summaryrefslogtreecommitdiff
path: root/rts/Stats.c
blob: 0852ab58a048c22d4f2b7e4510bc82791656bbd1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
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
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
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
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
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
/* -----------------------------------------------------------------------------
 *
 * (c) The GHC Team, 1998-2005
 *
 * Statistics and timing-related functions.
 *
 * ---------------------------------------------------------------------------*/

#include "PosixSource.h"
#include "Rts.h"

#include "RtsFlags.h"
#include "RtsUtils.h"
#include "Schedule.h"
#include "Stats.h"
#include "Profiling.h"
#include "GetTime.h"
#include "sm/Storage.h"
#include "sm/GCThread.h"
#include "sm/BlockAlloc.h"

// for spin/yield counters
#include "sm/GC.h"
#include "ThreadPaused.h"
#include "Messages.h"

#include <string.h> // for memset

static Time
    start_init_cpu, start_init_elapsed,
    end_init_cpu,   end_init_elapsed,
    start_exit_cpu, start_exit_elapsed,
    start_exit_gc_elapsed, start_exit_gc_cpu,
    end_exit_cpu,   end_exit_elapsed,
    start_nonmoving_gc_cpu, start_nonmoving_gc_elapsed,
    start_nonmoving_gc_sync_elapsed;

#if defined(PROFILING)
static Time RP_start_time  = 0, RP_tot_time  = 0;  // retainer prof user time
static Time RPe_start_time = 0, RPe_tot_time = 0;  // retainer prof elap time

static Time HC_start_time, HC_tot_time = 0;     // heap census prof user time
static Time HCe_start_time, HCe_tot_time = 0;   // heap census prof elap time
#endif

#if defined(PROF_SPIN)
volatile StgWord64 whitehole_lockClosure_spin = 0;
volatile StgWord64 whitehole_lockClosure_yield = 0;
volatile StgWord64 whitehole_threadPaused_spin = 0;
volatile StgWord64 whitehole_executeMessage_spin = 0;
#endif

//
// All the stats!
//
// This is where we accumulate all the stats during execution, and it's also
// in a convenient form that we can copy over to a caller of getRTSStats().
//
static RTSStats stats;

static W_ GC_end_faults = 0;

static Time *GC_coll_cpu = NULL;
static Time *GC_coll_elapsed = NULL;
static Time *GC_coll_max_pause = NULL;

static void statsPrintf( char *s, ... ) GNUC3_ATTRIBUTE(format (PRINTF, 1, 2));
static void statsFlush( void );
static void statsClose( void );

/* -----------------------------------------------------------------------------
   Current elapsed time
   ------------------------------------------------------------------------- */

Time stat_getElapsedTime(void)
{
    return getProcessElapsedTime() - start_init_elapsed;
}

/* ---------------------------------------------------------------------------
   Measure the current MUT time, for profiling
   ------------------------------------------------------------------------ */

#if defined(PROFILING)
/*
  mut_user_time_during_RP() returns the MUT time during retainer profiling.
  The same is for mut_user_time_during_HC();
 */
static double
mut_user_time_during_RP( void )
{
    return TimeToSecondsDbl(RP_start_time - stats.gc_cpu_ns - RP_tot_time);
}

#endif /* PROFILING */

/* ---------------------------------------------------------------------------
   initStats0() has no dependencies, it can be called right at the beginning
   ------------------------------------------------------------------------ */

void
initStats0(void)
{
    start_init_cpu    = 0;
    start_init_elapsed = 0;
    end_init_cpu     = 0;
    end_init_elapsed  = 0;

    start_nonmoving_gc_cpu = 0;
    start_nonmoving_gc_elapsed = 0;
    start_nonmoving_gc_sync_elapsed = 0;

    start_exit_cpu    = 0;
    start_exit_elapsed = 0;
    start_exit_gc_cpu    = 0;
    start_exit_gc_elapsed = 0;
    end_exit_cpu     = 0;
    end_exit_elapsed  = 0;

#if defined(PROFILING)
    RP_start_time  = 0;
    RP_tot_time  = 0;
    RPe_start_time = 0;
    RPe_tot_time = 0;

    HC_start_time = 0;
    HC_tot_time = 0;
    HCe_start_time = 0;
    HCe_tot_time = 0;
#endif

    GC_end_faults = 0;

    stats = (RTSStats) {
        .gcs = 0,
        .major_gcs = 0,
        .allocated_bytes = 0,
        .max_live_bytes = 0,
        .max_large_objects_bytes = 0,
        .max_compact_bytes = 0,
        .max_slop_bytes = 0,
        .max_mem_in_use_bytes = 0,
        .cumulative_live_bytes = 0,
        .copied_bytes = 0,
        .par_copied_bytes = 0,
        .cumulative_par_max_copied_bytes = 0,
        .cumulative_par_balanced_copied_bytes = 0,
        .gc_spin_spin = 0,
        .gc_spin_yield = 0,
        .mut_spin_spin = 0,
        .mut_spin_yield = 0,
        .any_work = 0,
        .no_work = 0,
        .scav_find_work = 0,
        .init_cpu_ns = 0,
        .init_elapsed_ns = 0,
        .mutator_cpu_ns = 0,
        .mutator_elapsed_ns = 0,
        .gc_cpu_ns = 0,
        .gc_elapsed_ns = 0,
        .cpu_ns = 0,
        .elapsed_ns = 0,
        .nonmoving_gc_cpu_ns = 0,
        .nonmoving_gc_elapsed_ns = 0,
        .nonmoving_gc_max_elapsed_ns = 0,
        .nonmoving_gc_sync_elapsed_ns = 0,
        .nonmoving_gc_sync_max_elapsed_ns = 0,
        .gc = {
            .gen = 0,
            .threads = 0,
            .allocated_bytes = 0,
            .live_bytes = 0,
            .large_objects_bytes = 0,
            .compact_bytes = 0,
            .slop_bytes = 0,
            .mem_in_use_bytes = 0,
            .copied_bytes = 0,
            .par_max_copied_bytes = 0,
            .par_balanced_copied_bytes = 0,
            .sync_elapsed_ns = 0,
            .cpu_ns = 0,
            .elapsed_ns = 0,
            .nonmoving_gc_cpu_ns = 0,
            .nonmoving_gc_elapsed_ns = 0,
            .nonmoving_gc_sync_elapsed_ns = 0,
        }
    };
}

/* ---------------------------------------------------------------------------
   initStats1() can be called after setupRtsFlags()
   ------------------------------------------------------------------------ */

void initGenerationStats(void);

void
initStats1 (void)
{
    if (RtsFlags.GcFlags.giveStats >= VERBOSE_GC_STATS) {
        statsPrintf("    Alloc    Copied     Live     GC     GC      TOT      TOT  Page Flts\n");
        statsPrintf("    bytes     bytes     bytes   user   elap     user     elap\n");
    }
    GC_coll_cpu =
        (Time *)stgMallocBytes(
            sizeof(Time)*RtsFlags.GcFlags.generations,
            "initStats");
    GC_coll_elapsed =
        (Time *)stgMallocBytes(
            sizeof(Time)*RtsFlags.GcFlags.generations,
            "initStats");
    GC_coll_max_pause =
        (Time *)stgMallocBytes(
            sizeof(Time)*RtsFlags.GcFlags.generations,
            "initStats");
    initGenerationStats();
}

void
initGenerationStats()
{
    for (uint32_t i = 0; i < RtsFlags.GcFlags.generations; i++) {
        GC_coll_cpu[i] = 0;
        GC_coll_elapsed[i] = 0;
        GC_coll_max_pause[i] = 0;
    }
}

/* ---------------------------------------------------------------------------
   Reset stats of child process after fork()
   ------------------------------------------------------------------------ */

void resetChildProcessStats()
{
    initStats0();
    initGenerationStats();
}

/* -----------------------------------------------------------------------------
   Initialisation time...
   -------------------------------------------------------------------------- */

void
stat_startInit(void)
{
    getProcessTimes(&start_init_cpu, &start_init_elapsed);
}

void
stat_endInit(void)
{
    getProcessTimes(&end_init_cpu, &end_init_elapsed);
    stats.init_cpu_ns = end_init_cpu - start_init_cpu;
    stats.init_elapsed_ns = end_init_elapsed - start_init_elapsed;
}

/* -----------------------------------------------------------------------------
   stat_startExit and stat_endExit

   These two measure the time taken in shutdownHaskell().
   -------------------------------------------------------------------------- */

void
stat_startExit(void)
{
    getProcessTimes(&start_exit_cpu, &start_exit_elapsed);
    start_exit_gc_elapsed = stats.gc_elapsed_ns;
    start_exit_gc_cpu = stats.gc_cpu_ns;
}

/* -----------------------------------------------------------------------------
   Nonmoving (concurrent) collector statistics

   These two measure the time taken in the concurrent mark & sweep collector.
   -------------------------------------------------------------------------- */
void
stat_endExit(void)
{
    getProcessTimes(&end_exit_cpu, &end_exit_elapsed);
}

void
stat_startGCSync (gc_thread *gct)
{
    gct->gc_sync_start_elapsed = getProcessElapsedTime();
}

void
stat_startNonmovingGc ()
{
    start_nonmoving_gc_cpu = getCurrentThreadCPUTime();
    start_nonmoving_gc_elapsed = getProcessCPUTime();
}

void
stat_endNonmovingGc ()
{
    Time cpu = getCurrentThreadCPUTime();
    Time elapsed = getProcessCPUTime();
    stats.gc.nonmoving_gc_elapsed_ns = elapsed - start_nonmoving_gc_elapsed;
    stats.nonmoving_gc_elapsed_ns += stats.gc.nonmoving_gc_elapsed_ns;

    stats.gc.nonmoving_gc_cpu_ns = cpu - start_nonmoving_gc_cpu;
    stats.nonmoving_gc_cpu_ns += stats.gc.nonmoving_gc_cpu_ns;

    stats.nonmoving_gc_max_elapsed_ns =
      stg_max(stats.gc.nonmoving_gc_elapsed_ns,
              stats.nonmoving_gc_max_elapsed_ns);
}

void
stat_startNonmovingGcSync ()
{
    start_nonmoving_gc_sync_elapsed = getProcessElapsedTime();
    traceConcSyncBegin();
}

void
stat_endNonmovingGcSync ()
{
    Time end_elapsed = getProcessElapsedTime();
    stats.gc.nonmoving_gc_sync_elapsed_ns = end_elapsed - start_nonmoving_gc_sync_elapsed;
    stats.nonmoving_gc_sync_elapsed_ns +=  stats.gc.nonmoving_gc_sync_elapsed_ns;
    stats.nonmoving_gc_sync_max_elapsed_ns =
      stg_max(stats.gc.nonmoving_gc_sync_elapsed_ns,
              stats.nonmoving_gc_sync_max_elapsed_ns);
    if (RtsFlags.GcFlags.giveStats == VERBOSE_GC_STATS) {
      statsPrintf("# sync %6.3f\n", TimeToSecondsDbl(stats.gc.nonmoving_gc_sync_elapsed_ns));
    }
    traceConcSyncEnd();
}

/* -----------------------------------------------------------------------------
   Called at the beginning of each GC
   -------------------------------------------------------------------------- */

/*
 * Note [Time accounting]
 * ~~~~~~~~~~~~~~~~~~~~~~
 * In the "vanilla" configuration (using the standard copying GC) GHC keeps
 * track of a two different sinks of elapsed and CPU time:
 *
 *  - time spent synchronising to initiate garbage collection
 *  - garbage collection (per generation)
 *  - mutation
 *
 * When using the (concurrent) non-moving garbage collector (see Note
 * [Non-moving garbage collector]) we also track a few more sinks:
 *
 *  - minor GC
 *  - major GC (namly time spent in the preparatory phase)
 *  - concurrent mark
 *  - final synchronization (elapsed only)
 *  - mutation
 *
 * To keep track of these CPU times we rely on the system's per-thread CPU time
 * clock (exposed via the runtime's getCurrentThreadCPUTime utility).
 *
 * CPU time spent in the copying garbage collector is tracked in each GC
 * worker's gc_thread struct. At the beginning of scavenging each worker
 * records its OS thread's CPU time its gc_thread (by stat_startGCWorker). At
 * the end of scavenging we again record the CPU time (in stat_endGCworker).
 * The differences of these are then summed over by the thread leading the GC
 * at the end of collection in stat_endGC. By contrast, the elapsed time is
 * recorded only by the leader.
 *
 * Mutator time is derived from the process's CPU time, subtracting out
 * contributions from stop-the-world and concurrent GCs.
 *
 * Time spent in concurrent marking is recorded by stat_{start,end}NonmovingGc.
 * Likewise, elapsed time spent in the final synchronization is recorded by
 * stat_{start,end}NonmovingGcSync.
 */

void
stat_startGCWorker (Capability *cap STG_UNUSED, gc_thread *gct)
{
    bool stats_enabled =
        RtsFlags.GcFlags.giveStats != NO_GC_STATS ||
        rtsConfig.gcDoneHook != NULL;

    if (stats_enabled || RtsFlags.ProfFlags.doHeapProfile) {
        gct->gc_start_cpu = getCurrentThreadCPUTime();
    }
}

void
stat_endGCWorker (Capability *cap STG_UNUSED, gc_thread *gct)
{
    bool stats_enabled =
        RtsFlags.GcFlags.giveStats != NO_GC_STATS ||
        rtsConfig.gcDoneHook != NULL;

    if (stats_enabled || RtsFlags.ProfFlags.doHeapProfile) {
        gct->gc_end_cpu = getCurrentThreadCPUTime();
        ASSERT(gct->gc_end_cpu >= gct->gc_start_cpu);
    }
}

void
stat_startGC (Capability *cap, gc_thread *gct)
{
    if (RtsFlags.GcFlags.ringBell) {
        debugBelch("\007");
    }

    bool stats_enabled =
        RtsFlags.GcFlags.giveStats != NO_GC_STATS ||
        rtsConfig.gcDoneHook != NULL;

    if (stats_enabled || RtsFlags.ProfFlags.doHeapProfile) {
        gct->gc_start_cpu = getCurrentThreadCPUTime();
    }

    gct->gc_start_elapsed = getProcessElapsedTime();

    // Post EVENT_GC_START with the same timestamp as used for stats
    // (though converted from Time=StgInt64 to EventTimestamp=StgWord64).
    // Here, as opposed to other places, the event is emitted on the cap
    // that initiates the GC and external tools expect it to have the same
    // timestamp as used in +RTS -s calculcations.
    traceEventGcStartAtT(cap,
                         TimeToNS(gct->gc_start_elapsed - start_init_elapsed));

    if (RtsFlags.GcFlags.giveStats != NO_GC_STATS)
    {
        gct->gc_start_faults = getPageFaults();
    }

    updateNurseriesStats();
}

/* -----------------------------------------------------------------------------
   Called at the end of each GC
   -------------------------------------------------------------------------- */

void
stat_endGC (Capability *cap, gc_thread *initiating_gct, W_ live, W_ copied, W_ slop,
            uint32_t gen, uint32_t par_n_threads, gc_thread **gc_threads,
            W_ par_max_copied, W_ par_balanced_copied, W_ gc_spin_spin, W_ gc_spin_yield,
            W_ mut_spin_spin, W_ mut_spin_yield, W_ any_work, W_ no_work,
            W_ scav_find_work)
{
    // -------------------------------------------------
    // Collect all the stats about this GC in stats.gc. We always do this since
    // it's relatively cheap and we need allocated_bytes to catch heap
    // overflows.

    stats.gc.gen = gen;
    stats.gc.threads = par_n_threads;

    uint64_t tot_alloc_bytes = calcTotalAllocated() * sizeof(W_);

    // allocated since the last GC
    stats.gc.allocated_bytes = tot_alloc_bytes - stats.allocated_bytes;

    stats.gc.live_bytes = live * sizeof(W_);
    stats.gc.large_objects_bytes = calcTotalLargeObjectsW() * sizeof(W_);
    stats.gc.compact_bytes = calcTotalCompactW() * sizeof(W_);
    stats.gc.slop_bytes = slop * sizeof(W_);
    stats.gc.mem_in_use_bytes = mblocks_allocated * MBLOCK_SIZE;
    stats.gc.copied_bytes = copied * sizeof(W_);
    stats.gc.par_max_copied_bytes = par_max_copied * sizeof(W_);
    stats.gc.par_balanced_copied_bytes = par_balanced_copied * sizeof(W_);

    bool stats_enabled =
        RtsFlags.GcFlags.giveStats != NO_GC_STATS ||
        rtsConfig.gcDoneHook != NULL;

    if (stats_enabled
      || RtsFlags.ProfFlags.doHeapProfile) // heap profiling needs GC_tot_time
    {
        // We only update the times when stats are explicitly enabled since
        // getProcessTimes (e.g. requiring a system call) can be expensive on
        // some platforms.
        Time current_cpu, current_elapsed;
        getProcessTimes(&current_cpu, &current_elapsed);
        stats.cpu_ns = current_cpu - start_init_cpu;
        stats.elapsed_ns = current_elapsed - start_init_elapsed;

        stats.gc.sync_elapsed_ns =
            initiating_gct->gc_start_elapsed - initiating_gct->gc_sync_start_elapsed;
        stats.gc.elapsed_ns = current_elapsed - initiating_gct->gc_start_elapsed;
        stats.gc.cpu_ns = 0;
        for (unsigned int i=0; i < par_n_threads; i++) {
            gc_thread *gct = gc_threads[i];
            ASSERT(gct->gc_end_cpu >= gct->gc_start_cpu);
            stats.gc.cpu_ns += gct->gc_end_cpu - gct->gc_start_cpu;
        }
    }
    // -------------------------------------------------
    // Update the cumulative stats

    stats.gcs++;
    stats.allocated_bytes = tot_alloc_bytes;
    stats.max_mem_in_use_bytes = peak_mblocks_allocated * MBLOCK_SIZE;

    GC_coll_cpu[gen] += stats.gc.cpu_ns;
    GC_coll_elapsed[gen] += stats.gc.elapsed_ns;
    if (GC_coll_max_pause[gen] < stats.gc.elapsed_ns) {
        GC_coll_max_pause[gen] = stats.gc.elapsed_ns;
    }

    stats.copied_bytes += stats.gc.copied_bytes;
    if (par_n_threads > 1) {
        stats.par_copied_bytes += stats.gc.copied_bytes;
        stats.cumulative_par_max_copied_bytes +=
            stats.gc.par_max_copied_bytes;
        stats.cumulative_par_balanced_copied_bytes +=
            stats.gc.par_balanced_copied_bytes;
        stats.any_work += any_work;
        stats.no_work += no_work;
        stats.scav_find_work += scav_find_work;
        stats.gc_spin_spin += gc_spin_spin;
        stats.gc_spin_yield += gc_spin_yield;
        stats.mut_spin_spin += mut_spin_spin;
        stats.mut_spin_yield += mut_spin_yield;
    }
    stats.gc_cpu_ns += stats.gc.cpu_ns;
    stats.gc_elapsed_ns += stats.gc.elapsed_ns;

    if (gen == RtsFlags.GcFlags.generations-1) { // major GC?
        stats.major_gcs++;
        if (stats.gc.live_bytes > stats.max_live_bytes) {
            stats.max_live_bytes = stats.gc.live_bytes;
        }
        if (stats.gc.large_objects_bytes > stats.max_large_objects_bytes) {
            stats.max_large_objects_bytes = stats.gc.large_objects_bytes;
        }
        if (stats.gc.compact_bytes > stats.max_compact_bytes) {
            stats.max_compact_bytes = stats.gc.compact_bytes;
        }
        if (stats.gc.slop_bytes > stats.max_slop_bytes) {
            stats.max_slop_bytes = stats.gc.slop_bytes;
        }
        stats.cumulative_live_bytes += stats.gc.live_bytes;
    }

    // -------------------------------------------------
    // Do the more expensive bits only when stats are enabled.

    if (stats_enabled)
    {
        // -------------------------------------------------
        // Emit events to the event log

        // Has to be emitted while all caps stopped for GC, but before GC_END.
        // See trac.haskell.org/ThreadScope/wiki/RTSsummaryEvents
        // for a detailed design rationale of the current setup
        // of GC eventlog events.
        traceEventGcGlobalSync(cap);

        // Emitted before GC_END on all caps, which simplifies tools code.
        traceEventGcStats(cap,
                          CAPSET_HEAP_DEFAULT,
                          stats.gc.gen,
                          stats.gc.copied_bytes,
                          stats.gc.slop_bytes,
                          /* current loss due to fragmentation */
                          (mblocks_allocated * BLOCKS_PER_MBLOCK
                           - n_alloc_blocks) * BLOCK_SIZE,
                          par_n_threads,
                          stats.gc.par_max_copied_bytes,
                          stats.gc.copied_bytes,
                          stats.gc.par_balanced_copied_bytes);

        // Post EVENT_GC_END with the same timestamp as used for stats
        // (though converted from Time=StgInt64 to EventTimestamp=StgWord64).
        // Here, as opposed to other places, the event is emitted on the cap
        // that initiates the GC and external tools expect it to have the same
        // timestamp as used in +RTS -s calculcations.
        traceEventGcEndAtT(cap, TimeToNS(stats.elapsed_ns));

        if (gen == RtsFlags.GcFlags.generations-1) { // major GC?
            traceEventHeapLive(cap,
                               CAPSET_HEAP_DEFAULT,
                               stats.gc.live_bytes);
        }

        // -------------------------------------------------
        // Print GC stats to stdout or a file (+RTS -S/-s)

        if (RtsFlags.GcFlags.giveStats == VERBOSE_GC_STATS) {
            W_ faults = getPageFaults();

            statsPrintf("%9" FMT_Word64 " %9" FMT_Word64 " %9" FMT_Word64,
                        stats.gc.allocated_bytes, stats.gc.copied_bytes,
                        stats.gc.live_bytes);

            statsPrintf(" %6.3f %6.3f %8.3f %8.3f %4"
                        FMT_Word " %4" FMT_Word "  (Gen: %2d)\n",
                    TimeToSecondsDbl(stats.gc.cpu_ns),
                    TimeToSecondsDbl(stats.gc.elapsed_ns),
                    TimeToSecondsDbl(stats.cpu_ns),
                    TimeToSecondsDbl(stats.elapsed_ns),
                    faults - initiating_gct->gc_start_faults,
                        initiating_gct->gc_start_faults - GC_end_faults,
                    gen);

            GC_end_faults = faults;
            statsFlush();
        }


        if (rtsConfig.gcDoneHook != NULL) {
            rtsConfig.gcDoneHook(&stats.gc);
        }

        traceEventHeapSize(cap,
                           CAPSET_HEAP_DEFAULT,
                           mblocks_allocated * MBLOCK_SIZE);
    }
}

/* -----------------------------------------------------------------------------
   Called at the beginning of each Retainer Profiliing
   -------------------------------------------------------------------------- */
#if defined(PROFILING)
void
stat_startRP(void)
{
    Time user, elapsed;
    getProcessTimes( &user, &elapsed );

    RP_start_time = user;
    RPe_start_time = elapsed;
}
#endif /* PROFILING */

/* -----------------------------------------------------------------------------
   Called at the end of each Retainer Profiliing
   -------------------------------------------------------------------------- */

#if defined(PROFILING)
void
stat_endRP(
  uint32_t retainerGeneration,
  int maxStackSize,
  double averageNumVisit)
{
    Time user, elapsed;
    getProcessTimes( &user, &elapsed );

    RP_tot_time += user - RP_start_time;
    RPe_tot_time += elapsed - RPe_start_time;

    fprintf(prof_file, "Retainer Profiling: %d, at %f seconds\n",
      retainerGeneration, mut_user_time_during_RP());
    fprintf(prof_file, "\tMax auxiliary stack size = %u\n", maxStackSize);
    fprintf(prof_file, "\tAverage number of visits per object = %f\n",
            averageNumVisit);
}
#endif /* PROFILING */

/* -----------------------------------------------------------------------------
   Called at the beginning of each heap census
   -------------------------------------------------------------------------- */
#if defined(PROFILING)
void
stat_startHeapCensus(void)
{
    Time user, elapsed;
    getProcessTimes( &user, &elapsed );

    HC_start_time = user;
    HCe_start_time = elapsed;
}
#endif /* PROFILING */

/* -----------------------------------------------------------------------------
   Called at the end of each heap census
   -------------------------------------------------------------------------- */
#if defined(PROFILING)
void
stat_endHeapCensus(void)
{
    Time user, elapsed;
    getProcessTimes( &user, &elapsed );

    HC_tot_time += user - HC_start_time;
    HCe_tot_time += elapsed - HCe_start_time;
}
#endif /* PROFILING */

/* -----------------------------------------------------------------------------
   Called at the end of execution

   NOTE: number of allocations is not entirely accurate: it doesn't
   take into account the few bytes at the end of the heap that
   were left unused when the heap-check failed.
   -------------------------------------------------------------------------- */

#if defined(DEBUG)
#define TICK_VAR_INI(arity) \
  StgInt SLOW_CALLS_##arity = 1; \
  StgInt RIGHT_ARITY_##arity = 1; \
  StgInt TAGGED_PTR_##arity = 0;

TICK_VAR_INI(1)
TICK_VAR_INI(2)

StgInt TOTAL_CALLS=1;
#endif

/* Report the value of a counter */
#define REPORT(counter) \
  { \
    showStgWord64(counter,temp,true/*commas*/); \
    statsPrintf("  (" #counter ")  : %s\n",temp); \
  }

/* Report the value of a counter as a percentage of another counter */
#define REPORT_PCT(counter,countertot) \
  statsPrintf("  (" #counter ") %% of (" #countertot ") : %.1f%%\n", \
              counter*100.0/countertot)

#define TICK_PRINT(arity) \
  REPORT(SLOW_CALLS_##arity); \
  REPORT_PCT(RIGHT_ARITY_##arity,SLOW_CALLS_##arity); \
  REPORT_PCT(TAGGED_PTR_##arity,RIGHT_ARITY_##arity); \
  REPORT(RIGHT_ARITY_##arity); \
  REPORT(TAGGED_PTR_##arity)

#define TICK_PRINT_TOT(arity) \
  statsPrintf("  (SLOW_CALLS_" #arity ") %% of (TOTAL_CALLS) : %.1f%%\n", \
              SLOW_CALLS_##arity * 100.0/TOTAL_CALLS)

/*
Note [RTS Stats Reporting]
==========================

There are currently three reporting functions:
  * report_summary:
      Responsible for producing '+RTS -s' output.
      Will report internal counters if the RTS flag --internal-counters is
      passed. See [Internal Counters Stats]
  * report_machine_readable:
      Responsible for producing '+RTS -t --machine-readable' output.
  * report_one_line:
      Responsible for producing '+RTS -t' output

Stats are accumulated into the global variable 'stats' as the program runs, then
in 'stat_exit' we do the following:
  * Finalise 'stats'. This involves setting final running times and allocations
    that have not yet been accounted for.
  * Create a RTSSummaryStats. This contains all data for reports that is not
    included in stats (because they do not make sense before the program has
    completed) or in a global variable.
  * call the appropriate report_* function, passing the newly constructed
    RTSSummaryStats.

To ensure that the data in the different reports is kept consistent, the
report_* functions should not do any calculation, excepting unit changes and
formatting. If you need to add a new calculated field, add it to
RTSSummaryStats.

*/


static void init_RTSSummaryStats(RTSSummaryStats* sum)
{
    const size_t sizeof_gc_summary_stats =
      RtsFlags.GcFlags.generations * sizeof(GenerationSummaryStats);

    memset(sum, 0, sizeof(RTSSummaryStats));
    sum->gc_summary_stats =
      stgMallocBytes(sizeof_gc_summary_stats,
                     "alloc_RTSSummaryStats.gc_summary_stats");
    memset(sum->gc_summary_stats, 0, sizeof_gc_summary_stats);
}

static void free_RTSSummaryStats(RTSSummaryStats * sum)
{
    stgFree(sum->gc_summary_stats);
    sum->gc_summary_stats = NULL;
}

static void report_summary(const RTSSummaryStats* sum)
{
    // We should do no calculation, other than unit changes and formatting, and
    // we should not use any data from outside of globals, sum and stats
    // here. See Note [RTS Stats Reporting]

    uint32_t g;
    char temp[512];
    showStgWord64(stats.allocated_bytes, temp, true/*commas*/);
    statsPrintf("%16s bytes allocated in the heap\n", temp);

    showStgWord64(stats.copied_bytes, temp, true/*commas*/);
    statsPrintf("%16s bytes copied during GC\n", temp);

    if ( stats.major_gcs > 0 ) {
        showStgWord64(stats.max_live_bytes, temp, true/*commas*/);
        statsPrintf("%16s bytes maximum residency (%" FMT_Word32
                    " sample(s))\n",
                    temp, stats.major_gcs);
    }

    showStgWord64(stats.max_slop_bytes, temp, true/*commas*/);
    statsPrintf("%16s bytes maximum slop\n", temp);

    statsPrintf("%16" FMT_Word64 " MiB total memory in use (%"
                FMT_Word64 " MB lost due to fragmentation)\n\n",
                stats.max_mem_in_use_bytes  / (1024 * 1024),
                sum->fragmentation_bytes / (1024 * 1024));

    /* Print garbage collections in each gen */
    statsPrintf("                                     Tot time (elapsed)  Avg pause  Max pause\n");
    for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
        const GenerationSummaryStats * gen_stats =
            &sum->gc_summary_stats[g];
        statsPrintf("  Gen %2d     %5d colls"
                    ", %5d par   %6.3fs  %6.3fs     %3.4fs    %3.4fs\n",
                    g, // REVIEWERS: this used to be gen->no
                    //, this can't ever be different right?
                    gen_stats->collections,
                    gen_stats->par_collections,
                    TimeToSecondsDbl(gen_stats->cpu_ns),
                    TimeToSecondsDbl(gen_stats->elapsed_ns),
                    TimeToSecondsDbl(gen_stats->avg_pause_ns),
                    TimeToSecondsDbl(gen_stats->max_pause_ns));
    }
    if (RtsFlags.GcFlags.useNonmoving) {
        const int n_major_colls = sum->gc_summary_stats[RtsFlags.GcFlags.generations-1].collections;
        statsPrintf("  Gen  1     %5d syncs"
                    ",                      %6.3fs     %3.4fs    %3.4fs\n",
                    n_major_colls,
                    TimeToSecondsDbl(stats.nonmoving_gc_sync_elapsed_ns),
                    TimeToSecondsDbl(stats.nonmoving_gc_sync_elapsed_ns) / n_major_colls,
                    TimeToSecondsDbl(stats.nonmoving_gc_sync_max_elapsed_ns));
        statsPrintf("  Gen  1      concurrent"
                    ",             %6.3fs  %6.3fs     %3.4fs    %3.4fs\n",
                    TimeToSecondsDbl(stats.nonmoving_gc_cpu_ns),
                    TimeToSecondsDbl(stats.nonmoving_gc_elapsed_ns),
                    TimeToSecondsDbl(stats.nonmoving_gc_elapsed_ns) / n_major_colls,
                    TimeToSecondsDbl(stats.nonmoving_gc_max_elapsed_ns));
    }

    statsPrintf("\n");

#if defined(THREADED_RTS)
    if (RtsFlags.ParFlags.parGcEnabled && sum->work_balance > 0) {
        // See Note [Work Balance]
        statsPrintf("  Parallel GC work balance: "
                    "%.2f%% (serial 0%%, perfect 100%%)\n\n",
                    sum->work_balance * 100);
    }

    statsPrintf("  TASKS: %d "
                "(%d bound, %d peak workers (%d total), using -N%d)\n\n",
                taskCount, sum->bound_task_count,
                peakWorkerCount, workerCount,
                n_capabilities);

    statsPrintf("  SPARKS: %" FMT_Word64
                " (%" FMT_Word " converted, %" FMT_Word " overflowed, %"
                FMT_Word " dud, %" FMT_Word " GC'd, %" FMT_Word " fizzled)\n\n",
                sum->sparks_count,
                sum->sparks.converted, sum->sparks.overflowed,
                sum->sparks.dud, sum->sparks.gcd,
                sum->sparks.fizzled);
#endif

    statsPrintf("  INIT    time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(stats.init_cpu_ns),
                TimeToSecondsDbl(stats.init_elapsed_ns));

    statsPrintf("  MUT     time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(stats.mutator_cpu_ns),
                TimeToSecondsDbl(stats.mutator_elapsed_ns));
    statsPrintf("  GC      time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(stats.gc_cpu_ns),
                TimeToSecondsDbl(stats.gc_elapsed_ns));
    if (RtsFlags.GcFlags.useNonmoving) {
        statsPrintf(
                "  CONC GC time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(stats.nonmoving_gc_cpu_ns),
                TimeToSecondsDbl(stats.nonmoving_gc_elapsed_ns));
    }

#if defined(PROFILING)
    statsPrintf("  RP      time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(sum->rp_cpu_ns),
                TimeToSecondsDbl(sum->rp_elapsed_ns));
    statsPrintf("  PROF    time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(sum->hc_cpu_ns),
                TimeToSecondsDbl(sum->hc_elapsed_ns));
#endif
    statsPrintf("  EXIT    time  %7.3fs  (%7.3fs elapsed)\n",
                TimeToSecondsDbl(sum->exit_cpu_ns),
                TimeToSecondsDbl(sum->exit_elapsed_ns));
    statsPrintf("  Total   time  %7.3fs  (%7.3fs elapsed)\n\n",
                TimeToSecondsDbl(stats.cpu_ns),
                TimeToSecondsDbl(stats.elapsed_ns));
#if !defined(THREADED_RTS)
    statsPrintf("  %%GC     time     %5.1f%%  (%.1f%% elapsed)\n\n",
                sum->gc_cpu_percent * 100,
                sum->gc_elapsed_percent * 100);
#endif

    showStgWord64(sum->alloc_rate, temp, true/*commas*/);

    statsPrintf("  Alloc rate    %s bytes per MUT second\n\n", temp);

    statsPrintf("  Productivity %5.1f%% of total user, "
                "%.1f%% of total elapsed\n\n",
                sum->productivity_cpu_percent * 100,
                sum->productivity_elapsed_percent * 100);

    // See Note [Internal Counter Stats] for a description of the
    // following counters. If you add a counter here, please remember
    // to update the Note.
    if (RtsFlags.MiscFlags.internalCounters) {
#if defined(THREADED_RTS) && defined(PROF_SPIN)
        const int32_t col_width[] = {4, -30, 14, 14};
        statsPrintf("Internal Counters:\n");
        statsPrintf("%*s" "%*s" "%*s" "%*s" "\n"
                    , col_width[0], ""
                    , col_width[1], "SpinLock"
                    , col_width[2], "Spins"
                    , col_width[3], "Yields");
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "gc_alloc_block_sync"
                    , col_width[2], gc_alloc_block_sync.spin
                    , col_width[3], gc_alloc_block_sync.yield);
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "gc_spin"
                    , col_width[2], stats.gc_spin_spin
                    , col_width[3], stats.gc_spin_yield);
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "mut_spin"
                    , col_width[2], stats.mut_spin_spin
                    , col_width[3], stats.mut_spin_yield);
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*s\n"
                    , col_width[0], ""
                    , col_width[1], "whitehole_gc"
                    , col_width[2], whitehole_gc_spin
                    , col_width[3], "n/a");
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*s\n"
                    , col_width[0], ""
                    , col_width[1], "whitehole_threadPaused"
                    , col_width[2], whitehole_threadPaused_spin
                    , col_width[3], "n/a");
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*s\n"
                    , col_width[0], ""
                    , col_width[1], "whitehole_executeMessage"
                    , col_width[2], whitehole_executeMessage_spin
                    , col_width[3], "n/a");
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "whitehole_lockClosure"
                    , col_width[2], whitehole_lockClosure_spin
                    , col_width[3], whitehole_lockClosure_yield);
        // waitForGcThreads isn't really spin-locking(see the function)
        // but these numbers still seem useful.
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "waitForGcThreads"
                    , col_width[2], waitForGcThreads_spin
                    , col_width[3], waitForGcThreads_yield);

        for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
            int prefix_length = 0;
            statsPrintf("%*s" "gen[%" FMT_Word32 "%n",
                        col_width[0], "", g, &prefix_length);
            prefix_length -= col_width[0];
            int suffix_length = col_width[1] + prefix_length;
            suffix_length =
                  suffix_length > 0 ? col_width[1] : suffix_length;

            statsPrintf("%*s" "%*" FMT_Word64 "%*" FMT_Word64 "\n"
                        , suffix_length, "].sync"
                        , col_width[2], generations[g].sync.spin
                        , col_width[3], generations[g].sync.yield);
        }
        statsPrintf("\n");
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "any_work"
                    , col_width[2], stats.any_work);
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "no_work"
                    , col_width[2], stats.no_work);
        statsPrintf("%*s" "%*s" "%*" FMT_Word64 "\n"
                    , col_width[0], ""
                    , col_width[1], "scav_find_work"
                    , col_width[2], stats.scav_find_work);
#elif defined(THREADED_RTS) // THREADED_RTS && PROF_SPIN
        statsPrintf("Internal Counters require the RTS to be built "
                "with PROF_SPIN"); // PROF_SPIN is not #defined here
#else // THREADED_RTS
        statsPrintf("Internal Counters require the threaded RTS");
#endif
    }
}

static void report_machine_readable (const RTSSummaryStats * sum)
{
    // We should do no calculation, other than unit changes and formatting, and
    // we should not use any data from outside of globals, sum and stats
    // here. See Note [RTS Stats Reporting]
    uint32_t g;

#define MR_STAT(field_name,format,value) \
    statsPrintf(" ,(\"" field_name "\", \"%" format "\")\n", value)
#define MR_STAT_GEN(gen,field_name,format,value) \
    statsPrintf(" ,(\"gen_%" FMT_Word32 "_" field_name "\", \"%" \
      format "\")\n", g, value)

    // These first values are for backwards compatibility.
    // Some of these first fields are duplicated with more machine-readable
    // names, or to match the name in RtsStats.

    // we don't use for the first field helper macro here because the prefix is
    // different
    statsPrintf(" [(\"%s\", \"%" FMT_Word64 "\")\n", "bytes allocated",
                stats.allocated_bytes);
    MR_STAT("num_GCs", FMT_Word32, stats.gcs);
    MR_STAT("average_bytes_used", FMT_Word64, sum->average_bytes_used);
    MR_STAT("max_bytes_used", FMT_Word64, stats.max_live_bytes);
    MR_STAT("num_byte_usage_samples", FMT_Word32, stats.major_gcs);
    MR_STAT("peak_megabytes_allocated", FMT_Word64,
      stats.max_mem_in_use_bytes / (1024 * 1024));

    MR_STAT("init_cpu_seconds", "f", TimeToSecondsDbl(stats.init_cpu_ns));
    MR_STAT("init_wall_seconds", "f", TimeToSecondsDbl(stats.init_elapsed_ns));
    MR_STAT("mut_cpu_seconds", "f", TimeToSecondsDbl(stats.mutator_cpu_ns));
    MR_STAT("mut_wall_seconds", "f",
            TimeToSecondsDbl(stats.mutator_elapsed_ns));
    MR_STAT("GC_cpu_seconds", "f", TimeToSecondsDbl(stats.gc_cpu_ns));
    MR_STAT("GC_wall_seconds", "f", TimeToSecondsDbl(stats.gc_elapsed_ns));

    // end backward compatibility

    // First, the rest of the times

    MR_STAT("exit_cpu_seconds", "f", TimeToSecondsDbl(sum->exit_cpu_ns));
    MR_STAT("exit_wall_seconds", "f", TimeToSecondsDbl(sum->exit_elapsed_ns));
#if defined(PROFILING)
    MR_STAT("rp_cpu_seconds", "f", TimeToSecondsDbl(sum->rp_cpu_ns));
    MR_STAT("rp_wall_seconds", "f", TimeToSecondsDbl(sum->rp_elapsed_ns));
    MR_STAT("hc_cpu_seconds", "f", TimeToSecondsDbl(sum->hc_cpu_ns));
    MR_STAT("hc_wall_seconds", "f", TimeToSecondsDbl(sum->hc_elapsed_ns));
#endif
    MR_STAT("total_cpu_seconds", "f", TimeToSecondsDbl(stats.cpu_ns));
    MR_STAT("total_wall_seconds", "f",
            TimeToSecondsDbl(stats.elapsed_ns));

    // next, the remainder of the fields of RTSStats, except internal counters

    // The first two are duplicates of those above, but have more machine
    // readable names that match the field names in RTSStats.


    // gcs has been done as num_GCs above
    MR_STAT("major_gcs", FMT_Word32, stats.major_gcs);
    MR_STAT("allocated_bytes", FMT_Word64, stats.allocated_bytes);
    MR_STAT("max_live_bytes", FMT_Word64, stats.max_live_bytes);
    MR_STAT("max_large_objects_bytes", FMT_Word64,
            stats.max_large_objects_bytes);
    MR_STAT("max_compact_bytes", FMT_Word64, stats.max_compact_bytes);
    MR_STAT("max_slop_bytes", FMT_Word64, stats.max_slop_bytes);
    // This duplicates, except for unit, peak_megabytes_allocated above
    MR_STAT("max_mem_in_use_bytes", FMT_Word64, stats.max_mem_in_use_bytes);
    MR_STAT("cumulative_live_bytes", FMT_Word64, stats.cumulative_live_bytes);
    MR_STAT("copied_bytes", FMT_Word64, stats.copied_bytes);
    MR_STAT("par_copied_bytes", FMT_Word64, stats.par_copied_bytes);
    MR_STAT("cumulative_par_max_copied_bytes", FMT_Word64,
            stats.cumulative_par_max_copied_bytes);
    MR_STAT("cumulative_par_balanced_copied_bytes", FMT_Word64,
            stats.cumulative_par_balanced_copied_bytes);

    // next, the computed fields in RTSSummaryStats
#if !defined(THREADED_RTS) // THREADED_RTS
    MR_STAT("gc_cpu_percent", "f", sum->gc_cpu_percent);
    MR_STAT("gc_wall_percent", "f", sum->gc_cpu_percent);
#endif
    MR_STAT("fragmentation_bytes", FMT_Word64, sum->fragmentation_bytes);
    // average_bytes_used is done above
    MR_STAT("alloc_rate", FMT_Word64, sum->alloc_rate);
    MR_STAT("productivity_cpu_percent", "f", sum->productivity_cpu_percent);
    MR_STAT("productivity_wall_percent", "f",
            sum->productivity_elapsed_percent);

    // next, the THREADED_RTS fields in RTSSummaryStats

#if defined(THREADED_RTS)
    MR_STAT("bound_task_count", FMT_Word32, sum->bound_task_count);
    MR_STAT("sparks_count", FMT_Word64, sum->sparks_count);
    MR_STAT("sparks_converted", FMT_Word, sum->sparks.converted);
    MR_STAT("sparks_overflowed", FMT_Word, sum->sparks.overflowed);
    MR_STAT("sparks_dud ", FMT_Word, sum->sparks.dud);
    MR_STAT("sparks_gcd", FMT_Word, sum->sparks.gcd);
    MR_STAT("sparks_fizzled", FMT_Word, sum->sparks.fizzled);
    MR_STAT("work_balance", "f", sum->work_balance);

    // next, globals (other than internal counters)
    MR_STAT("n_capabilities", FMT_Word32, n_capabilities);
    MR_STAT("task_count", FMT_Word32, taskCount);
    MR_STAT("peak_worker_count", FMT_Word32, peakWorkerCount);
    MR_STAT("worker_count", FMT_Word32, workerCount);

    // next, internal counters
#if defined(PROF_SPIN)
    MR_STAT("gc_alloc_block_sync_spin", FMT_Word64, gc_alloc_block_sync.spin);
    MR_STAT("gc_alloc_block_sync_yield", FMT_Word64,
            gc_alloc_block_sync.yield);
    MR_STAT("gc_alloc_block_sync_spin", FMT_Word64, gc_alloc_block_sync.spin);
    MR_STAT("gc_spin_spin", FMT_Word64, stats.gc_spin_spin);
    MR_STAT("gc_spin_yield", FMT_Word64, stats.gc_spin_yield);
    MR_STAT("mut_spin_spin", FMT_Word64, stats.mut_spin_spin);
    MR_STAT("mut_spin_yield", FMT_Word64, stats.mut_spin_yield);
    MR_STAT("waitForGcThreads_spin", FMT_Word64, waitForGcThreads_spin);
    MR_STAT("waitForGcThreads_yield", FMT_Word64,
            waitForGcThreads_yield);
    MR_STAT("whitehole_gc_spin", FMT_Word64, whitehole_gc_spin);
    MR_STAT("whitehole_lockClosure_spin", FMT_Word64,
            whitehole_lockClosure_spin);
    MR_STAT("whitehole_lockClosure_yield", FMT_Word64,
            whitehole_lockClosure_yield);
    MR_STAT("whitehole_executeMessage_spin", FMT_Word64,
            whitehole_executeMessage_spin);
    MR_STAT("whitehole_threadPaused_spin", FMT_Word64,
            whitehole_threadPaused_spin);
    MR_STAT("any_work", FMT_Word64,
            stats.any_work);
    MR_STAT("no_work", FMT_Word64,
            stats.no_work);
    MR_STAT("scav_find_work", FMT_Word64,
            stats.scav_find_work);
#endif // PROF_SPIN
#endif // THREADED_RTS

    // finally, per-generation stats. Named as, for example for generation 0,
    // gen_0_collections
    for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
        const GenerationSummaryStats* gc_sum = &sum->gc_summary_stats[g];
        MR_STAT_GEN(g, "collections", FMT_Word32, gc_sum->collections);
        MR_STAT_GEN(g, "par_collections", FMT_Word32, gc_sum->par_collections);
        MR_STAT_GEN(g, "cpu_seconds", "f", TimeToSecondsDbl(gc_sum->cpu_ns));
        MR_STAT_GEN(g, "wall_seconds", "f",
                    TimeToSecondsDbl(gc_sum->elapsed_ns));
        MR_STAT_GEN(g, "max_pause_seconds", "f",
                    TimeToSecondsDbl(gc_sum->max_pause_ns));
        MR_STAT_GEN(g, "avg_pause_seconds", "f",
                    TimeToSecondsDbl(gc_sum->avg_pause_ns));
#if defined(THREADED_RTS) && defined(PROF_SPIN)
        MR_STAT_GEN(g, "sync_spin", FMT_Word64, gc_sum->sync_spin);
        MR_STAT_GEN(g, "sync_yield", FMT_Word64, gc_sum->sync_yield);
#endif
    }
    // non-moving collector statistics
    if (RtsFlags.GcFlags.useNonmoving) {
        const int n_major_colls = sum->gc_summary_stats[RtsFlags.GcFlags.generations-1].collections;
        MR_STAT("nonmoving_sync_wall_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_sync_elapsed_ns));
        MR_STAT("nonmoving_sync_max_pause_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_sync_max_elapsed_ns));
        MR_STAT("nonmoving_sync_avg_pause_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_sync_elapsed_ns) / n_major_colls);

        MR_STAT("nonmoving_concurrent_cpu_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_cpu_ns));
        MR_STAT("nonmoving_concurrent_wall_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_elapsed_ns));
        MR_STAT("nonmoving_concurrent_max_pause_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_max_elapsed_ns));
        MR_STAT("nonmoving_concurrent_avg_pause_seconds", "f",
                TimeToSecondsDbl(stats.nonmoving_gc_elapsed_ns) / n_major_colls);
    }


    statsPrintf(" ]\n");
}

static void report_one_line(const RTSSummaryStats * sum)
{
    // We should do no calculation, other than unit changes and formatting, and
    // we should not use any data from outside of globals, sum and stats
    // here. See Note [RTS Stats Reporting]

    /* print the long long separately to avoid bugginess on mingwin (2001-07-02,
    mingw-0.5) */
    statsPrintf("<<ghc: %" FMT_Word64 " bytes, "
                "%" FMT_Word32 " GCs, "
                "%" FMT_Word64 "/%" FMT_Word64 " avg/max bytes residency "
                "(%" FMT_Word32 " samples), "
                "%" FMT_Word64 "M in use, "
                "%.3f INIT (%.3f elapsed), "
                "%.3f MUT (%.3f elapsed), "
                "%.3f GC (%.3f elapsed) :ghc>>\n",
                stats.allocated_bytes,
                stats.gcs,
                sum->average_bytes_used,
                stats.max_live_bytes,
                stats.major_gcs,
                stats.max_mem_in_use_bytes / (1024 * 1024),
                TimeToSecondsDbl(stats.init_cpu_ns),
                TimeToSecondsDbl(stats.init_elapsed_ns),
                TimeToSecondsDbl(stats.mutator_cpu_ns),
                TimeToSecondsDbl(stats.mutator_elapsed_ns),
                TimeToSecondsDbl(stats.gc_cpu_ns),
                TimeToSecondsDbl(stats.gc_elapsed_ns));
}

void
stat_exit (void)
{
    RTSSummaryStats sum;
    init_RTSSummaryStats(&sum);

    if (RtsFlags.GcFlags.giveStats != NO_GC_STATS) {
        // First we tidy the times in stats, and populate the times in sum.
        // In particular, we adjust the gc_* time in stats to remove
        // profiling times.
        {
            Time now_cpu_ns, now_elapsed_ns;
            getProcessTimes(&now_cpu_ns, &now_elapsed_ns);

            stats.cpu_ns = now_cpu_ns - start_init_cpu;
            stats.elapsed_ns = now_elapsed_ns - start_init_elapsed;
            /* avoid divide by zero if stats.total_cpu_ns is measured as 0.00
               seconds -- SDM */
            if (stats.cpu_ns <= 0) { stats.cpu_ns = 1; }
            if (stats.elapsed_ns <= 0) { stats.elapsed_ns = 1; }

#if defined(PROFILING)
            sum.rp_cpu_ns = RP_tot_time;
            sum.rp_elapsed_ns = RPe_tot_time;
            sum.hc_cpu_ns = HC_tot_time;
            sum.hc_elapsed_ns = HCe_tot_time;
#endif // PROFILING

            // We do a GC during the EXIT phase. We'll attribute the cost of
            // that to GC instead of EXIT, so carefully subtract it from the
            // EXIT time.
            // Note that exit_gc includes RP and HC for the exit GC too.
            Time exit_gc_cpu     = stats.gc_cpu_ns - start_exit_gc_cpu;
            Time exit_gc_elapsed = stats.gc_elapsed_ns - start_exit_gc_elapsed;

            ASSERT(exit_gc_elapsed > 0);

            sum.exit_cpu_ns     = end_exit_cpu
                                      - start_exit_cpu
                                      - exit_gc_cpu;
            sum.exit_elapsed_ns = end_exit_elapsed
                                       - start_exit_elapsed
                                       - exit_gc_elapsed;

            ASSERT(sum.exit_elapsed_ns >= 0);

            stats.mutator_cpu_ns     = start_exit_cpu
                                 - end_init_cpu
                                 - (stats.gc_cpu_ns - exit_gc_cpu)
                                 - stats.nonmoving_gc_cpu_ns;
            stats.mutator_elapsed_ns = start_exit_elapsed
                                 - end_init_elapsed
                                 - (stats.gc_elapsed_ns - exit_gc_elapsed);

            ASSERT(stats.mutator_elapsed_ns >= 0);

            if (stats.mutator_cpu_ns < 0) { stats.mutator_cpu_ns = 0; }

            // The subdivision of runtime into INIT/EXIT/GC/MUT is just adding
            // and subtracting, so the parts should add up to the total exactly.
            // Note that stats->total_ns is captured a tiny bit later than
            // end_exit_elapsed, so we don't use it here.
            ASSERT(stats.init_elapsed_ns // INIT
                   + stats.mutator_elapsed_ns // MUT
                   + stats.gc_elapsed_ns // GC
                   + sum.exit_elapsed_ns // EXIT
                   == end_exit_elapsed - start_init_elapsed);

            // heapCensus() is called by the GC, so RP and HC time are
            // included in the GC stats.  We therefore subtract them to
            // obtain the actual GC cpu time.
            Time prof_cpu     = sum.rp_cpu_ns + sum.hc_cpu_ns;
            Time prof_elapsed = sum.rp_elapsed_ns + sum.hc_elapsed_ns;

            stats.gc_cpu_ns      -=  prof_cpu;
            stats.gc_elapsed_ns  -=  prof_elapsed;

            // This assertion is probably not necessary; make sure the
            // subdivision with PROF also makes sense
            ASSERT(stats.init_elapsed_ns // INIT
                   + stats.mutator_elapsed_ns // MUT
                   + stats.gc_elapsed_ns // GC
                   + sum.exit_elapsed_ns // EXIT
                   + (sum.rp_elapsed_ns + sum.hc_elapsed_ns) // PROF
                   == end_exit_elapsed - start_init_elapsed);
        }

        // REVIEWERS: it's not clear to me why the following isn't done in
        // stat_endGC of the last garbage collection?

        // We account for the last garbage collection
        {
            uint64_t tot_alloc_bytes = calcTotalAllocated() * sizeof(W_);
            stats.gc.allocated_bytes = tot_alloc_bytes - stats.allocated_bytes;
            stats.allocated_bytes = tot_alloc_bytes;
            if (RtsFlags.GcFlags.giveStats >= VERBOSE_GC_STATS) {
                statsPrintf("%9" FMT_Word " %9.9s %9.9s",
                            (W_)stats.gc.allocated_bytes, "", "");
                statsPrintf(" %6.3f %6.3f\n\n", 0.0, 0.0);
            }
        }

        // We populate the remainder (non-time elements) of sum
        {
    #if defined(THREADED_RTS)
            sum.bound_task_count = taskCount - workerCount;

            for (uint32_t i = 0; i < n_capabilities; i++) {
                sum.sparks.created   += capabilities[i]->spark_stats.created;
                sum.sparks.dud       += capabilities[i]->spark_stats.dud;
                sum.sparks.overflowed+=
                  capabilities[i]->spark_stats.overflowed;
                sum.sparks.converted +=
                  capabilities[i]->spark_stats.converted;
                sum.sparks.gcd       += capabilities[i]->spark_stats.gcd;
                sum.sparks.fizzled   += capabilities[i]->spark_stats.fizzled;
            }

            sum.sparks_count = sum.sparks.created
                + sum.sparks.dud
                + sum.sparks.overflowed;

            if (RtsFlags.ParFlags.parGcEnabled && stats.par_copied_bytes > 0) {
                // See Note [Work Balance]
                sum.work_balance =
                    (double)stats.cumulative_par_balanced_copied_bytes
                    / (double)stats.par_copied_bytes;
            } else {
                sum.work_balance = 0;
            }


    #else // THREADED_RTS
            sum.gc_cpu_percent     = stats.gc_cpu_ns
                                  / stats.cpu_ns;
            sum.gc_elapsed_percent = stats.gc_elapsed_ns
                                  / stats.elapsed_ns;
    #endif // THREADED_RTS

            sum.fragmentation_bytes =
                (uint64_t)(peak_mblocks_allocated
                         * BLOCKS_PER_MBLOCK
                         * BLOCK_SIZE_W
                         - hw_alloc_blocks * BLOCK_SIZE_W)
                / (uint64_t)sizeof(W_);

            sum.average_bytes_used = stats.major_gcs == 0 ? 0 :
                 stats.cumulative_live_bytes/stats.major_gcs,

            sum.alloc_rate = stats.mutator_cpu_ns == 0 ? 0 :
                (uint64_t)((double)stats.allocated_bytes
                / TimeToSecondsDbl(stats.mutator_cpu_ns));

            // REVIEWERS: These two values didn't used to include the exit times
            sum.productivity_cpu_percent =
                TimeToSecondsDbl(stats.cpu_ns
                                - stats.gc_cpu_ns
                                - stats.init_cpu_ns
                                - sum.exit_cpu_ns)
                / TimeToSecondsDbl(stats.cpu_ns);

            ASSERT(sum.productivity_cpu_percent >= 0);

            sum.productivity_elapsed_percent =
                TimeToSecondsDbl(stats.elapsed_ns
                                - stats.gc_elapsed_ns
                                - stats.init_elapsed_ns
                                - sum.exit_elapsed_ns)
                / TimeToSecondsDbl(stats.elapsed_ns);

            ASSERT(sum.productivity_elapsed_percent >= 0);

            for(uint32_t g = 0; g < RtsFlags.GcFlags.generations; ++g) {
                const generation* gen = &generations[g];
                GenerationSummaryStats* gen_stats = &sum.gc_summary_stats[g];
                gen_stats->collections = gen->collections;
                gen_stats->par_collections = gen->par_collections;
                gen_stats->cpu_ns = GC_coll_cpu[g];
                gen_stats->elapsed_ns = GC_coll_elapsed[g];
                gen_stats->max_pause_ns = GC_coll_max_pause[g];
                gen_stats->avg_pause_ns = gen->collections == 0 ?
                    0 : (GC_coll_elapsed[g] / gen->collections);
    #if defined(THREADED_RTS) && defined(PROF_SPIN)
                gen_stats->sync_spin = gen->sync.spin;
                gen_stats->sync_yield = gen->sync.yield;
    #endif // PROF_SPIN
            }
        }

        // Now we generate the report
        if (RtsFlags.GcFlags.giveStats >= SUMMARY_GC_STATS) {
            report_summary(&sum);
        }

        if (RtsFlags.GcFlags.giveStats == ONELINE_GC_STATS) {
            if (RtsFlags.MiscFlags.machineReadable) {
                report_machine_readable(&sum);
            }
            else {
                report_one_line(&sum);
            }
        }

        statsFlush();
        statsClose();
    }

    free_RTSSummaryStats(&sum);

    if (GC_coll_cpu) {
      stgFree(GC_coll_cpu);
      GC_coll_cpu = NULL;
    }
    if (GC_coll_elapsed) {
      stgFree(GC_coll_elapsed);
      GC_coll_elapsed = NULL;
    }
    if (GC_coll_max_pause) {
      stgFree(GC_coll_max_pause);
      GC_coll_max_pause = NULL;
    }
}

/* Note [Work Balance]
----------------------
Work balance is a measure of how evenly the work done during parallel garbage
collection is spread across threads. To compute work balance we must take care
to account for the number of GC threads changing between GCs. The statistics we
track must have the number of GC threads "integrated out".

We accumulate two values from each garbage collection:
* par_copied: is a measure of the total work done during parallel garbage
  collection
* par_balanced_copied: is a measure of the balanced work done
  during parallel garbage collection.

par_copied is simple to compute, but par_balanced_copied_bytes is somewhat more
complicated:

For a given garbage collection:
Let gc_copied := total copies during the gc
    gc_copied_i := copies by the ith thread during the gc
    num_gc_threads := the number of threads participating in the gc
    balance_limit := (gc_copied / num_gc_threads)

If we were to graph gc_copied_i, sorted from largest to smallest we would see
something like:

       |X
  ^    |X X
  |    |X X X            X: unbalanced copies
copies |-----------      Y: balanced copies by the busiest GC thread
       |Y Z Z            Z: other balanced copies
       |Y Z Z Z
       |Y Z Z Z Z
       |Y Z Z Z Z Z
       |===========
       |1 2 3 4 5 6
          i ->

where the --- line is at balance_limit. Balanced copies are those under the ---
line, i.e. the area of the Ys and Zs. Note that the area occupied by the Ys will
always equal balance_limit. Completely balanced gc has every thread copying
balance_limit and a completely unbalanced gc has a single thread copying
gc_copied.

One could define par_balance_copied as the areas of the Ys and Zs in the graph
above, however we would like the ratio of (par_balance_copied / gc_copied) to
range from 0 to 1, so that work_balance will be a nice percentage, also ranging
from 0 to 1. We therefore define par_balanced_copied as:

                                                        (  num_gc_threads  )
{Sum[Min(gc_copied_i,balance_limit)] - balance_limit} * (------------------)
  i                                                     (num_gc_threads - 1)
                                          vvv                  vvv
                                           S                    T

Where the S and T terms serve to remove the area of the Ys, and
to normalize the result to lie between 0 and gc_copied.

Note that the implementation orders these operations differently to minimize
error due to integer rounding.

Then cumulative work balance is computed as
(cumulative_par_balanced_copied_bytes / par_copied_byes)

Previously, cumulative work balance was computed as:

(cumulative_par_max_copied_bytes)
(-------------------------------) - 1
(       par_copied_bytes        )
-------------------------------------
        (n_capabilities - 1)

This was less accurate than the current method, and invalid whenever a garbage
collection had occurred with num_gc_threads /= n_capabilities; which can happen
when setNumCapabilities is called, when -qn is passed as an RTS option, or when
the number of gc threads is limited to the number of cores.
See #13830
*/

/*
Note [Internal Counter Stats]
-----------------------------
What do the counts at the end of a '+RTS -s --internal-counters' report mean?
They are detailed below. Most of these counters are used by multiple threads
with no attempt at synchronisation. This means that reported values  may be
lower than the true value and this becomes more likely and more severe as
contention increases.

The first counters are for various SpinLock-like constructs in the RTS. See
Spinlock.h for the definition of a SpinLock. We maintain up two counters per
SpinLock:
* spin: The number of busy-spins over the length of the program.
* yield: The number of times the SpinLock spun SPIN_COUNT times without success
         and called yieldThread().
Not all of these are actual SpinLocks, see the details below.

Actual SpinLocks:
* gc_alloc_block:
    This SpinLock protects the block allocator and free list manager. See
    BlockAlloc.c.
* gc_spin and mut_spin:
    These SpinLocks are used to herd gc worker threads during parallel garbage
    collection. See gcWorkerThread, wakeup_gc_threads and releaseGCThreads.
* gen[g].sync:
    These SpinLocks, one per generation, protect the generations[g] data
    structure during garbage collection.

waitForGcThreads:
  These counters are incremented while we wait for all threads to be ready
  for a parallel garbage collection. We yield more than we spin in this case.

In several places in the runtime we must take a lock on a closure. To do this,
we replace its info table with stg_WHITEHOLE_info, spinning if it is already
a white-hole. Sometimes we yieldThread() if we spin too long, sometimes we
don't. We count these white-hole spins and include them in the SpinLocks table.
If a particular loop does not yield, we put "n/a" in the table. They are named
for the function that has the spinning loop except that several loops in the
garbage collector accumulate into whitehole_gc.
TODO: Should these counters be more or less granular?

white-hole spin counters:
* whitehole_gc
* whitehole_lockClosure
* whitehole_executeMessage
* whitehole_threadPaused


We count the number of calls of several functions in the parallel garbage
collector.

Parallel garbage collector counters:
* any_work:
    A cheap function called whenever a gc_thread is ready for work. Does
    not do any work.
* no_work:
    Incremented whenever any_work finds no work.
* scav_find_work:
    Called to do work when any_work return true.

*/

/* -----------------------------------------------------------------------------
   stat_describe_gens

   Produce some detailed info on the state of the generational GC.
   -------------------------------------------------------------------------- */
void
statDescribeGens(void)
{
  uint32_t g, mut, lge, compacts, i;
  W_ gen_slop;
  W_ tot_live, tot_slop;
  W_ gen_live, gen_blocks;
  bdescr *bd;
  generation *gen;

  debugBelch(
"----------------------------------------------------------------------\n"
"  Gen     Max  Mut-list  Blocks    Large  Compacts      Live      Slop\n"
"       Blocks     Bytes          Objects                              \n"
"----------------------------------------------------------------------\n");

  tot_live = 0;
  tot_slop = 0;

  for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
      gen = &generations[g];

      for (bd = gen->large_objects, lge = 0; bd; bd = bd->link) {
          lge++;
      }

      for (bd = gen->compact_objects, compacts = 0; bd; bd = bd->link) {
          compacts++;
      }

      gen_live   = genLiveWords(gen);
      gen_blocks = genLiveBlocks(gen);

      mut = 0;
      for (i = 0; i < n_capabilities; i++) {
          mut += countOccupied(capabilities[i]->mut_lists[g]);

          // Add the pinned object block.
          bd = capabilities[i]->pinned_object_block;
          if (bd != NULL) {
              gen_live   += bd->free - bd->start;
              gen_blocks += bd->blocks;
          }

          gen_live   += gcThreadLiveWords(i,g);
          gen_blocks += gcThreadLiveBlocks(i,g);
      }

      debugBelch("%5d %7" FMT_Word " %9d", g, (W_)gen->max_blocks, mut);

      gen_slop = gen_blocks * BLOCK_SIZE_W - gen_live;

      debugBelch("%8" FMT_Word " %8d  %8d %9" FMT_Word " %9" FMT_Word "\n",
                 gen_blocks, lge, compacts, gen_live*(W_)sizeof(W_),
                 gen_slop*(W_)sizeof(W_));
      tot_live += gen_live;
      tot_slop += gen_slop;
  }
  debugBelch("----------------------------------------------------------------------\n");
  debugBelch("%51s%9" FMT_Word " %9" FMT_Word "\n",
             "",tot_live*(W_)sizeof(W_),tot_slop*(W_)sizeof(W_));
  debugBelch("----------------------------------------------------------------------\n");
  debugBelch("\n");
}

/* -----------------------------------------------------------------------------
   Stats available via a programmatic interface, so eg. GHCi can time
   each compilation and expression evaluation.
   -------------------------------------------------------------------------- */

uint64_t getAllocations( void )
{
    return stats.allocated_bytes;
}

int getRTSStatsEnabled( void )
{
    return RtsFlags.GcFlags.giveStats != NO_GC_STATS;
}

void getRTSStats( RTSStats *s )
{
    Time current_elapsed = 0;
    Time current_cpu = 0;

    *s = stats;

    getProcessTimes(&current_cpu, &current_elapsed);
    s->cpu_ns = current_cpu - end_init_cpu;
    s->elapsed_ns = current_elapsed - end_init_elapsed;

    s->mutator_cpu_ns = current_cpu - end_init_cpu - stats.gc_cpu_ns -
        stats.nonmoving_gc_cpu_ns;
    s->mutator_elapsed_ns = current_elapsed - end_init_elapsed -
        stats.gc_elapsed_ns;
}

/* -----------------------------------------------------------------------------
   Dumping stuff in the stats file, or via the debug message interface
   -------------------------------------------------------------------------- */

void
statsPrintf( char *s, ... )
{
    FILE *sf = RtsFlags.GcFlags.statsFile;
    va_list ap;

    va_start(ap,s);
    if (sf == NULL) {
        vdebugBelch(s,ap);
    } else {
        vfprintf(sf, s, ap);
    }
    va_end(ap);
}

static void
statsFlush( void )
{
    FILE *sf = RtsFlags.GcFlags.statsFile;
    if (sf != NULL) {
        fflush(sf);
    }
}

static void
statsClose( void )
{
    FILE *sf = RtsFlags.GcFlags.statsFile;
    if (sf != NULL) {
        fclose(sf);
    }
}