Mercurial > hg > CbC > CbC_gcc

comparison libgomp/config/posix/proc.c @ 0:a06113de4d67

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
first commit
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
parents
children 04ced10e8804
comparison
equal deleted inserted replaced
-1:000000000000 0:a06113de4d67
1 /* Copyright (C) 2005, 2006, 2008, 2009 Free Software Foundation, Inc.
2 Contributed by Richard Henderson <rth@redhat.com>.
3
4 This file is part of the GNU OpenMP Library (libgomp).
5
6 Libgomp is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10
11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 more details.
15
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
24
25 /* This file contains system specific routines related to counting
26 online processors and dynamic load balancing. It is expected that
27 a system may well want to write special versions of each of these.
28
29 The following implementation uses a mix of POSIX and BSD routines. */
30
31 #include "libgomp.h"
32 #include <unistd.h>
33 #include <stdlib.h>
34 #ifdef HAVE_GETLOADAVG
35 # ifdef HAVE_SYS_LOADAVG_H
36 # include <sys/loadavg.h>
37 # endif
38 #endif
39
40
41 /* At startup, determine the default number of threads. It would seem
42 this should be related to the number of cpus online. */
43
44 void
45 gomp_init_num_threads (void)
46 {
47 #ifdef _SC_NPROCESSORS_ONLN
48 gomp_global_icv.nthreads_var = sysconf (_SC_NPROCESSORS_ONLN);
49 #endif
50 }
51
52 /* When OMP_DYNAMIC is set, at thread launch determine the number of
53 threads we should spawn for this team. */
54 /* ??? I have no idea what best practice for this is. Surely some
55 function of the number of processors that are *still* online and
56 the load average. Here I use the number of processors online
57 minus the 15 minute load average. */
58
59 unsigned
60 gomp_dynamic_max_threads (void)
61 {
62 unsigned n_onln, loadavg;
63 unsigned nthreads_var = gomp_icv (false)->nthreads_var;
64
65 #ifdef _SC_NPROCESSORS_ONLN
66 n_onln = sysconf (_SC_NPROCESSORS_ONLN);
67 if (n_onln > nthreads_var)
68 n_onln = nthreads_var;
69 #else
70 n_onln = nthreads_var;
71 #endif
72
73 loadavg = 0;
74 #ifdef HAVE_GETLOADAVG
75 {
76 double dloadavg[3];
77 if (getloadavg (dloadavg, 3) == 3)
78 {
79 /* Add 0.1 to get a kind of biased rounding. */
80 loadavg = dloadavg[2] + 0.1;
81 }
82 }
83 #endif
84
85 if (loadavg >= n_onln)
86 return 1;
87 else
88 return n_onln - loadavg;
89 }
90
91 int
92 omp_get_num_procs (void)
93 {
94 #ifdef _SC_NPROCESSORS_ONLN
95 return sysconf (_SC_NPROCESSORS_ONLN);
96 #else
97 return gomp_icv (false)->nthreads_var;
98 #endif
99 }
100
101 ialias (omp_get_num_procs)