sysdeps/unix/sysv/linux/tst-skeleton-thread-affinity.c

   1 /* Generic test for CPU affinity functions, multi-threaded variant.
   2    Copyright (C) 2015-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* Before including this file, a test has to declare the helper
  20    getaffinity and setaffinity functions described in
  21    tst-skeleton-affinity.c, which is included below.  */
  22
  23 #include <errno.h>
  24 #include <pthread.h>
  25 #include <stdbool.h>
  26 #include <stdlib.h>
  27 #include <sys/time.h>
  28
  29 struct conf;
  30 static bool early_test (struct conf *);
  31
  32 /* Arbitrary run time for each pass.  */
  33 #define PASS_TIMEOUT 2
  34
  35 /* There are two passes (one with sched_yield, one without), and we
  36    double the timeout to be on the safe side.  */
  37 #define TIMEOUT (2 * PASS_TIMEOUT * 2)
  38
  39 #include "tst-skeleton-affinity.c"
  40
  41 /* 0 if still running, 1 of stopping requested.  */
  42 static int still_running;
  43
  44 /* 0 if no scheduling failures, 1 if failures are encountered.  */
  45 static int failed;
  46
  47 static void *
  48 thread_burn_one_cpu (void *closure)
  49 {
  50   int cpu = (uintptr_t) closure;
  51   while (__atomic_load_n (&still_running, __ATOMIC_RELAXED) == 0)
  52     {
  53       int current = sched_getcpu ();
  54       if (sched_getcpu () != cpu)
  55         {
  56           printf ("error: Pinned thread %d ran on impossible cpu %d\n",
  57                   cpu, current);
  58           __atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
  59           /* Terminate early.  */
  60           __atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
  61         }
  62     }
  63   return NULL;
  64 }
  65
  66 struct burn_thread
  67 {
  68   pthread_t self;
  69   struct conf *conf;
  70   cpu_set_t *initial_set;
  71   cpu_set_t *seen_set;
  72   int thread;
  73 };
  74
  75 static void *
  76 thread_burn_any_cpu (void *closure)
  77 {
  78   struct burn_thread *param = closure;
  79
  80   /* Schedule this thread around a bit to see if it lands on another
  81      CPU.  Run this for 2 seconds, once with sched_yield, once
  82      without.  */
  83   for (int pass = 1; pass <= 2; ++pass)
  84     {
  85       time_t start = time (NULL);
  86       while (time (NULL) - start <= PASS_TIMEOUT)
  87         {
  88           int cpu = sched_getcpu ();
  89           if (cpu > param->conf->last_cpu
  90               || !CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
  91                                param->initial_set))
  92             {
  93               printf ("error: Unpinned thread %d ran on impossible CPU %d\n",
  94                       param->thread, cpu);
  95               __atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
  96               return NULL;
  97             }
  98           CPU_SET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
  99                      param->seen_set);
 100           if (pass == 1)
 101             sched_yield ();
 102         }
 103     }
 104   return NULL;
 105 }
 106
 107 static void
 108 stop_and_join_threads (struct conf *conf, cpu_set_t *set,
 109                        pthread_t *pinned_first, pthread_t *pinned_last,
 110                        struct burn_thread *other_first,
 111                        struct burn_thread *other_last)
 112 {
 113   __atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
 114   for (pthread_t *p = pinned_first; p < pinned_last; ++p)
 115     {
 116       int cpu = p - pinned_first;
 117       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
 118         continue;
 119
 120       int ret = pthread_join (*p, NULL);
 121       if (ret != 0)
 122         {
 123           printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
 124           fflush (stdout);
 125           /* Cannot shut down cleanly with threads still running.  */
 126           abort ();
 127         }
 128     }
 129
 130   for (struct burn_thread *p = other_first; p < other_last; ++p)
 131     {
 132       int cpu = p - other_first;
 133       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
 134         continue;
 135
 136       int ret = pthread_join (p->self, NULL);
 137       if (ret != 0)
 138         {
 139           printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
 140           fflush (stdout);
 141           /* Cannot shut down cleanly with threads still running.  */
 142           abort ();
 143         }
 144     }
 145 }
 146
 147 /* Tries to check that the initial set of CPUs is complete and that
 148    the main thread will not run on any other threads.  */
 149 static bool
 150 early_test (struct conf *conf)
 151 {
 152   pthread_t *pinned_threads
 153     = calloc (conf->last_cpu + 1, sizeof (*pinned_threads));
 154   struct burn_thread *other_threads
 155     = calloc (conf->last_cpu + 1, sizeof (*other_threads));
 156   cpu_set_t *initial_set = CPU_ALLOC (conf->set_size);
 157   cpu_set_t *scratch_set = CPU_ALLOC (conf->set_size);
 158
 159   if (pinned_threads == NULL || other_threads == NULL
 160       || initial_set == NULL || scratch_set == NULL)
 161     {
 162       puts ("error: Memory allocation failure");
 163       return false;
 164     }
 165   if (getaffinity (CPU_ALLOC_SIZE (conf->set_size), initial_set) < 0)
 166     {
 167       printf ("error: pthread_getaffinity_np failed: %m\n");
 168       return false;
 169     }
 170   for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
 171     {
 172       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
 173         continue;
 174       other_threads[cpu].conf = conf;
 175       other_threads[cpu].initial_set = initial_set;
 176       other_threads[cpu].thread = cpu;
 177       other_threads[cpu].seen_set = CPU_ALLOC (conf->set_size);
 178       if (other_threads[cpu].seen_set == NULL)
 179         {
 180           puts ("error: Memory allocation failure");
 181           return false;
 182         }
 183       CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size),
 184                   other_threads[cpu].seen_set);
 185     }
 186
 187   pthread_attr_t attr;
 188   int ret = pthread_attr_init (&attr);
 189   if (ret != 0)
 190     {
 191       printf ("error: pthread_attr_init failed: %s\n", strerror (ret));
 192       return false;
 193     }
 194
 195   /* Spawn a thread pinned to each available CPU.  */
 196   for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
 197     {
 198       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
 199         continue;
 200       CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
 201       CPU_SET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
 202       ret = pthread_attr_setaffinity_np
 203         (&attr, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
 204       if (ret != 0)
 205         {
 206           printf ("error: pthread_attr_setaffinity_np for CPU %d failed: %s\n",
 207                   cpu, strerror (ret));
 208           stop_and_join_threads (conf, initial_set,
 209                                  pinned_threads, pinned_threads + cpu,
 210                                  NULL, NULL);
 211           return false;
 212         }
 213       ret = pthread_create (pinned_threads + cpu, &attr,
 214                             thread_burn_one_cpu, (void *) (uintptr_t) cpu);
 215       if (ret != 0)
 216         {
 217           printf ("error: pthread_create for CPU %d failed: %s\n",
 218                   cpu, strerror (ret));
 219           stop_and_join_threads (conf, initial_set,
 220                                  pinned_threads, pinned_threads + cpu,
 221                                  NULL, NULL);
 222           return false;
 223         }
 224     }
 225
 226   /* Spawn another set of threads running on all CPUs.  */
 227   for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
 228     {
 229       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
 230         continue;
 231       ret = pthread_create (&other_threads[cpu].self, NULL,
 232                             thread_burn_any_cpu, other_threads + cpu);
 233       if (ret != 0)
 234         {
 235           printf ("error: pthread_create for thread %d failed: %s\n",
 236                   cpu, strerror (ret));
 237           stop_and_join_threads (conf, initial_set,
 238                                  pinned_threads,
 239                                  pinned_threads + conf->last_cpu + 1,
 240                                  other_threads, other_threads + cpu);
 241           return false;
 242         }
 243     }
 244
 245   /* Main thread.  */
 246   struct burn_thread main_thread;
 247   main_thread.conf = conf;
 248   main_thread.initial_set = initial_set;
 249   main_thread.seen_set = scratch_set;
 250   main_thread.thread = -1;
 251   CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), main_thread.seen_set);
 252   thread_burn_any_cpu (&main_thread);
 253   stop_and_join_threads (conf, initial_set,
 254                          pinned_threads,
 255                          pinned_threads + conf->last_cpu + 1,
 256                          other_threads, other_threads + conf->last_cpu + 1);
 257
 258   printf ("info: Main thread ran on %d CPU(s) of %d available CPU(s)\n",
 259           CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set),
 260           CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), initial_set));
 261   CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
 262   for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
 263     {
 264       if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
 265         continue;
 266       CPU_OR_S (CPU_ALLOC_SIZE (conf->set_size),
 267                 scratch_set, scratch_set, other_threads[cpu].seen_set);
 268       CPU_FREE (other_threads[cpu].seen_set);
 269     }
 270   printf ("info: Other threads ran on %d CPU(s)\n",
 271           CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set));;
 272
 273
 274   pthread_attr_destroy (&attr);
 275   CPU_FREE (scratch_set);
 276   CPU_FREE (initial_set);
 277   free (pinned_threads);
 278   free (other_threads);
 279   return failed == 0;
 280 }