Subversion Repositories HelenOS

Rev

Rev 827 | Rev 898 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1
/*
2
 * Copyright (C) 2001-2004 Jakub Jermar
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
29
#include <proc/scheduler.h>
30
#include <proc/thread.h>
31
#include <proc/task.h>
378 jermar 32
#include <mm/frame.h>
33
#include <mm/page.h>
703 jermar 34
#include <mm/as.h>
378 jermar 35
#include <arch/asm.h>
36
#include <arch/faddr.h>
37
#include <arch/atomic.h>
38
#include <synch/spinlock.h>
1 jermar 39
#include <config.h>
40
#include <context.h>
41
#include <func.h>
42
#include <arch.h>
788 jermar 43
#include <adt/list.h>
68 decky 44
#include <panic.h>
1 jermar 45
#include <typedefs.h>
378 jermar 46
#include <cpu.h>
195 vana 47
#include <print.h>
227 jermar 48
#include <debug.h>
1 jermar 49
 
475 jermar 50
atomic_t nrdy;
195 vana 51
 
897 jermar 52
/** Take actions before new thread runs.
107 decky 53
 *
118 jermar 54
 * Perform actions that need to be
55
 * taken before the newly selected
56
 * tread is passed control.
107 decky 57
 *
827 palkovsky 58
 * THREAD->lock is locked on entry
59
 *
107 decky 60
 */
52 vana 61
void before_thread_runs(void)
62
{
309 palkovsky 63
    before_thread_runs_arch();
458 decky 64
#ifdef CONFIG_FPU_LAZY
309 palkovsky 65
    if(THREAD==CPU->fpu_owner)
66
        fpu_enable();
67
    else
68
        fpu_disable();
69
#else
70
    fpu_enable();
71
    if (THREAD->fpu_context_exists)
72
        fpu_context_restore(&(THREAD->saved_fpu_context));
73
    else {
827 palkovsky 74
        fpu_init(&(THREAD->saved_fpu_context));
309 palkovsky 75
        THREAD->fpu_context_exists=1;
76
    }
77
#endif
52 vana 78
}
79
 
897 jermar 80
/** Take actions after old thread ran.
81
 *
82
 * Perform actions that need to be
83
 * taken after the running thread
84
 * was preempted by the scheduler.
85
 *
86
 * THREAD->lock is locked on entry
87
 *
88
 */
89
void after_thread_ran(void)
90
{
91
    after_thread_ran_arch();
92
}
93
 
458 decky 94
#ifdef CONFIG_FPU_LAZY
309 palkovsky 95
void scheduler_fpu_lazy_request(void)
96
{
97
    fpu_enable();
827 palkovsky 98
    spinlock_lock(&CPU->lock);
99
 
100
    /* Save old context */
309 palkovsky 101
    if (CPU->fpu_owner != NULL) {  
827 palkovsky 102
        spinlock_lock(&CPU->fpu_owner->lock);
309 palkovsky 103
        fpu_context_save(&CPU->fpu_owner->saved_fpu_context);
104
        /* don't prevent migration */
105
        CPU->fpu_owner->fpu_context_engaged=0;
827 palkovsky 106
        spinlock_unlock(&CPU->fpu_owner->lock);
309 palkovsky 107
    }
827 palkovsky 108
 
109
    spinlock_lock(&THREAD->lock);
309 palkovsky 110
    if (THREAD->fpu_context_exists)
111
        fpu_context_restore(&THREAD->saved_fpu_context);
112
    else {
827 palkovsky 113
        fpu_init(&(THREAD->saved_fpu_context));
309 palkovsky 114
        THREAD->fpu_context_exists=1;
115
    }
116
    CPU->fpu_owner=THREAD;
117
    THREAD->fpu_context_engaged = 1;
827 palkovsky 118
 
119
    spinlock_unlock(&THREAD->lock);
120
    spinlock_unlock(&CPU->lock);
309 palkovsky 121
}
122
#endif
52 vana 123
 
107 decky 124
/** Initialize scheduler
125
 *
126
 * Initialize kernel scheduler.
127
 *
128
 */
1 jermar 129
void scheduler_init(void)
130
{
131
}
132
 
107 decky 133
 
134
/** Get thread to be scheduled
135
 *
136
 * Get the optimal thread to be scheduled
109 jermar 137
 * according to thread accounting and scheduler
107 decky 138
 * policy.
139
 *
140
 * @return Thread to be scheduled.
141
 *
142
 */
483 jermar 143
static thread_t *find_best_thread(void)
1 jermar 144
{
145
    thread_t *t;
146
    runq_t *r;
783 palkovsky 147
    int i;
1 jermar 148
 
227 jermar 149
    ASSERT(CPU != NULL);
150
 
1 jermar 151
loop:
413 jermar 152
    interrupts_enable();
1 jermar 153
 
783 palkovsky 154
    if (atomic_get(&CPU->nrdy) == 0) {
1 jermar 155
        /*
156
         * For there was nothing to run, the CPU goes to sleep
157
         * until a hardware interrupt or an IPI comes.
158
         * This improves energy saving and hyperthreading.
159
         */
785 jermar 160
 
161
        /*
162
         * An interrupt might occur right now and wake up a thread.
163
         * In such case, the CPU will continue to go to sleep
164
         * even though there is a runnable thread.
165
         */
166
 
1 jermar 167
         cpu_sleep();
168
         goto loop;
169
    }
170
 
413 jermar 171
    interrupts_disable();
114 jermar 172
 
173
    i = 0;
174
    for (; i<RQ_COUNT; i++) {
15 jermar 175
        r = &CPU->rq[i];
1 jermar 176
        spinlock_lock(&r->lock);
177
        if (r->n == 0) {
178
            /*
179
             * If this queue is empty, try a lower-priority queue.
180
             */
181
            spinlock_unlock(&r->lock);
182
            continue;
183
        }
213 jermar 184
 
783 palkovsky 185
        atomic_dec(&CPU->nrdy);
475 jermar 186
        atomic_dec(&nrdy);
1 jermar 187
        r->n--;
188
 
189
        /*
190
         * Take the first thread from the queue.
191
         */
192
        t = list_get_instance(r->rq_head.next, thread_t, rq_link);
193
        list_remove(&t->rq_link);
194
 
195
        spinlock_unlock(&r->lock);
196
 
197
        spinlock_lock(&t->lock);
15 jermar 198
        t->cpu = CPU;
1 jermar 199
 
200
        t->ticks = us2ticks((i+1)*10000);
413 jermar 201
        t->priority = i;    /* eventually correct rq index */
1 jermar 202
 
203
        /*
204
         * Clear the X_STOLEN flag so that t can be migrated when load balancing needs emerge.
205
         */
206
        t->flags &= ~X_STOLEN;
207
        spinlock_unlock(&t->lock);
208
 
209
        return t;
210
    }
211
    goto loop;
212
 
213
}
214
 
107 decky 215
 
216
/** Prevent rq starvation
217
 *
218
 * Prevent low priority threads from starving in rq's.
219
 *
220
 * When the function decides to relink rq's, it reconnects
221
 * respective pointers so that in result threads with 'pri'
222
 * greater or equal 'start' are moved to a higher-priority queue.
223
 *
224
 * @param start Threshold priority.
225
 *
1 jermar 226
 */
452 decky 227
static void relink_rq(int start)
1 jermar 228
{
229
    link_t head;
230
    runq_t *r;
231
    int i, n;
232
 
233
    list_initialize(&head);
15 jermar 234
    spinlock_lock(&CPU->lock);
235
    if (CPU->needs_relink > NEEDS_RELINK_MAX) {
1 jermar 236
        for (i = start; i<RQ_COUNT-1; i++) {
237
            /* remember and empty rq[i + 1] */
15 jermar 238
            r = &CPU->rq[i + 1];
1 jermar 239
            spinlock_lock(&r->lock);
240
            list_concat(&head, &r->rq_head);
241
            n = r->n;
242
            r->n = 0;
243
            spinlock_unlock(&r->lock);
244
 
245
            /* append rq[i + 1] to rq[i] */
15 jermar 246
            r = &CPU->rq[i];
1 jermar 247
            spinlock_lock(&r->lock);
248
            list_concat(&r->rq_head, &head);
249
            r->n += n;
250
            spinlock_unlock(&r->lock);
251
        }
15 jermar 252
        CPU->needs_relink = 0;
1 jermar 253
    }
784 palkovsky 254
    spinlock_unlock(&CPU->lock);
1 jermar 255
 
256
}
257
 
107 decky 258
 
259
/** Scheduler stack switch wrapper
260
 *
261
 * Second part of the scheduler() function
262
 * using new stack. Handling the actual context
263
 * switch to a new thread.
264
 *
787 palkovsky 265
 * Assume THREAD->lock is held.
107 decky 266
 */
452 decky 267
static void scheduler_separated_stack(void)
1 jermar 268
{
269
    int priority;
270
 
227 jermar 271
    ASSERT(CPU != NULL);
272
 
15 jermar 273
    if (THREAD) {
897 jermar 274
        /* must be run after switch to scheduler stack */
275
        after_thread_ran();
276
 
15 jermar 277
        switch (THREAD->state) {
1 jermar 278
            case Running:
125 jermar 279
            THREAD->state = Ready;
280
            spinlock_unlock(&THREAD->lock);
281
            thread_ready(THREAD);
282
            break;
1 jermar 283
 
284
            case Exiting:
787 palkovsky 285
            thread_destroy(THREAD);
125 jermar 286
            break;
787 palkovsky 287
 
1 jermar 288
            case Sleeping:
125 jermar 289
            /*
290
             * Prefer the thread after it's woken up.
291
             */
413 jermar 292
            THREAD->priority = -1;
1 jermar 293
 
125 jermar 294
            /*
295
             * We need to release wq->lock which we locked in waitq_sleep().
296
             * Address of wq->lock is kept in THREAD->sleep_queue.
297
             */
298
            spinlock_unlock(&THREAD->sleep_queue->lock);
1 jermar 299
 
125 jermar 300
            /*
301
             * Check for possible requests for out-of-context invocation.
302
             */
303
            if (THREAD->call_me) {
304
                THREAD->call_me(THREAD->call_me_with);
305
                THREAD->call_me = NULL;
306
                THREAD->call_me_with = NULL;
307
            }
1 jermar 308
 
125 jermar 309
            spinlock_unlock(&THREAD->lock);
1 jermar 310
 
125 jermar 311
            break;
312
 
1 jermar 313
            default:
125 jermar 314
            /*
315
             * Entering state is unexpected.
316
             */
317
            panic("tid%d: unexpected state %s\n", THREAD->tid, thread_states[THREAD->state]);
318
            break;
1 jermar 319
        }
897 jermar 320
 
15 jermar 321
        THREAD = NULL;
1 jermar 322
    }
198 jermar 323
 
214 vana 324
 
15 jermar 325
    THREAD = find_best_thread();
1 jermar 326
 
15 jermar 327
    spinlock_lock(&THREAD->lock);
413 jermar 328
    priority = THREAD->priority;
15 jermar 329
    spinlock_unlock(&THREAD->lock);
192 jermar 330
 
1 jermar 331
    relink_rq(priority);       
332
 
15 jermar 333
    spinlock_lock(&THREAD->lock);  
1 jermar 334
 
335
    /*
336
     * If both the old and the new task are the same, lots of work is avoided.
337
     */
15 jermar 338
    if (TASK != THREAD->task) {
703 jermar 339
        as_t *as1 = NULL;
340
        as_t *as2;
1 jermar 341
 
15 jermar 342
        if (TASK) {
343
            spinlock_lock(&TASK->lock);
703 jermar 344
            as1 = TASK->as;
15 jermar 345
            spinlock_unlock(&TASK->lock);
1 jermar 346
        }
347
 
15 jermar 348
        spinlock_lock(&THREAD->task->lock);
703 jermar 349
        as2 = THREAD->task->as;
15 jermar 350
        spinlock_unlock(&THREAD->task->lock);
1 jermar 351
 
352
        /*
703 jermar 353
         * Note that it is possible for two tasks to share one address space.
1 jermar 354
         */
703 jermar 355
        if (as1 != as2) {
1 jermar 356
            /*
703 jermar 357
             * Both tasks and address spaces are different.
1 jermar 358
             * Replace the old one with the new one.
359
             */
823 jermar 360
            as_switch(as1, as2);
1 jermar 361
        }
15 jermar 362
        TASK = THREAD->task;   
1 jermar 363
    }
364
 
15 jermar 365
    THREAD->state = Running;
1 jermar 366
 
367
    #ifdef SCHEDULER_VERBOSE
823 jermar 368
    printf("cpu%d: tid %d (priority=%d,ticks=%d,nrdy=%d)\n", CPU->id, THREAD->tid, THREAD->priority, THREAD->ticks, atomic_get(&CPU->nrdy));
1 jermar 369
    #endif  
370
 
213 jermar 371
    /*
897 jermar 372
     * Some architectures provide late kernel PA2KA(identity)
373
     * mapping in a page fault handler. However, the page fault
374
     * handler uses the kernel stack of the running thread and
375
     * therefore cannot be used to map it. The kernel stack, if
376
     * necessary, is to be mapped in before_thread_runs(). This
377
     * function must be executed before the switch to the new stack.
378
     */
379
    before_thread_runs();
380
 
381
    /*
213 jermar 382
     * Copy the knowledge of CPU, TASK, THREAD and preemption counter to thread's stack.
383
     */
184 jermar 384
    the_copy(THE, (the_t *) THREAD->kstack);
385
 
15 jermar 386
    context_restore(&THREAD->saved_context);
1 jermar 387
    /* not reached */
388
}
389
 
107 decky 390
 
452 decky 391
/** The scheduler
392
 *
393
 * The thread scheduling procedure.
675 jermar 394
 * Passes control directly to
395
 * scheduler_separated_stack().
452 decky 396
 *
397
 */
398
void scheduler(void)
399
{
400
    volatile ipl_t ipl;
401
 
402
    ASSERT(CPU != NULL);
403
 
404
    ipl = interrupts_disable();
405
 
631 palkovsky 406
    if (atomic_get(&haltstate))
452 decky 407
        halt();
408
 
409
    if (THREAD) {
410
        spinlock_lock(&THREAD->lock);
458 decky 411
#ifndef CONFIG_FPU_LAZY
452 decky 412
        fpu_context_save(&(THREAD->saved_fpu_context));
413
#endif
414
        if (!context_save(&THREAD->saved_context)) {
415
            /*
416
             * This is the place where threads leave scheduler();
417
             */
418
            spinlock_unlock(&THREAD->lock);
419
            interrupts_restore(THREAD->saved_context.ipl);
420
            return;
421
        }
422
 
423
        /*
424
         * Interrupt priority level of preempted thread is recorded here
425
         * to facilitate scheduler() invocations from interrupts_disable()'d
426
         * code (e.g. waitq_sleep_timeout()).
427
         */
428
        THREAD->saved_context.ipl = ipl;
429
    }
430
 
431
    /*
557 jermar 432
     * Through the 'THE' structure, we keep track of THREAD, TASK, CPU, VM
452 decky 433
     * and preemption counter. At this point THE could be coming either
434
     * from THREAD's or CPU's stack.
435
     */
436
    the_copy(THE, (the_t *) CPU->stack);
437
 
438
    /*
439
     * We may not keep the old stack.
440
     * Reason: If we kept the old stack and got blocked, for instance, in
441
     * find_best_thread(), the old thread could get rescheduled by another
442
     * CPU and overwrite the part of its own stack that was also used by
443
     * the scheduler on this CPU.
444
     *
445
     * Moreover, we have to bypass the compiler-generated POP sequence
446
     * which is fooled by SP being set to the very top of the stack.
447
     * Therefore the scheduler() function continues in
448
     * scheduler_separated_stack().
449
     */
450
    context_save(&CPU->saved_context);
451
    context_set(&CPU->saved_context, FADDR(scheduler_separated_stack), (__address) CPU->stack, CPU_STACK_SIZE);
452
    context_restore(&CPU->saved_context);
453
    /* not reached */
454
}
455
 
456
 
457
 
458
 
459
 
458 decky 460
#ifdef CONFIG_SMP
107 decky 461
/** Load balancing thread
462
 *
463
 * SMP load balancing thread, supervising thread supplies
464
 * for the CPU it's wired to.
465
 *
466
 * @param arg Generic thread argument (unused).
467
 *
1 jermar 468
 */
469
void kcpulb(void *arg)
470
{
471
    thread_t *t;
783 palkovsky 472
    int count, average, i, j, k = 0;
413 jermar 473
    ipl_t ipl;
1 jermar 474
 
475
loop:
476
    /*
779 jermar 477
     * Work in 1s intervals.
1 jermar 478
     */
779 jermar 479
    thread_sleep(1);
1 jermar 480
 
481
not_satisfied:
482
    /*
483
     * Calculate the number of threads that will be migrated/stolen from
484
     * other CPU's. Note that situation can have changed between two
485
     * passes. Each time get the most up to date counts.
486
     */
784 palkovsky 487
    average = atomic_get(&nrdy) / config.cpu_active + 1;
783 palkovsky 488
    count = average - atomic_get(&CPU->nrdy);
1 jermar 489
 
784 palkovsky 490
    if (count <= 0)
1 jermar 491
        goto satisfied;
492
 
493
    /*
494
     * Searching least priority queues on all CPU's first and most priority queues on all CPU's last.
495
     */
496
    for (j=RQ_COUNT-1; j >= 0; j--) {
497
        for (i=0; i < config.cpu_active; i++) {
498
            link_t *l;
499
            runq_t *r;
500
            cpu_t *cpu;
501
 
502
            cpu = &cpus[(i + k) % config.cpu_active];
503
 
504
            /*
505
             * Not interested in ourselves.
506
             * Doesn't require interrupt disabling for kcpulb is X_WIRED.
507
             */
15 jermar 508
            if (CPU == cpu)
783 palkovsky 509
                continue;
510
            if (atomic_get(&cpu->nrdy) <= average)
511
                continue;
1 jermar 512
 
784 palkovsky 513
            ipl = interrupts_disable();
115 jermar 514
            r = &cpu->rq[j];
1 jermar 515
            spinlock_lock(&r->lock);
516
            if (r->n == 0) {
517
                spinlock_unlock(&r->lock);
413 jermar 518
                interrupts_restore(ipl);
1 jermar 519
                continue;
520
            }
521
 
522
            t = NULL;
523
            l = r->rq_head.prev;    /* search rq from the back */
524
            while (l != &r->rq_head) {
525
                t = list_get_instance(l, thread_t, rq_link);
526
                /*
125 jermar 527
                 * We don't want to steal CPU-wired threads neither threads already stolen.
1 jermar 528
                 * The latter prevents threads from migrating between CPU's without ever being run.
125 jermar 529
                 * We don't want to steal threads whose FPU context is still in CPU.
73 vana 530
                 */
1 jermar 531
                spinlock_lock(&t->lock);
73 vana 532
                if ( (!(t->flags & (X_WIRED | X_STOLEN))) && (!(t->fpu_context_engaged)) ) {
1 jermar 533
                    /*
534
                     * Remove t from r.
535
                     */
536
                    spinlock_unlock(&t->lock);
537
 
783 palkovsky 538
                    atomic_dec(&cpu->nrdy);
475 jermar 539
                    atomic_dec(&nrdy);
1 jermar 540
 
125 jermar 541
                    r->n--;
1 jermar 542
                    list_remove(&t->rq_link);
543
 
544
                    break;
545
                }
546
                spinlock_unlock(&t->lock);
547
                l = l->prev;
548
                t = NULL;
549
            }
550
            spinlock_unlock(&r->lock);
551
 
552
            if (t) {
553
                /*
554
                 * Ready t on local CPU
555
                 */
556
                spinlock_lock(&t->lock);
557
                #ifdef KCPULB_VERBOSE
783 palkovsky 558
                printf("kcpulb%d: TID %d -> cpu%d, nrdy=%d, avg=%d\n", CPU->id, t->tid, CPU->id, atomic_get(&CPU->nrdy), atomic_get(&nrdy) / config.cpu_active);
1 jermar 559
                #endif
560
                t->flags |= X_STOLEN;
561
                spinlock_unlock(&t->lock);
562
 
563
                thread_ready(t);
564
 
413 jermar 565
                interrupts_restore(ipl);
1 jermar 566
 
567
                if (--count == 0)
568
                    goto satisfied;
569
 
570
                /*
125 jermar 571
                 * We are not satisfied yet, focus on another CPU next time.
1 jermar 572
                 */
573
                k++;
574
 
575
                continue;
576
            }
413 jermar 577
            interrupts_restore(ipl);
1 jermar 578
        }
579
    }
580
 
783 palkovsky 581
    if (atomic_get(&CPU->nrdy)) {
1 jermar 582
        /*
583
         * Be a little bit light-weight and let migrated threads run.
584
         */
585
        scheduler();
779 jermar 586
    } else {
1 jermar 587
        /*
588
         * We failed to migrate a single thread.
779 jermar 589
         * Give up this turn.
1 jermar 590
         */
779 jermar 591
        goto loop;
1 jermar 592
    }
593
 
594
    goto not_satisfied;
125 jermar 595
 
1 jermar 596
satisfied:
597
    goto loop;
598
}
599
 
458 decky 600
#endif /* CONFIG_SMP */
775 palkovsky 601
 
602
 
603
/** Print information about threads & scheduler queues */
604
void sched_print_list(void)
605
{
606
    ipl_t ipl;
607
    int cpu,i;
608
    runq_t *r;
609
    thread_t *t;
610
    link_t *cur;
611
 
612
    /* We are going to mess with scheduler structures,
613
     * let's not be interrupted */
614
    ipl = interrupts_disable();
615
    printf("*********** Scheduler dump ***********\n");
616
    for (cpu=0;cpu < config.cpu_count; cpu++) {
617
        if (!cpus[cpu].active)
618
            continue;
619
        spinlock_lock(&cpus[cpu].lock);
620
        printf("cpu%d: nrdy: %d needs_relink: %d\n",
783 palkovsky 621
               cpus[cpu].id, atomic_get(&cpus[cpu].nrdy), cpus[cpu].needs_relink);
775 palkovsky 622
 
623
        for (i=0; i<RQ_COUNT; i++) {
624
            r = &cpus[cpu].rq[i];
625
            spinlock_lock(&r->lock);
626
            if (!r->n) {
627
                spinlock_unlock(&r->lock);
628
                continue;
629
            }
779 jermar 630
            printf("\tRq %d: ", i);
775 palkovsky 631
            for (cur=r->rq_head.next; cur!=&r->rq_head; cur=cur->next) {
632
                t = list_get_instance(cur, thread_t, rq_link);
633
                printf("%d(%s) ", t->tid,
634
                       thread_states[t->state]);
635
            }
636
            printf("\n");
637
            spinlock_unlock(&r->lock);
638
        }
639
        spinlock_unlock(&cpus[cpu].lock);
640
    }
641
 
642
    interrupts_restore(ipl);
643
}