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/* Generic test for CPU affinity functions, multi-threaded variant.
Copyright (C) 2015-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Before including this file, a test has to declare the helper
getaffinity and setaffinity functions described in
tst-skeleton-affinity.c, which is included below. */
#include <errno.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdlib.h>
#include <support/xthread.h>
#include <sys/time.h>
struct conf;
static bool early_test (struct conf *);
/* Arbitrary run time for each pass. */
#define PASS_TIMEOUT 2
/* There are two passes (one with sched_yield, one without), and we
double the timeout to be on the safe side. */
#define TIMEOUT (2 * PASS_TIMEOUT * 2)
#include "tst-skeleton-affinity.c"
/* 0 if still running, 1 of stopping requested. */
static int still_running;
/* 0 if no scheduling failures, 1 if failures are encountered. */
static int failed;
static void *
thread_burn_one_cpu (void *closure)
{
int cpu = (uintptr_t) closure;
while (__atomic_load_n (&still_running, __ATOMIC_RELAXED) == 0)
{
int current = sched_getcpu ();
if (sched_getcpu () != cpu)
{
printf ("error: Pinned thread %d ran on impossible cpu %d\n",
cpu, current);
__atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
/* Terminate early. */
__atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
}
}
return NULL;
}
struct burn_thread
{
pthread_t self;
struct conf *conf;
cpu_set_t *initial_set;
cpu_set_t *seen_set;
int thread;
};
static void *
thread_burn_any_cpu (void *closure)
{
struct burn_thread *param = closure;
/* Schedule this thread around a bit to see if it lands on another
CPU. Run this for 2 seconds, once with sched_yield, once
without. */
for (int pass = 1; pass <= 2; ++pass)
{
time_t start = time (NULL);
while (time (NULL) - start <= PASS_TIMEOUT)
{
int cpu = sched_getcpu ();
if (cpu > param->conf->last_cpu
|| !CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
param->initial_set))
{
printf ("error: Unpinned thread %d ran on impossible CPU %d\n",
param->thread, cpu);
__atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
return NULL;
}
CPU_SET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
param->seen_set);
if (pass == 1)
sched_yield ();
}
}
return NULL;
}
static void
stop_and_join_threads (struct conf *conf, cpu_set_t *set,
pthread_t *pinned_first, pthread_t *pinned_last,
struct burn_thread *other_first,
struct burn_thread *other_last)
{
__atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
for (pthread_t *p = pinned_first; p < pinned_last; ++p)
{
int cpu = p - pinned_first;
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
continue;
int ret = pthread_join (*p, NULL);
if (ret != 0)
{
printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
fflush (stdout);
/* Cannot shut down cleanly with threads still running. */
abort ();
}
}
for (struct burn_thread *p = other_first; p < other_last; ++p)
{
int cpu = p - other_first;
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
continue;
int ret = pthread_join (p->self, NULL);
if (ret != 0)
{
printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
fflush (stdout);
/* Cannot shut down cleanly with threads still running. */
abort ();
}
}
}
/* Tries to check that the initial set of CPUs is complete and that
the main thread will not run on any other threads. */
static bool
early_test (struct conf *conf)
{
pthread_t *pinned_threads
= calloc (conf->last_cpu + 1, sizeof (*pinned_threads));
struct burn_thread *other_threads
= calloc (conf->last_cpu + 1, sizeof (*other_threads));
cpu_set_t *initial_set = CPU_ALLOC (conf->set_size);
cpu_set_t *scratch_set = CPU_ALLOC (conf->set_size);
if (pinned_threads == NULL || other_threads == NULL
|| initial_set == NULL || scratch_set == NULL)
{
puts ("error: Memory allocation failure");
return false;
}
if (getaffinity (CPU_ALLOC_SIZE (conf->set_size), initial_set) < 0)
{
printf ("error: pthread_getaffinity_np failed: %m\n");
return false;
}
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
other_threads[cpu].conf = conf;
other_threads[cpu].initial_set = initial_set;
other_threads[cpu].thread = cpu;
other_threads[cpu].seen_set = CPU_ALLOC (conf->set_size);
if (other_threads[cpu].seen_set == NULL)
{
puts ("error: Memory allocation failure");
return false;
}
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size),
other_threads[cpu].seen_set);
}
pthread_attr_t attr;
int ret = pthread_attr_init (&attr);
if (ret != 0)
{
printf ("error: pthread_attr_init failed: %s\n", strerror (ret));
return false;
}
support_set_small_thread_stack_size (&attr);
/* Spawn a thread pinned to each available CPU. */
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
CPU_SET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
ret = pthread_attr_setaffinity_np
(&attr, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
if (ret != 0)
{
printf ("error: pthread_attr_setaffinity_np for CPU %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads, pinned_threads + cpu,
NULL, NULL);
return false;
}
ret = pthread_create (pinned_threads + cpu, &attr,
thread_burn_one_cpu, (void *) (uintptr_t) cpu);
if (ret != 0)
{
printf ("error: pthread_create for CPU %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads, pinned_threads + cpu,
NULL, NULL);
return false;
}
}
/* Spawn another set of threads running on all CPUs. */
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
ret = pthread_create (&other_threads[cpu].self,
support_small_stack_thread_attribute (),
thread_burn_any_cpu, other_threads + cpu);
if (ret != 0)
{
printf ("error: pthread_create for thread %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads,
pinned_threads + conf->last_cpu + 1,
other_threads, other_threads + cpu);
return false;
}
}
/* Main thread. */
struct burn_thread main_thread;
main_thread.conf = conf;
main_thread.initial_set = initial_set;
main_thread.seen_set = scratch_set;
main_thread.thread = -1;
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), main_thread.seen_set);
thread_burn_any_cpu (&main_thread);
stop_and_join_threads (conf, initial_set,
pinned_threads,
pinned_threads + conf->last_cpu + 1,
other_threads, other_threads + conf->last_cpu + 1);
printf ("info: Main thread ran on %d CPU(s) of %d available CPU(s)\n",
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set),
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), initial_set));
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
CPU_OR_S (CPU_ALLOC_SIZE (conf->set_size),
scratch_set, scratch_set, other_threads[cpu].seen_set);
CPU_FREE (other_threads[cpu].seen_set);
}
printf ("info: Other threads ran on %d CPU(s)\n",
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set));;
pthread_attr_destroy (&attr);
CPU_FREE (scratch_set);
CPU_FREE (initial_set);
free (pinned_threads);
free (other_threads);
return failed == 0;
}
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