glibc/sysdeps/unix/sysv/linux/sched_setaffinity.c
2014-02-10 15:07:12 +01:00

95 lines
2.7 KiB
C

/* Copyright (C) 2002-2014 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
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sched.h>
#include <string.h>
#include <sysdep.h>
#include <unistd.h>
#include <sys/types.h>
#include <shlib-compat.h>
#include <alloca.h>
#ifdef __NR_sched_setaffinity
static size_t __kernel_cpumask_size;
int
__sched_setaffinity_new (pid_t pid, size_t cpusetsize, const cpu_set_t *cpuset)
{
if (__glibc_unlikely (__kernel_cpumask_size == 0))
{
INTERNAL_SYSCALL_DECL (err);
int res;
size_t psize = 128;
void *p = alloca (psize);
while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, getpid (),
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))
{
__set_errno (INTERNAL_SYSCALL_ERRNO (res, err));
return -1;
}
__kernel_cpumask_size = res;
}
/* We now know the size of the kernel cpumask_t. Make sure the user
does not request to set a bit beyond that. */
for (size_t cnt = __kernel_cpumask_size; cnt < cpusetsize; ++cnt)
if (((char *) cpuset)[cnt] != '\0')
{
/* Found a nonzero byte. This means the user request cannot be
fulfilled. */
__set_errno (EINVAL);
return -1;
}
int result = INLINE_SYSCALL (sched_setaffinity, 3, pid, cpusetsize, cpuset);
#ifdef RESET_VGETCPU_CACHE
if (result != -1)
RESET_VGETCPU_CACHE ();
#endif
return result;
}
versioned_symbol (libc, __sched_setaffinity_new, sched_setaffinity,
GLIBC_2_3_4);
# if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
int
attribute_compat_text_section
__sched_setaffinity_old (pid_t pid, const cpu_set_t *cpuset)
{
/* The old interface by default assumed a 1024 processor bitmap. */
return __sched_setaffinity_new (pid, 128, cpuset);
}
compat_symbol (libc, __sched_setaffinity_old, sched_setaffinity, GLIBC_2_3_3);
# endif
#else
# include <posix/sched_setaffinity.c>
#endif