 break;
 623         }
 624
 625         total_sum = diff_cpu_usage(stat_node->usage, cg_cpu_usage, diff, nprocs);
 626
 627         for (curcpu = 0, i = -1; curcpu < nprocs; curcpu++) {
 628                 stat_node->usage[curcpu].online = cg_cpu_usage[curcpu].online;
 629
 630                 if (!stat_node->usage[curcpu].online)
 631                         continue;
 632
 633                 i++;
 634
 635                 stat_node->usage[curcpu].user += diff[curcpu].user;
 636                 stat_node->usage[curcpu].system += diff[curcpu].system;
 637                 stat_node->usage[curcpu].idle += diff[curcpu].idle;
 638
 639                 if (max_cpus > 0 && i >= max_cpus) {
 640                         user_surplus += diff[curcpu].user;
 641                         system_surplus += diff[curcpu].system;
 642                 }
 643         }
 644
 645         /* Calculate usage counters of visible CPUs */
 646         if (max_cpus > 0) {
 647                 uint64_t diff_user = 0;
 648                 uint64_t diff_system = 0;
 649                 uint64_t diff_idle = 0;
 650                 uint64_t max_diff_idle = 0;
 651                 uint64_t max_diff_idle_index = 0;
 652                 double exact_cpus;
 653
 654                 /* threshold = maximum usage per cpu, including idle */
 655                 threshold = total_sum / cpu_cnt * max_cpus;
 656
 657                 for (curcpu = 0, i = -1; curcpu < nprocs; curcpu++) {
 658                         if (!stat_node->usage[curcpu].online)
 659                                 continue;
 660
 661                         i++;
 662
 663                         if (i == max_cpus)
 664                                 break;
 665
 666                         if (diff[curcpu].user + diff[curcpu].system >= threshold)
 667                                 continue;
 668
 669                         /* Add user */
 670                         add_cpu_usage(&user_surplus, &diff[curcpu],
 671                                       &diff[curcpu].user, threshold);
 672
 673                         if (diff[curcpu].user + diff[curcpu].system >= threshold)
 674                                 continue;
 675
 676                         /* If there is still room, add system */
 677                         add_cpu_usage(&system_surplus, &diff[curcpu],
 678                                       &diff[curcpu].system, threshold);
 679                 }
 680
 681                 if (user_surplus > 0)
 682                         lxcfs_debug("leftover user: %lu for %s\n", user_surplus, cg);
 683                 if (system_surplus > 0)
 684                         lxcfs_debug("leftover system: %lu for %s\n", system_surplus, cg);
 685
 686                 for (curcpu = 0, i = -1; curcpu < nprocs; curcpu++) {
 687                         if (!stat_node->usage[curcpu].online)
 688                                 continue;
 689
 690                         i++;
 691
 692                         if (i == max_cpus)
 693                                 break;
 694
 695                         stat_node->view[curcpu].user += diff[curcpu].user;
 696                         stat_node->view[curcpu].system += diff[curcpu].system;
 697                         stat_node->view[curcpu].idle += diff[curcpu].idle;
 698
 699                         user_sum += stat_node->view[curcpu].user;
 700                         system_sum += stat_node->view[curcpu].system;
 701                         idle_sum += stat_node->view[curcpu].idle;
 702
 703                         diff_user += diff[curcpu].user;
 704                         diff_system += diff[curcpu].system;
 705                         diff_idle += diff[curcpu].idle;
 706                         if (diff[curcpu].idle > max_diff_idle) {
 707                                 max_diff_idle = diff[curcpu].idle;
 708                                 max_diff_idle_index = curcpu;
 709                         }
 710
 711                         lxcfs_v("curcpu: %d, diff_user: %lu, diff_system: %lu, diff_idle: %lu\n", curcpu, diff[curcpu].user, diff[curcpu].system, diff[curcpu].idle);
 712                 }
 713                 lxcfs_v("total. diff_user: %lu, diff_system: %lu, diff_idle: %lu\n", diff_user, diff_system, diff_idle);
 714
 715                 /* revise cpu usage view to support partial cpu case. */
 716                 exact_cpus = exact_cpu_count(cg);
 717                 if (exact_cpus < (double)max_cpus){
 718                         unsigned long delta = (unsigned long)((double)(diff_user + diff_system + diff_idle) * (1 - exact_cpus / (double)max_cpus));
 719
 720                         lxcfs_v("revising cpu usage view to match the exact cpu count [%f]\n", exact_cpus);
 721                         lxcfs_v("delta: %lu\n", delta);
 722                         lxcfs_v("idle_sum before: %lu\n", idle_sum);
 723                         idle_sum = idle_sum > delta ? idle_sum - delta : 0;
 724                         lxcfs_v("idle_sum after: %lu\n", idle_sum);
 725
 726                         curcpu = max_diff_idle_index;
 727                         lxcfs_v("curcpu: %d, idle before: %lu\n", curcpu, stat_node->view[curcpu].idle);
 728                         stat_node->view[curcpu].idle = stat_node->view[curcpu].idle > delta ? stat_node->view[curcpu].idle - delta : 0;
 729                         lxcfs_v("curcpu: %d, idle after: %lu\n", curcpu, stat_node->view[curcpu].idle);
 730                 }
 731         } else {
 732                 for (curcpu = 0; curcpu < nprocs; curcpu++) {
 733                         if (!stat_node->usage[curcpu].online)
 734                                 continue;
 735
 736                         stat_node->view[curcpu].user = stat_node->usage[curcpu].user;
 737                         stat_node->view[curcpu].system = stat_node->usage[curcpu].system;
 738                         stat_node->view[curcpu].idle = stat_node->usage[curcpu].idle;
 739
 740                         user_sum += stat_node->view[curcpu].user;
 741                         system_sum += stat_node->view[curcpu].system;
 742                         idle_sum += stat_node->view[curcpu].idle;
 743                 }
 744         }
 745
 746         /* Render the file */
 747         /* cpu-all */
 748         l = snprintf(buf, buf_size,
 749                      "cpu  %" PRIu64 " 0 %" PRIu64 " %" PRIu64 " 0 0 0 0 0 0\n",
 750                      user_sum, system_sum, idle_sum);
 751         lxcfs_v("cpu-all: %s\n", buf);
 752         if (l < 0)
 753                 return log_error(0, "Failed to write cache");
 754         if (l >= buf_size)
 755                 return log_error(0, "Write to cache was truncated");
 756
 757         buf += l;
 758         buf_size -= l;
 759         total_len += l;
 760
 761         /* Render visible CPUs */
 762         for (curcpu = 0, i = -1; curcpu < nprocs; curcpu++) {
 763                 if (!stat_node->usage[curcpu].online)
 764                         continue;
 765
 766                 i++;
 767
 768                 if (max_cpus > 0 && i == max_cpus)
 769                         break;
 770
 771                 l = snprintf(buf, buf_size, "cpu%d %" PRIu64 " 0 %" PRIu64 " %" PRIu64 " 0 0 0 0 0 0\n",
 772                              i,
 773                              stat_node->view[curcpu].user,
 774                              stat_node->view[curcpu].system,
 775                              stat_node->view[curcpu].idle);
 776                 lxcfs_v("cpu: %s\n", buf);
 777                 if (l < 0)
 778                         return log_error(0, "Failed to write cache");
 779                 if (l >= buf_size)
 780                         return log_error(0, "Write to cache was truncated");
 781
 782                 buf += l;
 783                 buf_size -= l;
 784                 total_len += l;
 785         }
 786
 787         /* Pass the rest of /proc/stat, start with the last line read */
 788         l = snprintf(buf, buf_size, "%s", line);
 789         if (l < 0)
 790                 return log_error(0, "Failed to write cache");
 791         if (l >= buf_size)
 792                 return log_error(0, "Write to cache was truncated");
 793
 794         buf += l;
 795         buf_size -= l;
 796         total_len += l;
 797
 798         /* Pass the rest of the host's /proc/stat */
 799         while (getline(&line, &linelen, f) != -1) {
 800                 l = snprintf(buf, buf_size, "%s", line);
 801                 if (l < 0)
 802                         return log_error(0, "Failed to write cache");
 803                 if (l >= buf_size)
 804                         return log_error(0, "Write to cache was truncated");
 805
 806                 buf += l;
 807                 buf_size -= l;
 808                 total_len += l;
 809         }
 810
 811         if (stat_node)
 812                 pthread_mutex_unlock(&stat_node->lock);
 813
 814         return total_len;
 815 }
 816
 817 /*
 818  * check whether this is a '^processor" line in /proc/cpuinfo
 819  */
 820 static inline bool is_processor_line(const char *line)
 821 {
 822         int cpu;
 823         return sscanf(line, "processor       : %d", &cpu) == 1;
 824 }
 825
 826 static inline bool cpuline_in_cpuset(const char *line, const char *cpuset)
 827 {
 828         int cpu;
 829
 830         if (sscanf(line, "processor       : %d", &cpu) == 1)
 831                 return cpu_in_cpuset(cpu, cpuset);
 832
 833         return false;
 834 }
 835
 836 int proc_cpuinfo_read(char *buf, size_t size, off_t offset,
 837                       struct fuse_file_info *fi)
 838 {
 839         __do_free char *cg = NULL, *cpuset = NULL, *line = NULL;
 840         __do_free void *fopen_cache = NULL;
 841         __do_fclose FILE *f = NULL;
 842         struct fuse_context *fc = fuse_get_context();
 843         struct lxcfs_opts *opts = (struct lxcfs_opts *)fc->private_data;
 844         struct file_info *d = INTTYPE_TO_PTR(fi->fh);
 845         size_t linelen = 0, total_len = 0;
 846         bool am_printing = false, firstline = true, is_s390x = false;
 847         int curcpu = -1, cpu, max_cpus = 0;
 848         bool use_view;
 849         char *cache = d->buf;
 850         size_t cache_size = d->buflen;
 851
 852         if (offset){
 853                 int left;
 854
 855                 if (offset > d->size)
 856                         return -EINVAL;
 857
 858                 if (!d->cached)
 859                         return 0;
 860
 861                 left = d->size - offset;
 862                 total_len = left > size ? size: left;
 863                 memcpy(buf, cache + offset, total_len);
 864
 865                 return total_len;
 866         }
 867
 868         pid_t initpid = lookup_initpid_in_store(fc->pid);
 869         if (initpid <= 1 || is_shared_pidns(initpid))
 870                 initpid = fc->pid;
 871
 872         cg = get_pid_cgroup(initpid, "cpuset");
 873         if (!cg)
 874                 return read_file_fuse("proc/cpuinfo", buf, size, d);
 875         prune_init_slice(cg);
 876
 877         cpuset = get_cpuset(cg);
 878         if (!cpuset)
 879                 return 0;
 880
 881         if (cgroup_ops->can_use_cpuview(cgroup_ops) && opts && opts->use_cfs)
 882                 use_view = true;
 883         else
 884                 use_view = false;
 885         if (use_view)
 886                 max_cpus = max_cpu_count(cg);
 887
 888         f = fopen_cached("/proc/cpuinfo", "re", &fopen_cache);
 889         if (!f)
 890                 return 0;
 891
 892         while (getline(&line, &linelen, f) != -1) {
 893                 ssize_t l;
 894                 if (firstline) {
 895                         firstline = false;
 896                         if (strstr(line, "IBM/S390") != NULL) {
 897                                 is_s390x = true;
 898                                 am_printing = true;
 899                                 continue;
 900                         }
 901                 }
 902
 903                 if (strncmp(line, "# processors:", 12) == 0)
 904                         continue;
 905
 906                 if (is_processor_line(line)) {
 907                         if (use_view && max_cpus > 0 && (curcpu + 1) == max_cpus)
 908                                 break;
 909
 910                         am_printing = cpuline_in_cpuset(line, cpuset);
 911                         if (am_printing) {
 912                                 curcpu++;
 913                                 l = snprintf(cache, cache_size, "processor      : %d\n", curcpu);
 914                                 if (l < 0)
 915                                         return log_error(0, "Failed to write cache");
 916                                 if (l >= cache_size)
 917                                         return log_error(0, "Write to cache was truncated");
 918                                 cache += l;
 919                                 cache_size -= l;
 920                                 total_len += l;
 921                         }
 922                         continue;
 923                 } else if (is_s390x && sscanf(line, "processor %d:", &cpu) == 1) {
 924                         char *p;
 925
 926                         if (use_view && max_cpus > 0 && (curcpu + 1) == max_cpus)
 927                                 break;
 928
 929                         if (!cpu_in_cpuset(cpu, cpuset))
 930                                 continue;
 931
 932                         curcpu ++;
 933                         p = strchr(line, ':');
 934                         if (!p || !*p)
 935                                 return 0;
 936                         p++;
 937
 938                         l = snprintf(cache, cache_size, "processor %d:%s", curcpu, p);
 939                         if (l < 0)
 940                                 return log_error(0, "Failed to write cache");
 941                         if (l >= cache_size)
 942                                 return log_error(0, "Write to cache was truncated");
 943
 944                         cache += l;
 945                         cache_size -= l;
 946                         total_len += l;
 947                         continue;
 948
 949                 }
 950                 if (am_printing) {
 951                         l = snprintf(cache, cache_size, "%s", line);
 952                         if (l < 0)
 953                                 return log_error(0, "Failed to write cache");
 954                         if (l >= cache_size)
 955                                 return log_error(0, "Write to cache was truncated");
 956
 957                         cache += l;
 958                         cache_size -= l;
 959                         total_len += l;
 960                 }
 961         }
 962
 963         if (is_s390x) {
 964                 __do_free char *origcache = d->buf;
 965                 ssize_t l;
 966
 967                 d->buf = malloc(d->buflen);
 968                 if (!d->buf) {
 969                         d->buf = move_ptr(origcache);
 970                         return 0;
 971                 }
 972
 973                 cache = d->buf;
 974                 cache_size = d->buflen;
 975                 total_len = 0;
 976                 l = snprintf(cache, cache_size, "vendor_id       : IBM/S390\n");
 977                 if (l < 0 || l >= cache_size)
 978                         return 0;
 979
 980                 cache_size -= l;
 981                 cache += l;
 982                 total_len += l;
 983                 l = snprintf(cache, cache_size, "# processors    : %d\n", curcpu + 1);
 984                 if (l < 0 || l >= cache_size)
 985                         return 0;
 986
 987                 cache_size -= l;
 988                 cache += l;
 989                 total_len += l;
 990                 l = snprintf(cache, cache_size, "%s", origcache);
 991                 if (l < 0 || l >= cache_size)
 992                         return 0;
 993                 total_len += l;
 994         }
 995
 996         d->cached = 1;
 997         d->size = total_len;
 998         if (total_len > size)
 999                 total_len = size;
1000
1001         /* read from off 0 */
1002         memcpy(buf, d->buf, total_len);
1003
1004         return total_len;
1005 }
1006
1007 /*
1008  * Returns 0 on success.
1009  * It is the caller's responsibility to free `return_usage`, unless this
1010  * function returns an error.
1011  */
1012 int read_cpuacct_usage_all(char *cg, char *cpuset,
1013                            struct cpuacct_usage **return_usage, int *size)
1014 {
1015         __do_free char *usage_str = NULL;
1016         __do_free struct cpuacct_usage *cpu_usage = NULL;
1017         int cpucount = get_nprocs_conf();
1018         int i = 0, j = 0, read_pos = 0, read_cnt = 0;
1019         int ret;
1020         int cg_cpu;
1021         uint64_t cg_user, cg_system;
1022         int64_t ticks_per_sec;
1023
1024         ticks_per_sec = sysconf(_SC_CLK_TCK);
1025
1026         if (ticks_per_sec < 0 && errno == EINVAL) {
1027                 lxcfs_v(
1028                         "%s\n",
1029                         "read_cpuacct_usage_all failed to determine number of clock ticks "
1030                         "in a second");
1031                 return -1;
1032         }
1033
1034         cpu_usage = malloc(sizeof(struct cpuacct_usage) * cpucount);
1035         if (!cpu_usage)
1036                 return -ENOMEM;
1037
1038         memset(cpu_usage, 0, sizeof(struct cpuacct_usage) * cpucount);
1039         if (!cgroup_ops->get(cgroup_ops, "cpuacct", cg, "cpuacct.usage_all", &usage_str)) {
1040                 char *data = NULL;
1041                 size_t sz = 0, asz = 0;
1042
1043                 /* read cpuacct.usage_percpu instead. */
1044                 lxcfs_v("failed to read cpuacct.usage_all. reading cpuacct.usage_percpu instead\n%s", "");
1045                 if (!cgroup_ops->get(cgroup_ops, "cpuacct", cg, "cpuacct.usage_percpu", &usage_str))
1046                         return -1;
1047                 lxcfs_v("usage_str: %s\n", usage_str);
1048
1049                 /* convert cpuacct.usage_percpu into cpuacct.usage_all. */
1050                 lxcfs_v("converting cpuacct.usage_percpu into cpuacct.usage_all\n%s", "");
1051
1052                 must_strcat(&data, &sz, &asz, "cpu user system\n");
1053
1054                 while (sscanf(usage_str + read_pos, "%" PRIu64 " %n", &cg_user, &read_cnt) > 0) {
1055                         lxcfs_debug("i: %d, cg_user: %" PRIu64 ", read_pos: %d, read_cnt: %d\n", i, cg_user, read_pos, read_cnt);
1056                         must_strcat(&data, &sz, &asz, "%d %lu 0\n", i, cg_user);
1057                         i++;
1058                         read_pos += read_cnt;
1059                 }
1060
1061                 usage_str = data;
1062
1063                 lxcfs_v("usage_str: %s\n", usage_str);
1064         }
1065
1066         if (sscanf(usage_str, "cpu user system\n%n", &read_cnt) != 0)
1067                 return log_error(-1, "read_cpuacct_usage_all reading first line from %s/cpuacct.usage_all failed", cg);
1068
1069         read_pos += read_cnt;
1070
1071         for (i = 0, j = 0; i < cpucount; i++) {
1072                 ret = sscanf(usage_str + read_pos,
1073                              "%d %" PRIu64 " %" PRIu64 "\n%n", &cg_cpu,
1074                              &cg_user, &cg_system, &read_cnt);
1075
1076                 if (ret == EOF)
1077                         break;
1078
1079                 if (ret != 3)
1080                         return log_error(-1, "read_cpuacct_usage_all reading from %s/cpuacct.usage_all failed", cg);
1081
1082                 read_pos += read_cnt;
1083
1084                 /* Convert the time from nanoseconds to USER_HZ */
1085                 cpu_usage[j].user = cg_user / 1000.0 / 1000 / 1000 * ticks_per_sec;
1086                 cpu_usage[j].system = cg_system / 1000.0 / 1000 / 1000 * ticks_per_sec;
1087                 j++;
1088         }
1089
1090         *return_usage = move_ptr(cpu_usage);
1091         *size = cpucount;
1092         return 0;
1093 }
1094
1095 static bool cpuview_init_head(struct cg_proc_stat_head **head)
1096 {
1097         *head = malloc(sizeof(struct cg_proc_stat_head));
1098         if (!(*head))
1099                 return log_error(false, "%s", strerror(errno));
1100
1101         (*head)->lastcheck = time(NULL);
1102         (*head)->next = NULL;
1103
1104         if (pthread_rwlock_init(&(*head)->lock, NULL) != 0) {
1105                 free_disarm(*head);
1106                 return log_error(false, "Failed to initialize list lock");
1107         }
1108
1109         return true;
1110 }
1111
1112 bool init_cpuview(void)
1113 {
1114         int i;
1115
1116         for (i = 0; i < CPUVIEW_HASH_SIZE; i++)
1117                 proc_stat_history[i] = NULL;
1118
1119         for (i = 0; i < CPUVIEW_HASH_SIZE; i++) {
1120                 if (!cpuview_init_head(&proc_stat_history[i]))
1121                         goto err;
1122         }
1123
1124         return true;
1125
1126 err:
1127         for (i = 0; i < CPUVIEW_HASH_SIZE; i++) {
1128                 if (proc_stat_history[i])
1129                         free_disarm(proc_stat_history[i]);
1130         }
1131
1132         return false;
1133 }
1134
1135 static void cpuview_free_head(struct cg_proc_stat_head *head)
1136 {
1137         struct cg_proc_stat *node, *tmp;
1138
1139         if (head->next) {
1140                 node = head->next;
1141
1142                 for (;;) {
1143                         tmp = node;
1144                         node = node->next;
1145                         free_proc_stat_node(tmp);
1146
1147                         if (!node)
1148                                 break;
1149                 }
1150         }
1151
1152         pthread_rwlock_destroy(&head->lock);
1153         free_disarm(head);
1154 }
1155
1156 void free_cpuview(void)
1157 {
1158         for (int i = 0; i < CPUVIEW_HASH_SIZE; i++)
1159                 if (proc_stat_history[i])
1160                         cpuview_free_head(proc_stat_history[i]);
1161 }