diff options
Diffstat (limited to 'libc/nptl/sysdeps/unix/sysv/linux/pthread_setaffinity.c')
-rw-r--r-- | libc/nptl/sysdeps/unix/sysv/linux/pthread_setaffinity.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/libc/nptl/sysdeps/unix/sysv/linux/pthread_setaffinity.c b/libc/nptl/sysdeps/unix/sysv/linux/pthread_setaffinity.c new file mode 100644 index 000000000..3776e26e4 --- /dev/null +++ b/libc/nptl/sysdeps/unix/sysv/linux/pthread_setaffinity.c @@ -0,0 +1,99 @@ +/* Copyright (C) 2003, 2004, 2006 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <alloca.h> +#include <errno.h> +#include <pthreadP.h> +#include <sysdep.h> +#include <sys/types.h> +#include <shlib-compat.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. */ +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; +} + + +int +__pthread_setaffinity_new (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. */ + 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. */ + return EINVAL; + + res = INTERNAL_SYSCALL (sched_setaffinity, err, 3, pd->tid, cpusetsize, + cpuset); + return (INTERNAL_SYSCALL_ERROR_P (res, err) + ? INTERNAL_SYSCALL_ERRNO (res, err) + : 0); +} +versioned_symbol (libpthread, __pthread_setaffinity_new, + pthread_setaffinity_np, GLIBC_2_3_4); + + +#if SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_3_4) +int +__pthread_setaffinity_old (pthread_t th, cpu_set_t *cpuset) +{ + /* The old interface by default assumed a 1024 processor bitmap. */ + return __pthread_setaffinity_new (th, 128, cpuset); +} +compat_symbol (libpthread, __pthread_setaffinity_old, pthread_setaffinity_np, + GLIBC_2_3_3); +#endif |