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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); } |