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Rev | Author | Line No. | Line |
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1 | jermar | 1 | /* |
2 | * Copyright (C) 2001-2004 Jakub Jermar |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | #include <proc/scheduler.h> |
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30 | #include <proc/thread.h> |
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31 | #include <proc/task.h> |
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378 | jermar | 32 | #include <mm/heap.h> |
33 | #include <mm/frame.h> |
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34 | #include <mm/page.h> |
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703 | jermar | 35 | #include <mm/as.h> |
378 | jermar | 36 | #include <arch/asm.h> |
37 | #include <arch/faddr.h> |
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38 | #include <arch/atomic.h> |
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39 | #include <synch/spinlock.h> |
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1 | jermar | 40 | #include <config.h> |
41 | #include <context.h> |
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42 | #include <func.h> |
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43 | #include <arch.h> |
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44 | #include <list.h> |
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68 | decky | 45 | #include <panic.h> |
1 | jermar | 46 | #include <typedefs.h> |
378 | jermar | 47 | #include <cpu.h> |
195 | vana | 48 | #include <print.h> |
227 | jermar | 49 | #include <debug.h> |
1 | jermar | 50 | |
475 | jermar | 51 | atomic_t nrdy; |
195 | vana | 52 | |
118 | jermar | 53 | /** Take actions before new thread runs |
107 | decky | 54 | * |
118 | jermar | 55 | * Perform actions that need to be |
56 | * taken before the newly selected |
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57 | * tread is passed control. |
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107 | decky | 58 | * |
59 | */ |
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52 | vana | 60 | void before_thread_runs(void) |
61 | { |
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309 | palkovsky | 62 | before_thread_runs_arch(); |
458 | decky | 63 | #ifdef CONFIG_FPU_LAZY |
309 | palkovsky | 64 | if(THREAD==CPU->fpu_owner) |
65 | fpu_enable(); |
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66 | else |
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67 | fpu_disable(); |
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68 | #else |
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69 | fpu_enable(); |
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70 | if (THREAD->fpu_context_exists) |
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71 | fpu_context_restore(&(THREAD->saved_fpu_context)); |
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72 | else { |
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73 | fpu_init(); |
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74 | THREAD->fpu_context_exists=1; |
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75 | } |
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76 | #endif |
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52 | vana | 77 | } |
78 | |||
458 | decky | 79 | #ifdef CONFIG_FPU_LAZY |
309 | palkovsky | 80 | void scheduler_fpu_lazy_request(void) |
81 | { |
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82 | fpu_enable(); |
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83 | if (CPU->fpu_owner != NULL) { |
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84 | fpu_context_save(&CPU->fpu_owner->saved_fpu_context); |
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85 | /* don't prevent migration */ |
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86 | CPU->fpu_owner->fpu_context_engaged=0; |
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87 | } |
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88 | if (THREAD->fpu_context_exists) |
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89 | fpu_context_restore(&THREAD->saved_fpu_context); |
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90 | else { |
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91 | fpu_init(); |
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92 | THREAD->fpu_context_exists=1; |
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93 | } |
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94 | CPU->fpu_owner=THREAD; |
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95 | THREAD->fpu_context_engaged = 1; |
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96 | } |
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97 | #endif |
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52 | vana | 98 | |
107 | decky | 99 | /** Initialize scheduler |
100 | * |
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101 | * Initialize kernel scheduler. |
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102 | * |
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103 | */ |
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1 | jermar | 104 | void scheduler_init(void) |
105 | { |
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106 | } |
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107 | |||
107 | decky | 108 | |
109 | /** Get thread to be scheduled |
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110 | * |
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111 | * Get the optimal thread to be scheduled |
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109 | jermar | 112 | * according to thread accounting and scheduler |
107 | decky | 113 | * policy. |
114 | * |
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115 | * @return Thread to be scheduled. |
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116 | * |
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117 | */ |
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483 | jermar | 118 | static thread_t *find_best_thread(void) |
1 | jermar | 119 | { |
120 | thread_t *t; |
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121 | runq_t *r; |
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122 | int i, n; |
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123 | |||
227 | jermar | 124 | ASSERT(CPU != NULL); |
125 | |||
1 | jermar | 126 | loop: |
413 | jermar | 127 | interrupts_disable(); |
1 | jermar | 128 | |
15 | jermar | 129 | spinlock_lock(&CPU->lock); |
130 | n = CPU->nrdy; |
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131 | spinlock_unlock(&CPU->lock); |
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1 | jermar | 132 | |
413 | jermar | 133 | interrupts_enable(); |
1 | jermar | 134 | |
135 | if (n == 0) { |
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458 | decky | 136 | #ifdef CONFIG_SMP |
1 | jermar | 137 | /* |
138 | * If the load balancing thread is not running, wake it up and |
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139 | * set CPU-private flag that the kcpulb has been started. |
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140 | */ |
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15 | jermar | 141 | if (test_and_set(&CPU->kcpulbstarted) == 0) { |
125 | jermar | 142 | waitq_wakeup(&CPU->kcpulb_wq, 0); |
1 | jermar | 143 | goto loop; |
144 | } |
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458 | decky | 145 | #endif /* CONFIG_SMP */ |
1 | jermar | 146 | |
147 | /* |
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148 | * For there was nothing to run, the CPU goes to sleep |
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149 | * until a hardware interrupt or an IPI comes. |
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150 | * This improves energy saving and hyperthreading. |
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151 | * On the other hand, several hardware interrupts can be ignored. |
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152 | */ |
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153 | cpu_sleep(); |
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154 | goto loop; |
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155 | } |
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156 | |||
413 | jermar | 157 | interrupts_disable(); |
114 | jermar | 158 | |
159 | i = 0; |
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160 | retry: |
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161 | for (; i<RQ_COUNT; i++) { |
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15 | jermar | 162 | r = &CPU->rq[i]; |
1 | jermar | 163 | spinlock_lock(&r->lock); |
164 | if (r->n == 0) { |
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165 | /* |
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166 | * If this queue is empty, try a lower-priority queue. |
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167 | */ |
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168 | spinlock_unlock(&r->lock); |
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169 | continue; |
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170 | } |
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213 | jermar | 171 | |
115 | jermar | 172 | /* avoid deadlock with relink_rq() */ |
114 | jermar | 173 | if (!spinlock_trylock(&CPU->lock)) { |
174 | /* |
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175 | * Unlock r and try again. |
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176 | */ |
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177 | spinlock_unlock(&r->lock); |
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178 | goto retry; |
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179 | } |
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15 | jermar | 180 | CPU->nrdy--; |
181 | spinlock_unlock(&CPU->lock); |
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1 | jermar | 182 | |
475 | jermar | 183 | atomic_dec(&nrdy); |
1 | jermar | 184 | r->n--; |
185 | |||
186 | /* |
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187 | * Take the first thread from the queue. |
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188 | */ |
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189 | t = list_get_instance(r->rq_head.next, thread_t, rq_link); |
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190 | list_remove(&t->rq_link); |
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191 | |||
192 | spinlock_unlock(&r->lock); |
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193 | |||
194 | spinlock_lock(&t->lock); |
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15 | jermar | 195 | t->cpu = CPU; |
1 | jermar | 196 | |
197 | t->ticks = us2ticks((i+1)*10000); |
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413 | jermar | 198 | t->priority = i; /* eventually correct rq index */ |
1 | jermar | 199 | |
200 | /* |
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201 | * Clear the X_STOLEN flag so that t can be migrated when load balancing needs emerge. |
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202 | */ |
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203 | t->flags &= ~X_STOLEN; |
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204 | spinlock_unlock(&t->lock); |
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205 | |||
206 | return t; |
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207 | } |
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208 | goto loop; |
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209 | |||
210 | } |
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211 | |||
107 | decky | 212 | |
213 | /** Prevent rq starvation |
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214 | * |
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215 | * Prevent low priority threads from starving in rq's. |
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216 | * |
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217 | * When the function decides to relink rq's, it reconnects |
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218 | * respective pointers so that in result threads with 'pri' |
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219 | * greater or equal 'start' are moved to a higher-priority queue. |
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220 | * |
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221 | * @param start Threshold priority. |
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222 | * |
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1 | jermar | 223 | */ |
452 | decky | 224 | static void relink_rq(int start) |
1 | jermar | 225 | { |
226 | link_t head; |
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227 | runq_t *r; |
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228 | int i, n; |
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229 | |||
230 | list_initialize(&head); |
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15 | jermar | 231 | spinlock_lock(&CPU->lock); |
232 | if (CPU->needs_relink > NEEDS_RELINK_MAX) { |
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1 | jermar | 233 | for (i = start; i<RQ_COUNT-1; i++) { |
234 | /* remember and empty rq[i + 1] */ |
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15 | jermar | 235 | r = &CPU->rq[i + 1]; |
1 | jermar | 236 | spinlock_lock(&r->lock); |
237 | list_concat(&head, &r->rq_head); |
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238 | n = r->n; |
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239 | r->n = 0; |
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240 | spinlock_unlock(&r->lock); |
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241 | |||
242 | /* append rq[i + 1] to rq[i] */ |
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15 | jermar | 243 | r = &CPU->rq[i]; |
1 | jermar | 244 | spinlock_lock(&r->lock); |
245 | list_concat(&r->rq_head, &head); |
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246 | r->n += n; |
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247 | spinlock_unlock(&r->lock); |
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248 | } |
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15 | jermar | 249 | CPU->needs_relink = 0; |
1 | jermar | 250 | } |
15 | jermar | 251 | spinlock_unlock(&CPU->lock); |
1 | jermar | 252 | |
253 | } |
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254 | |||
107 | decky | 255 | |
256 | /** Scheduler stack switch wrapper |
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257 | * |
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258 | * Second part of the scheduler() function |
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259 | * using new stack. Handling the actual context |
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260 | * switch to a new thread. |
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261 | * |
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262 | */ |
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452 | decky | 263 | static void scheduler_separated_stack(void) |
1 | jermar | 264 | { |
265 | int priority; |
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266 | |||
227 | jermar | 267 | ASSERT(CPU != NULL); |
268 | |||
15 | jermar | 269 | if (THREAD) { |
270 | switch (THREAD->state) { |
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1 | jermar | 271 | case Running: |
125 | jermar | 272 | THREAD->state = Ready; |
273 | spinlock_unlock(&THREAD->lock); |
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274 | thread_ready(THREAD); |
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275 | break; |
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1 | jermar | 276 | |
277 | case Exiting: |
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125 | jermar | 278 | frame_free((__address) THREAD->kstack); |
279 | if (THREAD->ustack) { |
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280 | frame_free((__address) THREAD->ustack); |
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281 | } |
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1 | jermar | 282 | |
125 | jermar | 283 | /* |
284 | * Detach from the containing task. |
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285 | */ |
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286 | spinlock_lock(&TASK->lock); |
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287 | list_remove(&THREAD->th_link); |
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288 | spinlock_unlock(&TASK->lock); |
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73 | vana | 289 | |
125 | jermar | 290 | spinlock_unlock(&THREAD->lock); |
291 | |||
292 | spinlock_lock(&threads_lock); |
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293 | list_remove(&THREAD->threads_link); |
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294 | spinlock_unlock(&threads_lock); |
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73 | vana | 295 | |
125 | jermar | 296 | spinlock_lock(&CPU->lock); |
650 | jermar | 297 | if(CPU->fpu_owner==THREAD) |
298 | CPU->fpu_owner=NULL; |
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125 | jermar | 299 | spinlock_unlock(&CPU->lock); |
300 | |||
301 | free(THREAD); |
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302 | |||
303 | break; |
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304 | |||
1 | jermar | 305 | case Sleeping: |
125 | jermar | 306 | /* |
307 | * Prefer the thread after it's woken up. |
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308 | */ |
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413 | jermar | 309 | THREAD->priority = -1; |
1 | jermar | 310 | |
125 | jermar | 311 | /* |
312 | * We need to release wq->lock which we locked in waitq_sleep(). |
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313 | * Address of wq->lock is kept in THREAD->sleep_queue. |
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314 | */ |
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315 | spinlock_unlock(&THREAD->sleep_queue->lock); |
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1 | jermar | 316 | |
125 | jermar | 317 | /* |
318 | * Check for possible requests for out-of-context invocation. |
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319 | */ |
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320 | if (THREAD->call_me) { |
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321 | THREAD->call_me(THREAD->call_me_with); |
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322 | THREAD->call_me = NULL; |
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323 | THREAD->call_me_with = NULL; |
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324 | } |
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1 | jermar | 325 | |
125 | jermar | 326 | spinlock_unlock(&THREAD->lock); |
1 | jermar | 327 | |
125 | jermar | 328 | break; |
329 | |||
1 | jermar | 330 | default: |
125 | jermar | 331 | /* |
332 | * Entering state is unexpected. |
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333 | */ |
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334 | panic("tid%d: unexpected state %s\n", THREAD->tid, thread_states[THREAD->state]); |
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335 | break; |
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1 | jermar | 336 | } |
15 | jermar | 337 | THREAD = NULL; |
1 | jermar | 338 | } |
198 | jermar | 339 | |
214 | vana | 340 | |
15 | jermar | 341 | THREAD = find_best_thread(); |
1 | jermar | 342 | |
15 | jermar | 343 | spinlock_lock(&THREAD->lock); |
413 | jermar | 344 | priority = THREAD->priority; |
15 | jermar | 345 | spinlock_unlock(&THREAD->lock); |
192 | jermar | 346 | |
1 | jermar | 347 | relink_rq(priority); |
348 | |||
15 | jermar | 349 | spinlock_lock(&THREAD->lock); |
1 | jermar | 350 | |
351 | /* |
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352 | * If both the old and the new task are the same, lots of work is avoided. |
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353 | */ |
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15 | jermar | 354 | if (TASK != THREAD->task) { |
703 | jermar | 355 | as_t *as1 = NULL; |
356 | as_t *as2; |
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1 | jermar | 357 | |
15 | jermar | 358 | if (TASK) { |
359 | spinlock_lock(&TASK->lock); |
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703 | jermar | 360 | as1 = TASK->as; |
15 | jermar | 361 | spinlock_unlock(&TASK->lock); |
1 | jermar | 362 | } |
363 | |||
15 | jermar | 364 | spinlock_lock(&THREAD->task->lock); |
703 | jermar | 365 | as2 = THREAD->task->as; |
15 | jermar | 366 | spinlock_unlock(&THREAD->task->lock); |
1 | jermar | 367 | |
368 | /* |
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703 | jermar | 369 | * Note that it is possible for two tasks to share one address space. |
1 | jermar | 370 | */ |
703 | jermar | 371 | if (as1 != as2) { |
1 | jermar | 372 | /* |
703 | jermar | 373 | * Both tasks and address spaces are different. |
1 | jermar | 374 | * Replace the old one with the new one. |
375 | */ |
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703 | jermar | 376 | as_install(as2); |
1 | jermar | 377 | } |
15 | jermar | 378 | TASK = THREAD->task; |
1 | jermar | 379 | } |
380 | |||
15 | jermar | 381 | THREAD->state = Running; |
1 | jermar | 382 | |
383 | #ifdef SCHEDULER_VERBOSE |
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413 | jermar | 384 | printf("cpu%d: tid %d (priority=%d,ticks=%d,nrdy=%d)\n", CPU->id, THREAD->tid, THREAD->priority, THREAD->ticks, CPU->nrdy); |
1 | jermar | 385 | #endif |
386 | |||
213 | jermar | 387 | /* |
388 | * Copy the knowledge of CPU, TASK, THREAD and preemption counter to thread's stack. |
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389 | */ |
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184 | jermar | 390 | the_copy(THE, (the_t *) THREAD->kstack); |
391 | |||
15 | jermar | 392 | context_restore(&THREAD->saved_context); |
1 | jermar | 393 | /* not reached */ |
394 | } |
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395 | |||
107 | decky | 396 | |
452 | decky | 397 | /** The scheduler |
398 | * |
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399 | * The thread scheduling procedure. |
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675 | jermar | 400 | * Passes control directly to |
401 | * scheduler_separated_stack(). |
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452 | decky | 402 | * |
403 | */ |
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404 | void scheduler(void) |
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405 | { |
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406 | volatile ipl_t ipl; |
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407 | |||
408 | ASSERT(CPU != NULL); |
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409 | |||
410 | ipl = interrupts_disable(); |
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411 | |||
631 | palkovsky | 412 | if (atomic_get(&haltstate)) |
452 | decky | 413 | halt(); |
414 | |||
415 | if (THREAD) { |
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416 | spinlock_lock(&THREAD->lock); |
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458 | decky | 417 | #ifndef CONFIG_FPU_LAZY |
452 | decky | 418 | fpu_context_save(&(THREAD->saved_fpu_context)); |
419 | #endif |
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420 | if (!context_save(&THREAD->saved_context)) { |
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421 | /* |
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422 | * This is the place where threads leave scheduler(); |
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423 | */ |
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424 | before_thread_runs(); |
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425 | spinlock_unlock(&THREAD->lock); |
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426 | interrupts_restore(THREAD->saved_context.ipl); |
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427 | return; |
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428 | } |
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429 | |||
430 | /* |
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431 | * Interrupt priority level of preempted thread is recorded here |
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432 | * to facilitate scheduler() invocations from interrupts_disable()'d |
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433 | * code (e.g. waitq_sleep_timeout()). |
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434 | */ |
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435 | THREAD->saved_context.ipl = ipl; |
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436 | } |
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437 | |||
438 | /* |
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557 | jermar | 439 | * Through the 'THE' structure, we keep track of THREAD, TASK, CPU, VM |
452 | decky | 440 | * and preemption counter. At this point THE could be coming either |
441 | * from THREAD's or CPU's stack. |
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442 | */ |
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443 | the_copy(THE, (the_t *) CPU->stack); |
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444 | |||
445 | /* |
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446 | * We may not keep the old stack. |
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447 | * Reason: If we kept the old stack and got blocked, for instance, in |
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448 | * find_best_thread(), the old thread could get rescheduled by another |
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449 | * CPU and overwrite the part of its own stack that was also used by |
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450 | * the scheduler on this CPU. |
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451 | * |
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452 | * Moreover, we have to bypass the compiler-generated POP sequence |
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453 | * which is fooled by SP being set to the very top of the stack. |
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454 | * Therefore the scheduler() function continues in |
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455 | * scheduler_separated_stack(). |
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456 | */ |
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457 | context_save(&CPU->saved_context); |
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458 | context_set(&CPU->saved_context, FADDR(scheduler_separated_stack), (__address) CPU->stack, CPU_STACK_SIZE); |
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459 | context_restore(&CPU->saved_context); |
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460 | /* not reached */ |
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461 | } |
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462 | |||
463 | |||
464 | |||
465 | |||
466 | |||
458 | decky | 467 | #ifdef CONFIG_SMP |
107 | decky | 468 | /** Load balancing thread |
469 | * |
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470 | * SMP load balancing thread, supervising thread supplies |
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471 | * for the CPU it's wired to. |
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472 | * |
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473 | * @param arg Generic thread argument (unused). |
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474 | * |
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1 | jermar | 475 | */ |
476 | void kcpulb(void *arg) |
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477 | { |
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478 | thread_t *t; |
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479 | int count, i, j, k = 0; |
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413 | jermar | 480 | ipl_t ipl; |
1 | jermar | 481 | |
482 | loop: |
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483 | /* |
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484 | * Sleep until there's some work to do. |
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485 | */ |
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15 | jermar | 486 | waitq_sleep(&CPU->kcpulb_wq); |
1 | jermar | 487 | |
488 | not_satisfied: |
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489 | /* |
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490 | * Calculate the number of threads that will be migrated/stolen from |
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491 | * other CPU's. Note that situation can have changed between two |
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492 | * passes. Each time get the most up to date counts. |
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493 | */ |
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413 | jermar | 494 | ipl = interrupts_disable(); |
15 | jermar | 495 | spinlock_lock(&CPU->lock); |
625 | palkovsky | 496 | count = atomic_get(&nrdy) / config.cpu_active; |
15 | jermar | 497 | count -= CPU->nrdy; |
498 | spinlock_unlock(&CPU->lock); |
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413 | jermar | 499 | interrupts_restore(ipl); |
1 | jermar | 500 | |
501 | if (count <= 0) |
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502 | goto satisfied; |
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503 | |||
504 | /* |
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505 | * Searching least priority queues on all CPU's first and most priority queues on all CPU's last. |
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506 | */ |
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507 | for (j=RQ_COUNT-1; j >= 0; j--) { |
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508 | for (i=0; i < config.cpu_active; i++) { |
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509 | link_t *l; |
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510 | runq_t *r; |
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511 | cpu_t *cpu; |
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512 | |||
513 | cpu = &cpus[(i + k) % config.cpu_active]; |
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514 | |||
515 | /* |
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516 | * Not interested in ourselves. |
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517 | * Doesn't require interrupt disabling for kcpulb is X_WIRED. |
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518 | */ |
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15 | jermar | 519 | if (CPU == cpu) |
115 | jermar | 520 | continue; |
1 | jermar | 521 | |
413 | jermar | 522 | restart: ipl = interrupts_disable(); |
115 | jermar | 523 | r = &cpu->rq[j]; |
1 | jermar | 524 | spinlock_lock(&r->lock); |
525 | if (r->n == 0) { |
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526 | spinlock_unlock(&r->lock); |
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413 | jermar | 527 | interrupts_restore(ipl); |
1 | jermar | 528 | continue; |
529 | } |
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530 | |||
531 | t = NULL; |
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532 | l = r->rq_head.prev; /* search rq from the back */ |
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533 | while (l != &r->rq_head) { |
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534 | t = list_get_instance(l, thread_t, rq_link); |
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535 | /* |
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125 | jermar | 536 | * We don't want to steal CPU-wired threads neither threads already stolen. |
1 | jermar | 537 | * The latter prevents threads from migrating between CPU's without ever being run. |
125 | jermar | 538 | * We don't want to steal threads whose FPU context is still in CPU. |
73 | vana | 539 | */ |
1 | jermar | 540 | spinlock_lock(&t->lock); |
73 | vana | 541 | if ( (!(t->flags & (X_WIRED | X_STOLEN))) && (!(t->fpu_context_engaged)) ) { |
115 | jermar | 542 | |
1 | jermar | 543 | /* |
544 | * Remove t from r. |
||
545 | */ |
||
546 | |||
547 | spinlock_unlock(&t->lock); |
||
548 | |||
549 | /* |
||
550 | * Here we have to avoid deadlock with relink_rq(), |
||
551 | * because it locks cpu and r in a different order than we do. |
||
552 | */ |
||
553 | if (!spinlock_trylock(&cpu->lock)) { |
||
554 | /* Release all locks and try again. */ |
||
555 | spinlock_unlock(&r->lock); |
||
413 | jermar | 556 | interrupts_restore(ipl); |
1 | jermar | 557 | goto restart; |
558 | } |
||
559 | cpu->nrdy--; |
||
560 | spinlock_unlock(&cpu->lock); |
||
561 | |||
475 | jermar | 562 | atomic_dec(&nrdy); |
1 | jermar | 563 | |
125 | jermar | 564 | r->n--; |
1 | jermar | 565 | list_remove(&t->rq_link); |
566 | |||
567 | break; |
||
568 | } |
||
569 | spinlock_unlock(&t->lock); |
||
570 | l = l->prev; |
||
571 | t = NULL; |
||
572 | } |
||
573 | spinlock_unlock(&r->lock); |
||
574 | |||
575 | if (t) { |
||
576 | /* |
||
577 | * Ready t on local CPU |
||
578 | */ |
||
579 | spinlock_lock(&t->lock); |
||
580 | #ifdef KCPULB_VERBOSE |
||
15 | jermar | 581 | printf("kcpulb%d: TID %d -> cpu%d, nrdy=%d, avg=%d\n", CPU->id, t->tid, CPU->id, CPU->nrdy, nrdy / config.cpu_active); |
1 | jermar | 582 | #endif |
583 | t->flags |= X_STOLEN; |
||
584 | spinlock_unlock(&t->lock); |
||
585 | |||
586 | thread_ready(t); |
||
587 | |||
413 | jermar | 588 | interrupts_restore(ipl); |
1 | jermar | 589 | |
590 | if (--count == 0) |
||
591 | goto satisfied; |
||
592 | |||
593 | /* |
||
125 | jermar | 594 | * We are not satisfied yet, focus on another CPU next time. |
1 | jermar | 595 | */ |
596 | k++; |
||
597 | |||
598 | continue; |
||
599 | } |
||
413 | jermar | 600 | interrupts_restore(ipl); |
1 | jermar | 601 | } |
602 | } |
||
603 | |||
15 | jermar | 604 | if (CPU->nrdy) { |
1 | jermar | 605 | /* |
606 | * Be a little bit light-weight and let migrated threads run. |
||
607 | */ |
||
608 | scheduler(); |
||
609 | } |
||
610 | else { |
||
611 | /* |
||
612 | * We failed to migrate a single thread. |
||
613 | * Something more sophisticated should be done. |
||
614 | */ |
||
615 | scheduler(); |
||
616 | } |
||
617 | |||
618 | goto not_satisfied; |
||
125 | jermar | 619 | |
1 | jermar | 620 | satisfied: |
621 | /* |
||
622 | * Tell find_best_thread() to wake us up later again. |
||
623 | */ |
||
625 | palkovsky | 624 | atomic_set(&CPU->kcpulbstarted,0); |
1 | jermar | 625 | goto loop; |
626 | } |
||
627 | |||
458 | decky | 628 | #endif /* CONFIG_SMP */ |