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

   1 /* Generic test case for CPU affinity functions.
   2    Copyright (C) 2015-2017 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 /* This file is included by the tst-affinity*.c files to test the two
  20    variants of the functions, under different conditions.  The
  21    following functions have to be definied:
  22
  23    static int getaffinity (size_t, cpu_set_t *);
  24    static int setaffinity (size_t, const cpu_set_t *);
  25    static bool early_test (struct conf *);
  26
  27    The first two functions shall affect the affinity mask for the
  28    current thread and return 0 for success, -1 for error (with an
  29    error code in errno).
  30
  31    early_test is invoked before the tests in this file affect the
  32    affinity masks.  If it returns true, testing continues, otherwise
  33    no more tests run and the overall test exits with status 1.
  34 */
  35
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <sched.h>
  39 #include <stdbool.h>
  40 #include <stdio.h>
  41
  42 /* CPU set configuration determined.  Can be used from early_test.  */
  43 struct conf
  44 {
  45   int set_size;                 /* in bits */
  46   int last_cpu;
  47 };
  48
  49 static int
  50 find_set_size (void)
  51 {
  52   /* There is considerable controversy about how to determine the size
  53      of the kernel CPU mask.  The probing loop below is only intended
  54      for testing purposes.  */
  55   for (int num_cpus = 64; num_cpus <= INT_MAX / 2; ++num_cpus)
  56     {
  57       cpu_set_t *set = CPU_ALLOC (num_cpus);
  58       size_t size = CPU_ALLOC_SIZE (num_cpus);
  59
  60       if (set == NULL)
  61         {
  62           printf ("error: CPU_ALLOC (%d) failed\n", num_cpus);
  63           return -1;
  64         }
  65       if (getaffinity (size, set) == 0)
  66         {
  67           CPU_FREE (set);
  68           return num_cpus;
  69         }
  70       if (errno != EINVAL)
  71         {
  72           printf ("error: getaffinity for %d CPUs: %m\n", num_cpus);
  73           CPU_FREE (set);
  74           return -1;
  75         }
  76       CPU_FREE (set);
  77     }
  78   puts ("error: Cannot find maximum CPU number");
  79   return -1;
  80 }
  81
  82 static int
  83 find_last_cpu (const cpu_set_t *set, size_t size)
  84 {
  85   /* We need to determine the set size with CPU_COUNT_S and the
  86      cpus_found counter because there is no direct way to obtain the
  87      actual CPU set size, in bits, from the value of
  88      CPU_ALLOC_SIZE.  */
  89   size_t cpus_found = 0;
  90   size_t total_cpus = CPU_COUNT_S (size, set);
  91   int last_cpu = -1;
  92
  93   for (int cpu = 0; cpus_found < total_cpus; ++cpu)
  94     {
  95       if (CPU_ISSET_S (cpu, size, set))
  96         {
  97           last_cpu = cpu;
  98           ++cpus_found;
  99         }
 100     }
 101   return last_cpu;
 102 }
 103
 104 static void
 105 setup_conf (struct conf *conf)
 106 {
 107   *conf = (struct conf) {-1, -1};
 108   conf->set_size = find_set_size ();
 109   if (conf->set_size > 0)
 110     {
 111       cpu_set_t *set = CPU_ALLOC (conf->set_size);
 112
 113       if (set == NULL)
 114         {
 115           printf ("error: CPU_ALLOC (%d) failed\n", conf->set_size);
 116           CPU_FREE (set);
 117           return;
 118         }
 119       if (getaffinity (CPU_ALLOC_SIZE (conf->set_size), set) < 0)
 120         {
 121           printf ("error: getaffinity failed: %m\n");
 122           CPU_FREE (set);
 123           return;
 124         }
 125       conf->last_cpu = find_last_cpu (set, CPU_ALLOC_SIZE (conf->set_size));
 126       if (conf->last_cpu < 0)
 127         puts ("info: No test CPU found");
 128       CPU_FREE (set);
 129     }
 130 }
 131
 132 static bool
 133 test_size (const struct conf *conf, size_t size)
 134 {
 135   if (size < conf->set_size)
 136     {
 137       printf ("info: Test not run for CPU set size %zu\n", size);
 138       return true;
 139     }
 140
 141   cpu_set_t *initial_set = CPU_ALLOC (size);
 142   cpu_set_t *set2 = CPU_ALLOC (size);
 143   cpu_set_t *active_cpu_set = CPU_ALLOC (size);
 144
 145   if (initial_set == NULL || set2 == NULL || active_cpu_set == NULL)
 146     {
 147       printf ("error: size %zu: CPU_ALLOC failed\n", size);
 148       return false;
 149     }
 150   size_t kernel_size = CPU_ALLOC_SIZE (size);
 151
 152   if (getaffinity (kernel_size, initial_set) < 0)
 153     {
 154       printf ("error: size %zu: getaffinity: %m\n", size);
 155       return false;
 156     }
 157   if (setaffinity (kernel_size, initial_set) < 0)
 158     {
 159       printf ("error: size %zu: setaffinity: %m\n", size);
 160       return true;
 161     }
 162
 163   /* Use one-CPU set to test switching between CPUs.  */
 164   int last_active_cpu = -1;
 165   for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
 166     {
 167       int active_cpu = sched_getcpu ();
 168       if (last_active_cpu >= 0 && last_active_cpu != active_cpu)
 169         {
 170           printf ("error: Unexpected CPU %d, expected %d\n",
 171                   active_cpu, last_active_cpu);
 172           return false;
 173         }
 174
 175       if (!CPU_ISSET_S (cpu, kernel_size, initial_set))
 176         continue;
 177       last_active_cpu = cpu;
 178
 179       CPU_ZERO_S (kernel_size, active_cpu_set);
 180       CPU_SET_S (cpu, kernel_size, active_cpu_set);
 181       if (setaffinity (kernel_size, active_cpu_set) < 0)
 182         {
 183           printf ("error: size %zu: setaffinity (%d): %m\n", size, cpu);
 184           return false;
 185         }
 186       active_cpu = sched_getcpu ();
 187       if (active_cpu != cpu)
 188         {
 189           printf ("error: Unexpected CPU %d, expected %d\n", active_cpu, cpu);
 190           return false;
 191         }
 192       if (getaffinity (kernel_size, set2) < 0)
 193         {
 194           printf ("error: size %zu: getaffinity (2): %m\n", size);
 195           return false;
 196         }
 197       if (!CPU_EQUAL_S (kernel_size, active_cpu_set, set2))
 198         {
 199           printf ("error: size %zu: CPU sets do not match\n", size);
 200           return false;
 201         }
 202     }
 203
 204   /* Test setting the all-ones set.  */
 205   for (int cpu = 0; cpu < size; ++cpu)
 206     CPU_SET_S (cpu, kernel_size, set2);
 207   if (setaffinity (kernel_size, set2) < 0)
 208     {
 209       printf ("error: size %zu: setaffinity (3): %m\n", size);
 210       return false;
 211     }
 212
 213   if (setaffinity (kernel_size, initial_set) < 0)
 214     {
 215       printf ("error: size %zu: setaffinity (4): %m\n", size);
 216       return false;
 217     }
 218   if (getaffinity (kernel_size, set2) < 0)
 219     {
 220       printf ("error: size %zu: getaffinity (3): %m\n", size);
 221       return false;
 222     }
 223   if (!CPU_EQUAL_S (kernel_size, initial_set, set2))
 224     {
 225       printf ("error: size %zu: CPU sets do not match (2)\n", size);
 226       return false;
 227     }
 228
 229   CPU_FREE (initial_set);
 230   CPU_FREE (set2);
 231   CPU_FREE (active_cpu_set);
 232
 233   return true;
 234 }
 235
 236 static int
 237 do_test (void)
 238 {
 239   {
 240     cpu_set_t set;
 241     if (getaffinity (sizeof (set), &set) < 0 && errno == ENOSYS)
 242       {
 243         puts ("warning: getaffinity not supported, test cannot run");
 244         return 0;
 245       }
 246     if (sched_getcpu () < 0 && errno == ENOSYS)
 247       {
 248         puts ("warning: sched_getcpu not supported, test cannot run");
 249         return 0;
 250       }
 251   }
 252
 253   struct conf conf;
 254   setup_conf (&conf);
 255   printf ("info: Detected CPU set size (in bits): %d\n", conf.set_size);
 256   printf ("info: Maximum test CPU: %d\n", conf.last_cpu);
 257   if (conf.set_size < 0 || conf.last_cpu < 0)
 258     return 1;
 259
 260   if (!early_test (&conf))
 261     return 1;
 262
 263   bool error = false;
 264   error |= !test_size (&conf, 1024);
 265   error |= !test_size (&conf, conf.set_size);
 266   error |= !test_size (&conf, 2);
 267   error |= !test_size (&conf, 32);
 268   error |= !test_size (&conf, 40);
 269   error |= !test_size (&conf, 64);
 270   error |= !test_size (&conf, 96);
 271   error |= !test_size (&conf, 128);
 272   error |= !test_size (&conf, 256);
 273   error |= !test_size (&conf, 8192);
 274   return error;
 275 }
 276
 277 #define TEST_FUNCTION do_test ()
 278 #include "../test-skeleton.c"