Mercurial > hg > CbC > CbC_gcc
diff libgomp/config/posix/proc.c @ 0:a06113de4d67
first commit
author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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children | 04ced10e8804 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libgomp/config/posix/proc.c Fri Jul 17 14:47:48 2009 +0900 @@ -0,0 +1,101 @@ +/* Copyright (C) 2005, 2006, 2008, 2009 Free Software Foundation, Inc. + Contributed by Richard Henderson <rth@redhat.com>. + + This file is part of the GNU OpenMP Library (libgomp). + + Libgomp is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + Libgomp 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 General Public License for + more details. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + <http://www.gnu.org/licenses/>. */ + +/* This file contains system specific routines related to counting + online processors and dynamic load balancing. It is expected that + a system may well want to write special versions of each of these. + + The following implementation uses a mix of POSIX and BSD routines. */ + +#include "libgomp.h" +#include <unistd.h> +#include <stdlib.h> +#ifdef HAVE_GETLOADAVG +# ifdef HAVE_SYS_LOADAVG_H +# include <sys/loadavg.h> +# endif +#endif + + +/* At startup, determine the default number of threads. It would seem + this should be related to the number of cpus online. */ + +void +gomp_init_num_threads (void) +{ +#ifdef _SC_NPROCESSORS_ONLN + gomp_global_icv.nthreads_var = sysconf (_SC_NPROCESSORS_ONLN); +#endif +} + +/* When OMP_DYNAMIC is set, at thread launch determine the number of + threads we should spawn for this team. */ +/* ??? I have no idea what best practice for this is. Surely some + function of the number of processors that are *still* online and + the load average. Here I use the number of processors online + minus the 15 minute load average. */ + +unsigned +gomp_dynamic_max_threads (void) +{ + unsigned n_onln, loadavg; + unsigned nthreads_var = gomp_icv (false)->nthreads_var; + +#ifdef _SC_NPROCESSORS_ONLN + n_onln = sysconf (_SC_NPROCESSORS_ONLN); + if (n_onln > nthreads_var) + n_onln = nthreads_var; +#else + n_onln = nthreads_var; +#endif + + loadavg = 0; +#ifdef HAVE_GETLOADAVG + { + double dloadavg[3]; + if (getloadavg (dloadavg, 3) == 3) + { + /* Add 0.1 to get a kind of biased rounding. */ + loadavg = dloadavg[2] + 0.1; + } + } +#endif + + if (loadavg >= n_onln) + return 1; + else + return n_onln - loadavg; +} + +int +omp_get_num_procs (void) +{ +#ifdef _SC_NPROCESSORS_ONLN + return sysconf (_SC_NPROCESSORS_ONLN); +#else + return gomp_icv (false)->nthreads_var; +#endif +} + +ialias (omp_get_num_procs)