1 /* Copyright (C) 2015-2020 Free Software Foundation, Inc.
2 Contributed by Sebastian Huber <sebastian.huber@embedded-brains.de>.
3
4 This file is part of the GNU Offloading and Multi Processing Library
5 (libgomp).
6
7 Libgomp is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 more details.
16
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
20
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
25
26 /* This file contains RTEMS specific routines related to counting
27 online processors and dynamic load balancing. */
28
29 #include "libgomp.h"
30 #include "pool.h"
31 #include <errno.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 struct gomp_thread_pool_reservoir **gomp_thread_pool_reservoirs;
37
38 __thread struct gomp_tls_rtems_data gomp_tls_rtems_data;
39
40 static void
allocate_thread_pool_reservoirs(void)41 allocate_thread_pool_reservoirs (void)
42 {
43 struct gomp_thread_pool_reservoir **reservoirs;
44 size_t size = _Sched_Count () * sizeof (*reservoirs);
45 reservoirs = gomp_malloc (size);
46 gomp_thread_pool_reservoirs = reservoirs;
47 memset (reservoirs, 0, size);
48 }
49
50 static void
allocate_thread_pool_reservoir(unsigned long count,unsigned long priority,unsigned long scheduler)51 allocate_thread_pool_reservoir (unsigned long count, unsigned long priority,
52 unsigned long scheduler)
53 {
54 struct gomp_thread_pool_reservoir *res;
55 struct gomp_thread_pool *pools;
56 unsigned long i;
57 size_t size;
58
59 res = gomp_thread_pool_reservoirs[scheduler];
60 if (res != NULL)
61 gomp_fatal ("Multiple thread pool reservoir initialization");
62 size = sizeof (*res) + count * (sizeof(pools) + sizeof(*pools));
63 pools = gomp_malloc (size);
64 memset (pools, 0, size);
65 res = (struct gomp_thread_pool_reservoir *) (pools + count);
66 res->index = count;
67 res->priority = priority;
68 gomp_sem_init (&res->available, count);
69 pthread_spin_init (&res->lock, PTHREAD_PROCESS_PRIVATE);
70 for (i = 0; i < count; ++i)
71 res->pools[i] = &pools[i];
72 gomp_thread_pool_reservoirs[scheduler] = res;
73 }
74
75 static char *
parse_thread_pools(char * env,unsigned long * count,unsigned long * priority,unsigned long * scheduler)76 parse_thread_pools (char *env, unsigned long *count, unsigned long *priority,
77 unsigned long *scheduler)
78 {
79 size_t len;
80 int i;
81
82 if (*env == ':')
83 ++env;
84
85 errno = 0;
86 *count = strtoul (env, &env, 10);
87 if (errno != 0)
88 gomp_fatal ("Invalid thread pool count");
89
90 if (*env == '$')
91 {
92 ++env;
93 errno = 0;
94 *priority = strtoul (env, &env, 10);
95 if (errno != 0)
96 gomp_fatal ("Invalid thread pool priority");
97 }
98 else
99 *priority = -1;
100
101 if (*env != '@')
102 gomp_fatal ("Invalid thread pool scheduler prefix");
103 ++env;
104
105 len = 0;
106 while (env[len] != '\0' && env[len] != ':')
107 ++len;
108 i = _Sched_Name_to_index (env, len);
109 if (i < 0)
110 gomp_fatal ("Invalid thread pool scheduler");
111 *scheduler = i;
112 env += len;
113
114 return env;
115 }
116
117 static void
init_thread_pool_reservoirs(void)118 init_thread_pool_reservoirs (void)
119 {
120 char *env = getenv ("GOMP_RTEMS_THREAD_POOLS");
121 if (env != NULL)
122 {
123 allocate_thread_pool_reservoirs ();
124 while (*env != '\0')
125 {
126 unsigned long count;
127 unsigned long priority;
128 unsigned long scheduler;
129 env = parse_thread_pools (env, &count, &priority, &scheduler);
130 allocate_thread_pool_reservoir (count, priority, scheduler);
131 }
132 }
133 }
134
135 void
gomp_init_num_threads(void)136 gomp_init_num_threads (void)
137 {
138 gomp_global_icv.nthreads_var = omp_get_num_procs();
139 init_thread_pool_reservoirs ();
140 }
141
142 unsigned
gomp_dynamic_max_threads(void)143 gomp_dynamic_max_threads (void)
144 {
145 unsigned n_onln = (unsigned) omp_get_num_procs();
146 unsigned nthreads_var = gomp_icv (false)->nthreads_var;
147
148 if (n_onln > nthreads_var)
149 return nthreads_var;
150 else
151 return n_onln;
152 }
153
154 int
omp_get_num_procs(void)155 omp_get_num_procs (void)
156 {
157 return sysconf (_SC_NPROCESSORS_ONLN);
158 }
159
160 ialias (omp_get_num_procs)
161