1 /* Copyright (C) 2015-2022 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 char *end;
82
83 if (*env == ':')
84 ++env;
85
86 errno = 0;
87 *count = strtoul (env, &end, 10);
88 if (errno != 0 || end == env)
89 gomp_fatal ("Invalid thread pool count");
90 env = end;
91
92 if (*env == '$')
93 {
94 ++env;
95 errno = 0;
96 *priority = strtoul (env, &end, 10);
97 if (errno != 0 || end == env)
98 gomp_fatal ("Invalid thread pool priority");
99 env = end;
100 }
101 else
102 *priority = -1;
103
104 if (*env != '@')
105 gomp_fatal ("Invalid thread pool scheduler prefix");
106 ++env;
107
108 len = 0;
109 while (env[len] != '\0' && env[len] != ':')
110 ++len;
111 i = _Sched_Name_to_index (env, len);
112 if (i < 0)
113 gomp_fatal ("Invalid thread pool scheduler");
114 *scheduler = i;
115 env += len;
116
117 return env;
118 }
119
120 static void
init_thread_pool_reservoirs(void)121 init_thread_pool_reservoirs (void)
122 {
123 char *env = getenv ("GOMP_RTEMS_THREAD_POOLS");
124 if (env != NULL)
125 {
126 allocate_thread_pool_reservoirs ();
127 while (*env != '\0')
128 {
129 unsigned long count;
130 unsigned long priority;
131 unsigned long scheduler;
132 env = parse_thread_pools (env, &count, &priority, &scheduler);
133 allocate_thread_pool_reservoir (count, priority, scheduler);
134 }
135 }
136 }
137
138 void
gomp_init_num_threads(void)139 gomp_init_num_threads (void)
140 {
141 gomp_global_icv.nthreads_var = omp_get_num_procs();
142 init_thread_pool_reservoirs ();
143 }
144
145 unsigned
gomp_dynamic_max_threads(void)146 gomp_dynamic_max_threads (void)
147 {
148 unsigned n_onln = (unsigned) omp_get_num_procs();
149 unsigned nthreads_var = gomp_icv (false)->nthreads_var;
150
151 if (n_onln > nthreads_var)
152 return nthreads_var;
153 else
154 return n_onln;
155 }
156
157 int
omp_get_num_procs(void)158 omp_get_num_procs (void)
159 {
160 return sysconf (_SC_NPROCESSORS_ONLN);
161 }
162
163 ialias (omp_get_num_procs)
164