1 /*
   2  * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include <string.h>
  26 #include <math.h>
  27 #include <errno.h>
  28 #include "utilities/globalDefinitions.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "runtime/os.hpp"
  31 #include "logging/log.hpp"
  32 #include "osContainer_linux.hpp"
  33 
  34 /*
  35  * PER_CPU_SHARES has been set to 1024 because CPU shares' quota
  36  * is commonly used in cloud frameworks like Kubernetes[1],
  37  * AWS[2] and Mesos[3] in a similar way. They spawn containers with
  38  * --cpu-shares option values scaled by PER_CPU_SHARES. Thus, we do
  39  * the inverse for determining the number of possible available
  40  * CPUs to the JVM inside a container. See JDK-8216366.
  41  *
  42  * [1] https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/#meaning-of-cpu
  43  *     In particular:
  44  *        When using Docker:
  45  *          The spec.containers[].resources.requests.cpu is converted to its core value, which is potentially
  46  *          fractional, and multiplied by 1024. The greater of this number or 2 is used as the value of the
  47  *          --cpu-shares flag in the docker run command.
  48  * [2] https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_ContainerDefinition.html
  49  * [3] https://github.com/apache/mesos/blob/3478e344fb77d931f6122980c6e94cd3913c441d/src/docker/docker.cpp#L648
  50  *     https://github.com/apache/mesos/blob/3478e344fb77d931f6122980c6e94cd3913c441d/src/slave/containerizer/mesos/isolators/cgroups/constants.hpp#L30
  51  */
  52 #define PER_CPU_SHARES 1024
  53 
  54 bool  OSContainer::_is_initialized   = false;
  55 bool  OSContainer::_is_containerized = false;
  56 julong _unlimited_memory;
  57 
  58 class CgroupSubsystem: CHeapObj<mtInternal> {
  59  friend class OSContainer;
  60 
  61  private:
  62     /* mountinfo contents */
  63     char *_root;
  64     char *_mount_point;
  65 
  66     /* Constructed subsystem directory */
  67     char *_path;
  68 
  69  public:
  70     CgroupSubsystem(char *root, char *mountpoint) {
  71       _root = os::strdup(root);
  72       _mount_point = os::strdup(mountpoint);
  73       _path = NULL;
  74     }
  75 
  76     /*
  77      * Set directory to subsystem specific files based
  78      * on the contents of the mountinfo and cgroup files.
  79      */
  80     void set_subsystem_path(char *cgroup_path) {
  81       char buf[MAXPATHLEN+1];
  82       if (_root != NULL && cgroup_path != NULL) {
  83         if (strcmp(_root, "/") == 0) {
  84           int buflen;
  85           strncpy(buf, _mount_point, MAXPATHLEN);
  86           buf[MAXPATHLEN-1] = '\0';
  87           if (strcmp(cgroup_path,"/") != 0) {
  88             buflen = strlen(buf);
  89             if ((buflen + strlen(cgroup_path)) > (MAXPATHLEN-1)) {
  90               return;
  91             }
  92             strncat(buf, cgroup_path, MAXPATHLEN-buflen);
  93             buf[MAXPATHLEN-1] = '\0';
  94           }
  95           _path = os::strdup(buf);
  96         } else {
  97           if (strcmp(_root, cgroup_path) == 0) {
  98             strncpy(buf, _mount_point, MAXPATHLEN);
  99             buf[MAXPATHLEN-1] = '\0';
 100             _path = os::strdup(buf);
 101           } else {
 102             char *p = strstr(cgroup_path, _root);
 103             if (p != NULL && p == _root) {
 104               if (strlen(cgroup_path) > strlen(_root)) {
 105                 int buflen;
 106                 strncpy(buf, _mount_point, MAXPATHLEN);
 107                 buf[MAXPATHLEN-1] = '\0';
 108                 buflen = strlen(buf);
 109                 if ((buflen + strlen(cgroup_path) - strlen(_root)) > (MAXPATHLEN-1)) {
 110                   return;
 111                 }
 112                 strncat(buf, cgroup_path + strlen(_root), MAXPATHLEN-buflen);
 113                 buf[MAXPATHLEN-1] = '\0';
 114                 _path = os::strdup(buf);
 115               }
 116             }
 117           }
 118         }
 119       }
 120     }
 121 
 122     char *subsystem_path() { return _path; }
 123 };
 124 
 125 class CgroupMemorySubsystem: CgroupSubsystem {
 126  friend class OSContainer;
 127 
 128  private:
 129     /* Some container runtimes set limits via cgroup
 130      * hierarchy. If set to true consider also memory.stat
 131      * file if everything else seems unlimited */
 132     bool _uses_mem_hierarchy;
 133 
 134  public:
 135     CgroupMemorySubsystem(char *root, char *mountpoint) : CgroupSubsystem::CgroupSubsystem(root, mountpoint) {
 136       _uses_mem_hierarchy = false;
 137     }
 138 
 139     bool is_hierarchical() { return _uses_mem_hierarchy; }
 140     void set_hierarchical(bool value) { _uses_mem_hierarchy = value; }
 141 };
 142 
 143 CgroupMemorySubsystem* memory = NULL;
 144 CgroupSubsystem* cpuset = NULL;
 145 CgroupSubsystem* cpu = NULL;
 146 CgroupSubsystem* cpuacct = NULL;
 147 
 148 typedef char * cptr;
 149 
 150 PRAGMA_DIAG_PUSH
 151 PRAGMA_FORMAT_NONLITERAL_IGNORED
 152 template <typename T> int subsystem_file_line_contents(CgroupSubsystem* c,
 153                                               const char *filename,
 154                                               const char *matchline,
 155                                               const char *scan_fmt,
 156                                               T returnval) {
 157   FILE *fp = NULL;
 158   char *p;
 159   char file[MAXPATHLEN+1];
 160   char buf[MAXPATHLEN+1];
 161   char discard[MAXPATHLEN+1];
 162   bool found_match = false;
 163 
 164   if (c == NULL) {
 165     log_debug(os, container)("subsystem_file_line_contents: CgroupSubsytem* is NULL");
 166     return OSCONTAINER_ERROR;
 167   }
 168   if (c->subsystem_path() == NULL) {
 169     log_debug(os, container)("subsystem_file_line_contents: subsystem path is NULL");
 170     return OSCONTAINER_ERROR;
 171   }
 172 
 173   strncpy(file, c->subsystem_path(), MAXPATHLEN);
 174   file[MAXPATHLEN-1] = '\0';
 175   int filelen = strlen(file);
 176   if ((filelen + strlen(filename)) > (MAXPATHLEN-1)) {
 177     log_debug(os, container)("File path too long %s, %s", file, filename);
 178     return OSCONTAINER_ERROR;
 179   }
 180   strncat(file, filename, MAXPATHLEN-filelen);
 181   log_trace(os, container)("Path to %s is %s", filename, file);
 182   fp = fopen(file, "r");
 183   if (fp != NULL) {
 184     int err = 0;
 185     while ((p = fgets(buf, MAXPATHLEN, fp)) != NULL) {
 186       found_match = false;
 187       if (matchline == NULL) {
 188         // single-line file case
 189         int matched = sscanf(p, scan_fmt, returnval);
 190         found_match = (matched == 1);
 191       } else {
 192         // multi-line file case
 193         if (strstr(p, matchline) != NULL) {
 194           // discard matchline string prefix
 195           int matched = sscanf(p, scan_fmt, discard, returnval);
 196           found_match = (matched == 2);
 197         } else {
 198           continue; // substring not found
 199         }
 200       }
 201       if (found_match) {
 202         fclose(fp);
 203         return 0;
 204       } else {
 205         err = 1;
 206         log_debug(os, container)("Type %s not found in file %s", scan_fmt, file);
 207       }
 208     }
 209     if (err == 0) {
 210       log_debug(os, container)("Empty file %s", file);
 211     }
 212   } else {
 213     log_debug(os, container)("Open of file %s failed, %s", file, os::strerror(errno));
 214   }
 215   if (fp != NULL)
 216     fclose(fp);
 217   return OSCONTAINER_ERROR;
 218 }
 219 PRAGMA_DIAG_POP
 220 
 221 #define GET_CONTAINER_INFO(return_type, subsystem, filename,              \
 222                            logstring, scan_fmt, variable)                 \
 223   return_type variable;                                                   \
 224 {                                                                         \
 225   int err;                                                                \
 226   err = subsystem_file_line_contents(subsystem,                           \
 227                                      filename,                            \
 228                                      NULL,                                \
 229                                      scan_fmt,                            \
 230                                      &variable);                          \
 231   if (err != 0)                                                           \
 232     return (return_type) OSCONTAINER_ERROR;                               \
 233                                                                           \
 234   log_trace(os, container)(logstring, variable);                          \
 235 }
 236 
 237 #define GET_CONTAINER_INFO_CPTR(return_type, subsystem, filename,         \
 238                                logstring, scan_fmt, variable, bufsize)    \
 239   char variable[bufsize];                                                 \
 240 {                                                                         \
 241   int err;                                                                \
 242   err = subsystem_file_line_contents(subsystem,                           \
 243                                      filename,                            \
 244                                      NULL,                                \
 245                                      scan_fmt,                            \
 246                                      variable);                           \
 247   if (err != 0)                                                           \
 248     return (return_type) NULL;                                            \
 249                                                                           \
 250   log_trace(os, container)(logstring, variable);                          \
 251 }
 252 
 253 #define GET_CONTAINER_INFO_LINE(return_type, subsystem, filename,         \
 254                            matchline, logstring, scan_fmt, variable)      \
 255   return_type variable;                                                   \
 256 {                                                                         \
 257   int err;                                                                \
 258   err = subsystem_file_line_contents(subsystem,                           \
 259                                 filename,                                 \
 260                                 matchline,                                \
 261                                 scan_fmt,                                 \
 262                                 &variable);                               \
 263   if (err != 0)                                                           \
 264     return (return_type) OSCONTAINER_ERROR;                               \
 265                                                                           \
 266   log_trace(os, container)(logstring, variable);                          \
 267 }
 268 
 269 /* init
 270  *
 271  * Initialize the container support and determine if
 272  * we are running under cgroup control.
 273  */
 274 void OSContainer::init() {
 275   FILE *mntinfo = NULL;
 276   FILE *cgroup = NULL;
 277   char buf[MAXPATHLEN+1];
 278   char tmproot[MAXPATHLEN+1];
 279   char tmpmount[MAXPATHLEN+1];
 280   char *p;
 281   jlong mem_limit;
 282 
 283   assert(!_is_initialized, "Initializing OSContainer more than once");
 284 
 285   _is_initialized = true;
 286   _is_containerized = false;
 287 
 288   _unlimited_memory = (LONG_MAX / os::vm_page_size()) * os::vm_page_size();
 289 
 290   log_trace(os, container)("OSContainer::init: Initializing Container Support");
 291   if (!UseContainerSupport) {
 292     log_trace(os, container)("Container Support not enabled");
 293     return;
 294   }
 295 
 296   /*
 297    * Find the cgroup mount point for memory and cpuset
 298    * by reading /proc/self/mountinfo
 299    *
 300    * Example for docker:
 301    * 219 214 0:29 /docker/7208cebd00fa5f2e342b1094f7bed87fa25661471a4637118e65f1c995be8a34 /sys/fs/cgroup/memory ro,nosuid,nodev,noexec,relatime - cgroup cgroup rw,memory
 302    *
 303    * Example for host:
 304    * 34 28 0:29 / /sys/fs/cgroup/memory rw,nosuid,nodev,noexec,relatime shared:16 - cgroup cgroup rw,memory
 305    */
 306   mntinfo = fopen("/proc/self/mountinfo", "r");
 307   if (mntinfo == NULL) {
 308       log_debug(os, container)("Can't open /proc/self/mountinfo, %s",
 309                                os::strerror(errno));
 310       return;
 311   }
 312 
 313   while ((p = fgets(buf, MAXPATHLEN, mntinfo)) != NULL) {
 314     char tmpcgroups[MAXPATHLEN+1];
 315     char *cptr = tmpcgroups;
 316     char *token;
 317 
 318     // mountinfo format is documented at https://www.kernel.org/doc/Documentation/filesystems/proc.txt
 319     if (sscanf(p, "%*d %*d %*d:%*d %s %s %*[^-]- cgroup %*s %s", tmproot, tmpmount, tmpcgroups) != 3) {
 320       continue;
 321     }
 322     while ((token = strsep(&cptr, ",")) != NULL) {
 323       if (strcmp(token, "memory") == 0) {
 324         memory = new CgroupMemorySubsystem(tmproot, tmpmount);
 325       } else if (strcmp(token, "cpuset") == 0) {
 326         cpuset = new CgroupSubsystem(tmproot, tmpmount);
 327       } else if (strcmp(token, "cpu") == 0) {
 328         cpu = new CgroupSubsystem(tmproot, tmpmount);
 329       } else if (strcmp(token, "cpuacct") == 0) {
 330         cpuacct= new CgroupSubsystem(tmproot, tmpmount);
 331       }
 332     }
 333   }
 334 
 335   fclose(mntinfo);
 336 
 337   if (memory == NULL) {
 338     log_debug(os, container)("Required cgroup memory subsystem not found");
 339     return;
 340   }
 341   if (cpuset == NULL) {
 342     log_debug(os, container)("Required cgroup cpuset subsystem not found");
 343     return;
 344   }
 345   if (cpu == NULL) {
 346     log_debug(os, container)("Required cgroup cpu subsystem not found");
 347     return;
 348   }
 349   if (cpuacct == NULL) {
 350     log_debug(os, container)("Required cgroup cpuacct subsystem not found");
 351     return;
 352   }
 353 
 354   /*
 355    * Read /proc/self/cgroup and map host mount point to
 356    * local one via /proc/self/mountinfo content above
 357    *
 358    * Docker example:
 359    * 5:memory:/docker/6558aed8fc662b194323ceab5b964f69cf36b3e8af877a14b80256e93aecb044
 360    *
 361    * Host example:
 362    * 5:memory:/user.slice
 363    *
 364    * Construct a path to the process specific memory and cpuset
 365    * cgroup directory.
 366    *
 367    * For a container running under Docker from memory example above
 368    * the paths would be:
 369    *
 370    * /sys/fs/cgroup/memory
 371    *
 372    * For a Host from memory example above the path would be:
 373    *
 374    * /sys/fs/cgroup/memory/user.slice
 375    *
 376    */
 377   cgroup = fopen("/proc/self/cgroup", "r");
 378   if (cgroup == NULL) {
 379     log_debug(os, container)("Can't open /proc/self/cgroup, %s",
 380                              os::strerror(errno));
 381     return;
 382   }
 383 
 384   while ((p = fgets(buf, MAXPATHLEN, cgroup)) != NULL) {
 385     char *controllers;
 386     char *token;
 387     char *base;
 388 
 389     /* Skip cgroup number */
 390     strsep(&p, ":");
 391     /* Get controllers and base */
 392     controllers = strsep(&p, ":");
 393     base = strsep(&p, "\n");
 394 
 395     if (controllers == NULL) {
 396       continue;
 397     }
 398 
 399     while ((token = strsep(&controllers, ",")) != NULL) {
 400       if (strcmp(token, "memory") == 0) {
 401         memory->set_subsystem_path(base);
 402         jlong hierarchy = uses_mem_hierarchy();
 403         if (hierarchy > 0) {
 404           memory->set_hierarchical(true);
 405         }
 406       } else if (strcmp(token, "cpuset") == 0) {
 407         cpuset->set_subsystem_path(base);
 408       } else if (strcmp(token, "cpu") == 0) {
 409         cpu->set_subsystem_path(base);
 410       } else if (strcmp(token, "cpuacct") == 0) {
 411         cpuacct->set_subsystem_path(base);
 412       }
 413     }
 414   }
 415 
 416   fclose(cgroup);
 417 
 418   // We need to update the amount of physical memory now that
 419   // command line arguments have been processed.
 420   if ((mem_limit = memory_limit_in_bytes()) > 0) {
 421     os::Linux::set_physical_memory(mem_limit);
 422     log_info(os, container)("Memory Limit is: " JLONG_FORMAT, mem_limit);
 423   }
 424 
 425   _is_containerized = true;
 426 
 427 }
 428 
 429 const char * OSContainer::container_type() {
 430   if (is_containerized()) {
 431     return "cgroupv1";
 432   } else {
 433     return NULL;
 434   }
 435 }
 436 
 437 /* uses_mem_hierarchy
 438  *
 439  * Return whether or not hierarchical cgroup accounting is being
 440  * done.
 441  *
 442  * return:
 443  *    A number > 0 if true, or
 444  *    OSCONTAINER_ERROR for not supported
 445  */
 446 jlong OSContainer::uses_mem_hierarchy() {
 447   GET_CONTAINER_INFO(jlong, memory, "/memory.use_hierarchy",
 448                     "Use Hierarchy is: " JLONG_FORMAT, JLONG_FORMAT, use_hierarchy);
 449   return use_hierarchy;
 450 }
 451 
 452 
 453 /* memory_limit_in_bytes
 454  *
 455  * Return the limit of available memory for this process.
 456  *
 457  * return:
 458  *    memory limit in bytes or
 459  *    -1 for unlimited
 460  *    OSCONTAINER_ERROR for not supported
 461  */
 462 jlong OSContainer::memory_limit_in_bytes() {
 463   GET_CONTAINER_INFO(julong, memory, "/memory.limit_in_bytes",
 464                      "Memory Limit is: " JULONG_FORMAT, JULONG_FORMAT, memlimit);
 465 
 466   if (memlimit >= _unlimited_memory) {
 467     log_trace(os, container)("Non-Hierarchical Memory Limit is: Unlimited");
 468     if (memory->is_hierarchical()) {
 469       const char* matchline = "hierarchical_memory_limit";
 470       char* format = "%s " JULONG_FORMAT;
 471       GET_CONTAINER_INFO_LINE(julong, memory, "/memory.stat", matchline,
 472                              "Hierarchical Memory Limit is: " JULONG_FORMAT, format, hier_memlimit)
 473       if (hier_memlimit >= _unlimited_memory) {
 474         log_trace(os, container)("Hierarchical Memory Limit is: Unlimited");
 475       } else {
 476         return (jlong)hier_memlimit;
 477       }
 478     }
 479     return (jlong)-1;
 480   }
 481   else {
 482     return (jlong)memlimit;
 483   }
 484 }
 485 
 486 jlong OSContainer::memory_and_swap_limit_in_bytes() {
 487   GET_CONTAINER_INFO(julong, memory, "/memory.memsw.limit_in_bytes",
 488                      "Memory and Swap Limit is: " JULONG_FORMAT, JULONG_FORMAT, memswlimit);
 489   if (memswlimit >= _unlimited_memory) {
 490     log_trace(os, container)("Non-Hierarchical Memory and Swap Limit is: Unlimited");
 491     if (memory->is_hierarchical()) {
 492       const char* matchline = "hierarchical_memsw_limit";
 493       char* format = "%s " JULONG_FORMAT;
 494       GET_CONTAINER_INFO_LINE(julong, memory, "/memory.stat", matchline,
 495                              "Hierarchical Memory and Swap Limit is : " JULONG_FORMAT, format, hier_memlimit)
 496       if (hier_memlimit >= _unlimited_memory) {
 497         log_trace(os, container)("Hierarchical Memory and Swap Limit is: Unlimited");
 498       } else {
 499         return (jlong)hier_memlimit;
 500       }
 501     }
 502     return (jlong)-1;
 503   } else {
 504     return (jlong)memswlimit;
 505   }
 506 }
 507 
 508 jlong OSContainer::memory_soft_limit_in_bytes() {
 509   GET_CONTAINER_INFO(julong, memory, "/memory.soft_limit_in_bytes",
 510                      "Memory Soft Limit is: " JULONG_FORMAT, JULONG_FORMAT, memsoftlimit);
 511   if (memsoftlimit >= _unlimited_memory) {
 512     log_trace(os, container)("Memory Soft Limit is: Unlimited");
 513     return (jlong)-1;
 514   } else {
 515     return (jlong)memsoftlimit;
 516   }
 517 }
 518 
 519 /* memory_usage_in_bytes
 520  *
 521  * Return the amount of used memory for this process.
 522  *
 523  * return:
 524  *    memory usage in bytes or
 525  *    -1 for unlimited
 526  *    OSCONTAINER_ERROR for not supported
 527  */
 528 jlong OSContainer::memory_usage_in_bytes() {
 529   GET_CONTAINER_INFO(jlong, memory, "/memory.usage_in_bytes",
 530                      "Memory Usage is: " JLONG_FORMAT, JLONG_FORMAT, memusage);
 531   return memusage;
 532 }
 533 
 534 /* memory_max_usage_in_bytes
 535  *
 536  * Return the maximum amount of used memory for this process.
 537  *
 538  * return:
 539  *    max memory usage in bytes or
 540  *    OSCONTAINER_ERROR for not supported
 541  */
 542 jlong OSContainer::memory_max_usage_in_bytes() {
 543   GET_CONTAINER_INFO(jlong, memory, "/memory.max_usage_in_bytes",
 544                      "Maximum Memory Usage is: " JLONG_FORMAT, JLONG_FORMAT, memmaxusage);
 545   return memmaxusage;
 546 }
 547 
 548 /* active_processor_count
 549  *
 550  * Calculate an appropriate number of active processors for the
 551  * VM to use based on these three inputs.
 552  *
 553  * cpu affinity
 554  * cgroup cpu quota & cpu period
 555  * cgroup cpu shares
 556  *
 557  * Algorithm:
 558  *
 559  * Determine the number of available CPUs from sched_getaffinity
 560  *
 561  * If user specified a quota (quota != -1), calculate the number of
 562  * required CPUs by dividing quota by period.
 563  *
 564  * If shares are in effect (shares != -1), calculate the number
 565  * of CPUs required for the shares by dividing the share value
 566  * by PER_CPU_SHARES.
 567  *
 568  * All results of division are rounded up to the next whole number.
 569  *
 570  * If neither shares or quotas have been specified, return the
 571  * number of active processors in the system.
 572  *
 573  * If both shares and quotas have been specified, the results are
 574  * based on the flag PreferContainerQuotaForCPUCount.  If true,
 575  * return the quota value.  If false return the smallest value
 576  * between shares or quotas.
 577  *
 578  * If shares and/or quotas have been specified, the resulting number
 579  * returned will never exceed the number of active processors.
 580  *
 581  * return:
 582  *    number of CPUs
 583  */
 584 int OSContainer::active_processor_count() {
 585   int quota_count = 0, share_count = 0;
 586   int cpu_count, limit_count;
 587   int result;
 588 
 589   cpu_count = limit_count = os::Linux::active_processor_count();
 590   int quota  = cpu_quota();
 591   int period = cpu_period();
 592   int share  = cpu_shares();
 593 
 594   if (quota > -1 && period > 0) {
 595     quota_count = ceilf((float)quota / (float)period);
 596     log_trace(os, container)("CPU Quota count based on quota/period: %d", quota_count);
 597   }
 598   if (share > -1) {
 599     share_count = ceilf((float)share / (float)PER_CPU_SHARES);
 600     log_trace(os, container)("CPU Share count based on shares: %d", share_count);
 601   }
 602 
 603   // If both shares and quotas are setup results depend
 604   // on flag PreferContainerQuotaForCPUCount.
 605   // If true, limit CPU count to quota
 606   // If false, use minimum of shares and quotas
 607   if (quota_count !=0 && share_count != 0) {
 608     if (PreferContainerQuotaForCPUCount) {
 609       limit_count = quota_count;
 610     } else {
 611       limit_count = MIN2(quota_count, share_count);
 612     }
 613   } else if (quota_count != 0) {
 614     limit_count = quota_count;
 615   } else if (share_count != 0) {
 616     limit_count = share_count;
 617   }
 618 
 619   result = MIN2(cpu_count, limit_count);
 620   log_trace(os, container)("OSContainer::active_processor_count: %d", result);
 621   return result;
 622 }
 623 
 624 char * OSContainer::cpu_cpuset_cpus() {
 625   GET_CONTAINER_INFO_CPTR(cptr, cpuset, "/cpuset.cpus",
 626                      "cpuset.cpus is: %s", "%1023s", cpus, 1024);
 627   return os::strdup(cpus);
 628 }
 629 
 630 char * OSContainer::cpu_cpuset_memory_nodes() {
 631   GET_CONTAINER_INFO_CPTR(cptr, cpuset, "/cpuset.mems",
 632                      "cpuset.mems is: %s", "%1023s", mems, 1024);
 633   return os::strdup(mems);
 634 }
 635 
 636 /* cpu_quota
 637  *
 638  * Return the number of milliseconds per period
 639  * process is guaranteed to run.
 640  *
 641  * return:
 642  *    quota time in milliseconds
 643  *    -1 for no quota
 644  *    OSCONTAINER_ERROR for not supported
 645  */
 646 int OSContainer::cpu_quota() {
 647   GET_CONTAINER_INFO(int, cpu, "/cpu.cfs_quota_us",
 648                      "CPU Quota is: %d", "%d", quota);
 649   return quota;
 650 }
 651 
 652 int OSContainer::cpu_period() {
 653   GET_CONTAINER_INFO(int, cpu, "/cpu.cfs_period_us",
 654                      "CPU Period is: %d", "%d", period);
 655   return period;
 656 }
 657 
 658 /* cpu_shares
 659  *
 660  * Return the amount of cpu shares available to the process
 661  *
 662  * return:
 663  *    Share number (typically a number relative to 1024)
 664  *                 (2048 typically expresses 2 CPUs worth of processing)
 665  *    -1 for no share setup
 666  *    OSCONTAINER_ERROR for not supported
 667  */
 668 int OSContainer::cpu_shares() {
 669   GET_CONTAINER_INFO(int, cpu, "/cpu.shares",
 670                      "CPU Shares is: %d", "%d", shares);
 671   // Convert 1024 to no shares setup
 672   if (shares == 1024) return -1;
 673 
 674   return shares;
 675 }
 676