scheduler.c 48.7 KB
Newer Older
1
2
/*******************************************************************************
 * This file is part of SWIFT.
3
 * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
4
 *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
5
 *               2016 Peter W. Draper (p.w.draper@durham.ac.uk)
6
 *
7
8
9
10
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
11
 *
12
13
14
15
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
16
 *
17
18
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
19
 *
20
21
22
23
24
25
 ******************************************************************************/

/* Config parameters. */
#include "../config.h"

/* Some standard headers. */
26
27
28
#include <limits.h>
#include <math.h>
#include <pthread.h>
29
30
31
32
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

33
34
/* MPI headers. */
#ifdef WITH_MPI
35
#include <mpi.h>
36
37
#endif

38
39
40
/* This object's header. */
#include "scheduler.h"

41
42
43
/* Local headers. */
#include "atomic.h"
#include "const.h"
44
#include "cycle.h"
45
#include "engine.h"
46
#include "error.h"
47
#include "intrinsics.h"
48
#include "kernel_hydro.h"
49
50
51
#include "queue.h"
#include "space.h"
#include "task.h"
52
#include "timers.h"
53

54
55
56
57
58
/**
 * @brief Re-set the list of active tasks.
 */
void scheduler_clear_active(struct scheduler *s) { s->active_count = 0; }

59
60
61
62
63
64
65
/**
 * @brief Add an unlock_task to the given task.
 *
 * @param s The #scheduler.
 * @param ta The unlocking #task.
 * @param tb The #task that will be unlocked.
 */
66
67
68
69
70
71
72
void scheduler_addunlock(struct scheduler *s, struct task *ta,
                         struct task *tb) {
  /* Get an index at which to store this unlock. */
  const int ind = atomic_inc(&s->nr_unlocks);

  /* Does the buffer need to be grown? */
  if (ind == s->size_unlocks) {
73
    /* Allocate the new buffer. */
74
75
76
    struct task **unlocks_new;
    int *unlock_ind_new;
    const int size_unlocks_new = s->size_unlocks * 2;
77
    if ((unlocks_new = (struct task **)malloc(sizeof(struct task *) *
78
                                              size_unlocks_new)) == NULL ||
79
80
        (unlock_ind_new = (int *)malloc(sizeof(int) * size_unlocks_new)) ==
            NULL)
81
      error("Failed to re-allocate unlocks.");
82

83
    /* Wait for all writes to the old buffer to complete. */
84
85
86
    while (s->completed_unlock_writes < ind)
      ;

87
    /* Copy the buffers. */
88
89
90
91
92
93
    memcpy(unlocks_new, s->unlocks, sizeof(struct task *) * ind);
    memcpy(unlock_ind_new, s->unlock_ind, sizeof(int) * ind);
    free(s->unlocks);
    free(s->unlock_ind);
    s->unlocks = unlocks_new;
    s->unlock_ind = unlock_ind_new;
94

95
    /* Publish the new buffer size. */
96
97
    s->size_unlocks = size_unlocks_new;
  }
98

99
  /* Wait for there to actually be space at my index. */
100
101
  while (ind > s->size_unlocks)
    ;
102
103
104
105

  /* Write the unlock to the scheduler. */
  s->unlocks[ind] = tb;
  s->unlock_ind[ind] = ta - s->tasks;
106
  atomic_inc(&s->completed_unlock_writes);
107
108
}

109
/**
110
 * @brief Split a task if too large.
111
 *
112
113
 * @param t The #task
 * @param s The #scheduler we are working in.
114
 */
115
static void scheduler_splittask(struct task *t, struct scheduler *s) {
116
117

  /* Static constants. */
118
  static const int pts[7][8] = {
Peter W. Draper's avatar
Peter W. Draper committed
119
120
121
122
      {-1, 12, 10, 9, 4, 3, 1, 0},     {-1, -1, 11, 10, 5, 4, 2, 1},
      {-1, -1, -1, 12, 7, 6, 4, 3},    {-1, -1, -1, -1, 8, 7, 5, 4},
      {-1, -1, -1, -1, -1, 12, 10, 9}, {-1, -1, -1, -1, -1, -1, 11, 10},
      {-1, -1, -1, -1, -1, -1, -1, 12}};
Matthieu Schaller's avatar
Matthieu Schaller committed
123
124
125
  static const float sid_scale[13] = {
      0.1897f, 0.4025f, 0.1897f, 0.4025f, 0.5788f, 0.4025f, 0.1897f,
      0.4025f, 0.1897f, 0.4025f, 0.5788f, 0.4025f, 0.5788f};
126

127
128
129
  /* Iterate on this task until we're done with it. */
  int redo = 1;
  while (redo) {
130

131
132
    /* Reset the redo flag. */
    redo = 0;
133

134
135
136
137
138
139
140
141
    /* Non-splittable task? */
    if ((t->ci == NULL || (t->type == task_type_pair && t->cj == NULL)) ||
        ((t->type == task_type_kick) && t->ci->nodeID != s->nodeID) ||
        ((t->type == task_type_init) && t->ci->nodeID != s->nodeID)) {
      t->type = task_type_none;
      t->skip = 1;
      break;
    }
142

143
144
    /* Self-interaction? */
    if (t->type == task_type_self) {
145

146
147
      /* Get a handle on the cell involved. */
      struct cell *ci = t->ci;
148
      const double hi = ci->dmin;
149
150
151

      /* Foreign task? */
      if (ci->nodeID != s->nodeID) {
152
        t->skip = 1;
153
        break;
154
155
      }

156
      /* Is this cell even split? */
157
      if (ci->split && ci->h_max * kernel_gamma * space_stretch < hi / 2) {
158

159
        /* Make a sub? */
160
        if (scheduler_dosub &&
161
162
            ((ci->count > 0 && ci->count < space_subsize / ci->count) ||
             (ci->gcount > 0 && ci->gcount < space_subsize / ci->gcount))) {
163

164
165
166
167
168
          /* convert to a self-subtask. */
          t->type = task_type_sub_self;

          /* Otherwise, make tasks explicitly. */
        } else {
169

170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
          /* Take a step back (we're going to recycle the current task)... */
          redo = 1;

          /* Add the self tasks. */
          int first_child = 0;
          while (ci->progeny[first_child] == NULL) first_child++;
          t->ci = ci->progeny[first_child];
          for (int k = first_child + 1; k < 8; k++)
            if (ci->progeny[k] != NULL)
              scheduler_splittask(
                  scheduler_addtask(s, task_type_self, t->subtype, 0, 0,
                                    ci->progeny[k], NULL, 0),
                  s);

          /* Make a task for each pair of progeny. */
          for (int j = 0; j < 8; j++)
            if (ci->progeny[j] != NULL)
              for (int k = j + 1; k < 8; k++)
                if (ci->progeny[k] != NULL)
                  scheduler_splittask(
                      scheduler_addtask(s, task_type_pair, t->subtype,
                                        pts[j][k], 0, ci->progeny[j],
                                        ci->progeny[k], 0),
                      s);
194
        }
195
      }
196

197
198
      /* Pair interaction? */
    } else if (t->type == task_type_pair && t->subtype != task_subtype_grav) {
199

200
201
202
203
204
      /* Get a handle on the cells involved. */
      struct cell *ci = t->ci;
      struct cell *cj = t->cj;
      const double hi = ci->dmin;
      const double hj = cj->dmin;
205

206
207
208
209
210
      /* Foreign task? */
      if (ci->nodeID != s->nodeID && cj->nodeID != s->nodeID) {
        t->skip = 1;
        break;
      }
211

212
213
214
215
      /* Get the sort ID, use space_getsid and not t->flags
         to make sure we get ci and cj swapped if needed. */
      double shift[3];
      int sid = space_getsid(s->space, &ci, &cj, shift);
216

217
218
219
220
221
222
223
      /* Should this task be split-up? */
      if (ci->split && cj->split &&
          ci->h_max * kernel_gamma * space_stretch < hi / 2 &&
          cj->h_max * kernel_gamma * space_stretch < hj / 2) {

        /* Replace by a single sub-task? */
        if (scheduler_dosub &&
224
            ci->count * sid_scale[sid] < space_subsize / cj->count &&
225
226
227
228
229
230
            sid != 0 && sid != 2 && sid != 6 && sid != 8) {

          /* Make this task a sub task. */
          t->type = task_type_sub_pair;

          /* Otherwise, split it. */
231
232
        } else {

233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
          /* Take a step back (we're going to recycle the current task)... */
          redo = 1;

          /* For each different sorting type... */
          switch (sid) {

            case 0: /* (  1 ,  1 ,  1 ) */
              t->ci = ci->progeny[7];
              t->cj = cj->progeny[0];
              t->flags = 0;
              break;

            case 1: /* (  1 ,  1 ,  0 ) */
              t->ci = ci->progeny[6];
              t->cj = cj->progeny[0];
              t->flags = 1;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 1, 0,
                                    ci->progeny[7], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[6], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              break;

            case 2: /* (  1 ,  1 , -1 ) */
              t->ci = ci->progeny[6];
              t->cj = cj->progeny[1];
              t->flags = 2;
              t->tight = 1;
              break;

            case 3: /* (  1 ,  0 ,  1 ) */
              t->ci = ci->progeny[5];
              t->cj = cj->progeny[0];
              t->flags = 3;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 3, 0,
                                    ci->progeny[7], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[5], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 6, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              break;

            case 4: /* (  1 ,  0 ,  0 ) */
              t->ci = ci->progeny[4];
              t->cj = cj->progeny[0];
              t->flags = 4;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 5, 0,
                                    ci->progeny[5], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[6], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 3, 0,
                                    ci->progeny[4], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 4, 0,
                                    ci->progeny[5], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 6, 0,
                                    ci->progeny[6], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[7], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 1, 0,
                                    ci->progeny[4], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[5], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 4, 0,
                                    ci->progeny[6], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 5, 0,
                                    ci->progeny[7], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[4], cj->progeny[3], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 1, 0,
                                    ci->progeny[5], cj->progeny[3], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 3, 0,
                                    ci->progeny[6], cj->progeny[3], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 4, 0,
                                    ci->progeny[7], cj->progeny[3], 1),
                  s);
              break;

            case 5: /* (  1 ,  0 , -1 ) */
              t->ci = ci->progeny[4];
              t->cj = cj->progeny[1];
              t->flags = 5;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 5, 0,
                                    ci->progeny[6], cj->progeny[3], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[4], cj->progeny[3], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[6], cj->progeny[1], 1),
                  s);
              break;

            case 6: /* (  1 , -1 ,  1 ) */
              t->ci = ci->progeny[5];
              t->cj = cj->progeny[2];
              t->flags = 6;
              t->tight = 1;
              break;

            case 7: /* (  1 , -1 ,  0 ) */
              t->ci = ci->progeny[4];
              t->cj = cj->progeny[3];
              t->flags = 6;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[5], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[4], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[5], cj->progeny[3], 1),
                  s);
              break;

            case 8: /* (  1 , -1 , -1 ) */
              t->ci = ci->progeny[4];
              t->cj = cj->progeny[3];
              t->flags = 8;
              t->tight = 1;
              break;

            case 9: /* (  0 ,  1 ,  1 ) */
              t->ci = ci->progeny[3];
              t->cj = cj->progeny[0];
              t->flags = 9;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 9, 0,
                                    ci->progeny[7], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[3], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              break;

            case 10: /* (  0 ,  1 ,  0 ) */
              t->ci = ci->progeny[2];
              t->cj = cj->progeny[0];
              t->flags = 10;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 11, 0,
                                    ci->progeny[3], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[6], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 6, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 9, 0,
                                    ci->progeny[2], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 10, 0,
                                    ci->progeny[3], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[6], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 7, 0,
                                    ci->progeny[7], cj->progeny[1], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 1, 0,
                                    ci->progeny[2], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[3], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 10, 0,
                                    ci->progeny[6], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 11, 0,
                                    ci->progeny[7], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[2], cj->progeny[5], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 1, 0,
                                    ci->progeny[3], cj->progeny[5], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 9, 0,
                                    ci->progeny[6], cj->progeny[5], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 10, 0,
                                    ci->progeny[7], cj->progeny[5], 1),
                  s);
              break;

            case 11: /* (  0 ,  1 , -1 ) */
              t->ci = ci->progeny[2];
              t->cj = cj->progeny[1];
              t->flags = 11;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 11, 0,
                                    ci->progeny[6], cj->progeny[5], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[2], cj->progeny[5], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 6, 0,
                                    ci->progeny[6], cj->progeny[1], 1),
                  s);
              break;

            case 12: /* (  0 ,  0 ,  1 ) */
              t->ci = ci->progeny[1];
              t->cj = cj->progeny[0];
              t->flags = 12;
              t->tight = 1;
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 11, 0,
                                    ci->progeny[3], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 5, 0,
                                    ci->progeny[5], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 2, 0,
                                    ci->progeny[7], cj->progeny[0], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 9, 0,
                                    ci->progeny[1], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 12, 0,
                                    ci->progeny[3], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 8, 0,
                                    ci->progeny[5], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 5, 0,
                                    ci->progeny[7], cj->progeny[2], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 3, 0,
                                    ci->progeny[1], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 6, 0,
                                    ci->progeny[3], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 12, 0,
                                    ci->progeny[5], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 11, 0,
                                    ci->progeny[7], cj->progeny[4], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                    ci->progeny[1], cj->progeny[6], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 3, 0,
                                    ci->progeny[3], cj->progeny[6], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 9, 0,
                                    ci->progeny[5], cj->progeny[6], 1),
                  s);
              scheduler_splittask(
                  scheduler_addtask(s, task_type_pair, t->subtype, 12, 0,
                                    ci->progeny[7], cj->progeny[6], 1),
                  s);
              break;
          } /* switch(sid) */
581
582
        }

583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
        /* Otherwise, break it up if it is too large? */
      } else if (scheduler_doforcesplit && ci->split && cj->split &&
                 (ci->count > space_maxsize / cj->count)) {

        // message( "force splitting pair with %i and %i parts." , ci->count ,
        // cj->count );

        /* Replace the current task. */
        t->type = task_type_none;

        for (int j = 0; j < 8; j++)
          if (ci->progeny[j] != NULL)
            for (int k = 0; k < 8; k++)
              if (cj->progeny[k] != NULL) {
                struct task *tl =
                    scheduler_addtask(s, task_type_pair, t->subtype, 0, 0,
                                      ci->progeny[j], cj->progeny[k], 0);
                scheduler_splittask(tl, s);
                tl->flags = space_getsid(s->space, &t->ci, &t->cj, shift);
              }

        /* Otherwise, if not spilt, stitch-up the sorting. */
      } else {

        /* Create the sort for ci. */
        lock_lock(&ci->lock);
        if (ci->sorts == NULL)
          ci->sorts = scheduler_addtask(s, task_type_sort, task_subtype_none,
                                        1 << sid, 0, ci, NULL, 0);
        else
          ci->sorts->flags |= (1 << sid);
        lock_unlock_blind(&ci->lock);
        scheduler_addunlock(s, ci->sorts, t);

        /* Create the sort for cj. */
        lock_lock(&cj->lock);
        if (cj->sorts == NULL)
          cj->sorts = scheduler_addtask(s, task_type_sort, task_subtype_none,
                                        1 << sid, 0, cj, NULL, 0);
        else
          cj->sorts->flags |= (1 << sid);
        lock_unlock_blind(&cj->lock);
        scheduler_addunlock(s, cj->sorts, t);
      }

    } /* pair interaction? */

    /* Long-range gravity interaction ? */
    else if (t->type == task_type_grav_mm) {

      /* Get a handle on the cells involved. */
      struct cell *ci = t->ci;

      /* Safety thing */
      if (ci->gcount == 0) t->type = task_type_none;

    } /* gravity interaction? */
  }   /* iterate over the current task. */
}

/**
 * @brief Mapper function to split tasks that may be too large.
 *
 * @param map_data the tasks to process
 * @param num_elements the number of tasks.
 * @param extra_data The #scheduler we are working in.
 */
void scheduler_splittasks_mapper(void *map_data, int num_elements,
                                 void *extra_data) {

  /* Extract the parameters. */
  struct scheduler *s = (struct scheduler *)extra_data;
  struct task *tasks = (struct task *)map_data;
656

657
658
659
  for (int ind = 0; ind < num_elements; ind++) {
    struct task *t = &tasks[ind];
    scheduler_splittask(t, s);
660
  }
661
}
662

Matthieu Schaller's avatar
Matthieu Schaller committed
663
664
665
666
667
/**
 * @brief Splits all the tasks in the scheduler that are too large.
 *
 * @param s The #scheduler.
 */
668
void scheduler_splittasks(struct scheduler *s) {
669

670
671
  /* Call the mapper on each current task. */
  threadpool_map(s->threadpool, scheduler_splittasks_mapper, s->tasks,
672
                 s->nr_tasks, sizeof(struct task), 1000, s);
673
674
}

675
676
677
678
679
680
681
/**
 * @brief Add a #task to the #scheduler.
 *
 * @param s The #scheduler we are working in.
 * @param type The type of the task.
 * @param subtype The sub-type of the task.
 * @param flags The flags of the task.
Matthieu Schaller's avatar
Matthieu Schaller committed
682
 * @param wait The number of unsatisfied dependencies of this task.
683
684
 * @param ci The first cell to interact.
 * @param cj The second cell to interact.
685
 * @param tight
686
 */
687
688
689
struct task *scheduler_addtask(struct scheduler *s, enum task_types type,
                               enum task_subtypes subtype, int flags, int wait,
                               struct cell *ci, struct cell *cj, int tight) {
690
691

  /* Get the next free task. */
Pedro Gonnet's avatar
Pedro Gonnet committed
692
  const int ind = atomic_inc(&s->tasks_next);
Matthieu Schaller's avatar
Matthieu Schaller committed
693

694
695
696
697
  /* Overflow? */
  if (ind >= s->size) error("Task list overflow.");

  /* Get a pointer to the new task. */
Pedro Gonnet's avatar
Pedro Gonnet committed
698
  struct task *t = &s->tasks[ind];
699
700
701
702
703
704
705
706

  /* Copy the data. */
  t->type = type;
  t->subtype = subtype;
  t->flags = flags;
  t->wait = wait;
  t->ci = ci;
  t->cj = cj;
707
  t->skip = 1; /* Mark tasks as skip by default. */
708
709
710
711
712
713
714
  t->tight = tight;
  t->implicit = 0;
  t->weight = 0;
  t->rank = 0;
  t->tic = 0;
  t->toc = 0;
  t->nr_unlock_tasks = 0;
715
  t->rid = -1;
716
717
718
719
720
721
722
723
724

  /* Add an index for it. */
  // lock_lock( &s->lock );
  s->tasks_ind[atomic_inc(&s->nr_tasks)] = ind;
  // lock_unlock_blind( &s->lock );

  /* Return a pointer to the new task. */
  return t;
}
725

726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
/**
 * @brief Set the unlock pointers in each task.
 *
 * @param s The #scheduler.
 */
void scheduler_set_unlocks(struct scheduler *s) {

  /* Store the counts for each task. */
  int *counts;
  if ((counts = (int *)malloc(sizeof(int) * s->nr_tasks)) == NULL)
    error("Failed to allocate temporary counts array.");
  bzero(counts, sizeof(int) * s->nr_tasks);
  for (int k = 0; k < s->nr_unlocks; k++) counts[s->unlock_ind[k]] += 1;

  /* Compute the offset for each unlock block. */
  int *offsets;
  if ((offsets = (int *)malloc(sizeof(int) * (s->nr_tasks + 1))) == NULL)
    error("Failed to allocate temporary offsets array.");
  offsets[0] = 0;
  for (int k = 0; k < s->nr_tasks; k++) offsets[k + 1] = offsets[k] + counts[k];

  /* Create and fill a temporary array with the sorted unlocks. */
  struct task **unlocks;
  if ((unlocks = (struct task **)malloc(sizeof(struct task *) *
                                        s->size_unlocks)) == NULL)
    error("Failed to allocate temporary unlocks array.");
  for (int k = 0; k < s->nr_unlocks; k++) {
    const int ind = s->unlock_ind[k];
    unlocks[offsets[ind]] = s->unlocks[k];
    offsets[ind] += 1;
  }

  /* Swap the unlocks. */
  free(s->unlocks);
  s->unlocks = unlocks;

  /* Re-set the offsets. */
  offsets[0] = 0;
  for (int k = 1; k < s->nr_tasks; k++)
    offsets[k] = offsets[k - 1] + counts[k - 1];

  /* Set the unlocks in the tasks. */
  for (int k = 0; k < s->nr_tasks; k++) {
    struct task *t = &s->tasks[k];
    t->nr_unlock_tasks = counts[k];
    t->unlock_tasks = &s->unlocks[offsets[k]];
  }
773

774
#ifdef SWIFT_DEBUG_CHECKS
775
  /* Verify that there are no duplicate unlocks. */
776
  for (int k = 0; k < s->nr_tasks; k++) {
777
778
779
780
781
782
783
    struct task *t = &s->tasks[k];
    for (int i = 0; i < t->nr_unlock_tasks; i++) {
      for (int j = i + 1; j < t->nr_unlock_tasks; j++) {
        if (t->unlock_tasks[i] == t->unlock_tasks[j])
          error("duplicate unlock!");
      }
    }
784
785
  }
#endif
786
787
788
789
790
791

  /* Clean up. */
  free(counts);
  free(offsets);
}

792
/**
793
794
795
796
 * @brief Sort the tasks in topological order over all queues.
 *
 * @param s The #scheduler.
 */
797
798
void scheduler_ranktasks(struct scheduler *s) {

Pedro Gonnet's avatar
Pedro Gonnet committed
799
800
801
  struct task *tasks = s->tasks;
  int *tid = s->tasks_ind;
  const int nr_tasks = s->nr_tasks;
802

803
  /* Run through the tasks and get all the waits right. */
804
805
806
807
808
809
810
811
  for (int i = 0; i < nr_tasks; i++) {
    struct task *t = &tasks[i];

    // Increment the waits of the dependances
    for (int k = 0; k < t->nr_unlock_tasks; k++) {
      t->unlock_tasks[k]->wait++;
    }
  }
812

813
814
815
816
817
818
819
820
  /* Load the tids of tasks with no waits. */
  int left = 0;
  for (int k = 0; k < nr_tasks; k++)
    if (tasks[k].wait == 0) {
      tid[left] = k;
      left += 1;
    }

821
  /* Main loop. */
822
  for (int j = 0, rank = 0; left < nr_tasks; rank++) {
823
824
825

    /* Did we get anything? */
    if (j == left) error("Unsatisfiable task dependencies detected.");
826
    const int left_old = left;
827
828

    /* Unlock the next layer of tasks. */
829
830
    for (; j < left_old; j++) {
      struct task *t = &tasks[tid[j]];
831
832
833
834
      t->rank = rank;
      /* message( "task %i of type %s has rank %i." , i ,
          (t->type == task_type_self) ? "self" : (t->type == task_type_pair) ?
         "pair" : "sort" , rank ); */
835
836
837
838
839
840
841
      for (int k = 0; k < t->nr_unlock_tasks; k++) {
        struct task *u = t->unlock_tasks[k];
        if (--u->wait == 0) {
          tid[left] = u - tasks;
          left += 1;
        }
      }
842
843
    }

844
845
    /* Move back to the old left (like Sanders). */
    j = left_old;
846
847
  }

848
#ifdef SWIFT_DEBUG_CHECKS
849
  /* Verify that the tasks were ranked correctly. */
850
  for (int k = 1; k < s->nr_tasks; k++)
851
    if (tasks[tid[k - 1]].rank > tasks[tid[k - 1]].rank)
852
853
      error("Task ranking failed.");
#endif
854
}
855
856
857
858
859
860
861

/**
 * @brief (Re)allocate the task arrays.
 *
 * @param s The #scheduler.
 * @param size The maximum number of tasks in the #scheduler.
 */
862
void scheduler_reset(struct scheduler *s, int size) {
863

864
865
  /* Do we need to re-allocate? */
  if (size > s->size) {
866

867
    /* Free existing task lists if necessary. */
868
869
    if (s->tasks != NULL) free(s->tasks);
    if (s->tasks_ind != NULL) free(s->tasks_ind);
870
    if (s->tid_active != NULL) free(s->tid_active);
871

872
    /* Allocate the new lists. */
873
874
875
876
877
    if (posix_memalign((void *)&s->tasks, task_align,
                       size * sizeof(struct task)) != 0)
      error("Failed to allocate task array.");

    if ((s->tasks_ind = (int *)malloc(sizeof(int) * size)) == NULL)
878
      error("Failed to allocate task lists.");
879
880
881

    if ((s->tid_active = (int *)malloc(sizeof(int) * size)) == NULL)
      error("Failed to allocate aactive task lists.");
882
  }
883

884
885
886
887
888
  /* Reset the counters. */
  s->size = size;
  s->nr_tasks = 0;
  s->tasks_next = 0;
  s->waiting = 0;
889
  s->nr_unlocks = 0;
890
  s->completed_unlock_writes = 0;
891
  s->active_count = 0;
892
893

  /* Set the task pointers in the queues. */
Pedro Gonnet's avatar
Pedro Gonnet committed
894
  for (int k = 0; k < s->nr_queues; k++) s->queues[k].tasks = s->tasks;
895
}
896
897

/**
898
 * @brief Compute the task weights
899
900
 *
 * @param s The #scheduler.
901
 * @param verbose Are we talkative?
902
 */
903
void scheduler_reweight(struct scheduler *s, int verbose) {
904

Pedro Gonnet's avatar
Pedro Gonnet committed
905
906
907
908
  const int nr_tasks = s->nr_tasks;
  int *tid = s->tasks_ind;
  struct task *tasks = s->tasks;
  const int nodeID = s->nodeID;
Pedro Gonnet's avatar
Pedro Gonnet committed
909
910
911
  const float sid_scale[13] = {0.1897, 0.4025, 0.1897, 0.4025, 0.5788,
                               0.4025, 0.1897, 0.4025, 0.1897, 0.4025,
                               0.5788, 0.4025, 0.5788};
Pedro Gonnet's avatar
Pedro Gonnet committed
912
  const float wscale = 0.001;
913
  const ticks tic = getticks();
914

915
  /* Run through the tasks backwards and set their weights. */
Pedro Gonnet's avatar
Pedro Gonnet committed
916
917
  for (int k = nr_tasks - 1; k >= 0; k--) {
    struct task *t = &tasks[tid[k]];
918
    t->weight = 0;
Pedro Gonnet's avatar
Pedro Gonnet committed
919
    for (int j = 0; j < t->nr_unlock_tasks; j++)
920
921
922
923
924
925
926
      if (t->unlock_tasks[j]->weight > t->weight)
        t->weight = t->unlock_tasks[j]->weight;
    if (!t->implicit && t->tic > 0)
      t->weight += wscale * (t->toc - t->tic);
    else
      switch (t->type) {
        case task_type_sort:
927
928
          t->weight += wscale * intrinsics_popcount(t->flags) * t->ci->count *
                       (sizeof(int) * 8 - intrinsics_clz(t->ci->count));
929
930
          break;
        case task_type_self:
931
          t->weight += 1 * wscale * t->ci->count * t->ci->count;
932
933
934
935
936
937
938
939
940
          break;
        case task_type_pair:
          if (t->ci->nodeID != nodeID || t->cj->nodeID != nodeID)
            t->weight +=
                3 * wscale * t->ci->count * t->cj->count * sid_scale[t->flags];
          else
            t->weight +=
                2 * wscale * t->ci->count * t->cj->count * sid_scale[t->flags];
          break;
941
        case task_type_sub_pair:
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
          if (t->ci->nodeID != nodeID || t->cj->nodeID != nodeID) {
            if (t->flags < 0)
              t->weight += 3 * wscale * t->ci->count * t->cj->count;
            else
              t->weight += 3 * wscale * t->ci->count * t->cj->count *
                           sid_scale[t->flags];
          } else {
            if (t->flags < 0)
              t->weight += 2 * wscale * t->ci->count * t->cj->count;
            else
              t->weight += 2 * wscale * t->ci->count * t->cj->count *
                           sid_scale[t->flags];
          }
          break;
        case task_type_sub_self:
          t->weight += 1 * wscale * t->ci->count * t->ci->count;
958
959
960
961
          break;
        case task_type_ghost:
          if (t->ci == t->ci->super) t->weight += wscale * t->ci->count;
          break;
Matthieu Schaller's avatar
Matthieu Schaller committed
962
963
964
965
        case task_type_kick:
          t->weight += wscale * t->ci->count;
          break;
        case task_type_init:
966
967
968
969
970
971
          t->weight += wscale * t->ci->count;
          break;
        default:
          break;
      }
  }
972
973
974
975

  if (verbose)
    message("took %.3f %s.", clocks_from_ticks(getticks() - tic),
            clocks_getunit());
976
977

  /* int min = tasks[0].weight, max = tasks[0].weight;
978
  for ( int k = 1 ; k < nr_tasks ; k++ )
979
980
981
982
983
984
      if ( tasks[k].weight < min )
          min = tasks[k].weight;
      else if ( tasks[k].weight > max )
          max = tasks[k].weight;
  message( "task weights are in [ %i , %i ]." , min , max ); */
}
985

Pedro Gonnet's avatar
Pedro Gonnet committed
986
987
988
989
/**
 * @brief #threadpool_map function which runs through the task
 *        graph and re-computes the task wait counters.
 */
990
991
void scheduler_rewait_mapper(void *map_data, int num_elements,
                             void *extra_data) {
Pedro Gonnet's avatar
Pedro Gonnet committed
992

993
  struct task *tasks = (struct task *)map_data;
Pedro Gonnet's avatar
Pedro Gonnet committed
994

995
996
  for (int ind = 0; ind < num_elements; ind++) {
    struct task *t = &tasks[ind];
Pedro Gonnet's avatar
Pedro Gonnet committed
997

998
    if (t->skip) continue;
Pedro Gonnet's avatar
Pedro Gonnet committed
999

1000
    /* Skip sort tasks that have already been performed */
For faster browsing, not all history is shown. View entire blame