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/* Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
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
<http://www.gnu.org/licenses/>. */
#include <alloca.h>
#include <errno.h>
#include <pthreadP.h>
#include <sysdep.h>
#include <sys/types.h>
size_t __kernel_cpumask_size attribute_hidden;
/* Determine the current affinity. As a side affect we learn
about the size of the cpumask_t in the kernel. */
extern int __determine_cpumask_size (pid_t tid);
libpthread_hidden_proto(__determine_cpumask_size)
int __determine_cpumask_size (pid_t tid)
{
INTERNAL_SYSCALL_DECL (err);
int res;
size_t psize = 128;
void *p = alloca (psize);
while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, tid, psize, p),
INTERNAL_SYSCALL_ERROR_P (res, err)
&& INTERNAL_SYSCALL_ERRNO (res, err) == EINVAL)
p = extend_alloca (p, psize, 2 * psize);
if (res == 0 || INTERNAL_SYSCALL_ERROR_P (res, err))
return INTERNAL_SYSCALL_ERRNO (res, err);
__kernel_cpumask_size = res;
return 0;
}
libpthread_hidden_def(__determine_cpumask_size)
int
pthread_setaffinity_np (pthread_t th, size_t cpusetsize,
const cpu_set_t *cpuset)
{
const struct pthread *pd = (const struct pthread *) th;
INTERNAL_SYSCALL_DECL (err);
int res;
if (__builtin_expect (__kernel_cpumask_size == 0, 0))
{
res = __determine_cpumask_size (pd->tid);
if (res != 0)
return res;
}
/* We now know the size of the kernel cpumask_t. Make sure the user
does not request to set a bit beyond that. */
size_t cnt;
for (cnt = __kernel_cpumask_size; cnt < cpusetsize; ++cnt)
if (((char *) cpuset)[cnt] != '\0')
/* Found a nonzero byte. This means the user request cannot be
fulfilled. */
return EINVAL;
res = INTERNAL_SYSCALL (sched_setaffinity, err, 3, pd->tid, cpusetsize,
cpuset);
#ifdef RESET_VGETCPU_CACHE
if (!INTERNAL_SYSCALL_ERROR_P (res, err))
RESET_VGETCPU_CACHE ();
#endif
return (INTERNAL_SYSCALL_ERROR_P (res, err)
? INTERNAL_SYSCALL_ERRNO (res, err)
: 0);
}
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