summaryrefslogtreecommitdiff
path: root/rts/Stats.c
blob: fcca405801f15d7d9bcad09add4427b4812087cd (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
/* -----------------------------------------------------------------------------
 *
 * (c) The GHC Team, 1998-2005
 *
 * Statistics and timing-related functions.
 *
 * ---------------------------------------------------------------------------*/

#include "Rts.h"
#include "RtsFlags.h"
#include "RtsUtils.h"
#include "MBlock.h"
#include "Storage.h"
#include "Schedule.h"
#include "Stats.h"
#include "ParTicky.h"                       /* ToDo: move into Rts.h */
#include "Profiling.h"
#include "GetTime.h"

#if USE_PAPI
#include "Papi.h"
#endif

/* huh? */
#define BIG_STRING_LEN              512

#define TICK_TO_DBL(t) ((double)(t) / TICKS_PER_SECOND)

static Ticks ElapsedTimeStart = 0;

static Ticks InitUserTime     = 0;
static Ticks InitElapsedTime  = 0;
static Ticks InitElapsedStamp = 0;

static Ticks MutUserTime      = 0;
static Ticks MutElapsedTime   = 0;
static Ticks MutElapsedStamp  = 0;

static Ticks ExitUserTime     = 0;
static Ticks ExitElapsedTime  = 0;

static ullong GC_tot_alloc        = 0;
static ullong GC_tot_copied       = 0;

static Ticks GC_start_time = 0,  GC_tot_time  = 0;  /* User GC Time */
static Ticks GCe_start_time = 0, GCe_tot_time = 0;  /* Elapsed GC time */

#ifdef PROFILING
static Ticks RP_start_time  = 0, RP_tot_time  = 0;  /* retainer prof user time */
static Ticks RPe_start_time = 0, RPe_tot_time = 0;  /* retainer prof elap time */

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

#ifdef PROFILING
#define PROF_VAL(x)   (x)
#else
#define PROF_VAL(x)   0
#endif

static lnat MaxResidency = 0;     // in words; for stats only
static lnat AvgResidency = 0;
static lnat ResidencySamples = 0; // for stats only

static lnat GC_start_faults = 0, GC_end_faults = 0;

static Ticks *GC_coll_times;
static Ticks *GC_coll_etimes;

static void statsFlush( void );
static void statsClose( void );

Ticks stat_getElapsedGCTime(void)
{
    return GCe_tot_time;
}

Ticks stat_getElapsedTime(void)
{
    return getProcessElapsedTime() - ElapsedTimeStart;
}

/* mut_user_time_during_GC() and mut_user_time()
 *
 * The former function can be used to get the current mutator time
 * *during* a GC, i.e. between stat_startGC and stat_endGC.  This is
 * used in the heap profiler for accurately time stamping the heap
 * sample.  
 *
 * ATTENTION: mut_user_time_during_GC() relies on GC_start_time being 
 *	      defined in stat_startGC() - to minimise system calls, 
 *	      GC_start_time is, however, only defined when really needed (check
 *	      stat_startGC() for details)
 */
double
mut_user_time_during_GC( void )
{
  return TICK_TO_DBL(GC_start_time - GC_tot_time - PROF_VAL(RP_tot_time + HC_tot_time));
}

double
mut_user_time( void )
{
    Ticks user;
    user = getProcessCPUTime();
    return TICK_TO_DBL(user - GC_tot_time - PROF_VAL(RP_tot_time + HC_tot_time));
}

#ifdef PROFILING
/*
  mut_user_time_during_RP() is similar to mut_user_time_during_GC();
  it returns the MUT time during retainer profiling.
  The same is for mut_user_time_during_HC();
 */
double
mut_user_time_during_RP( void )
{
  return TICK_TO_DBL(RP_start_time - GC_tot_time - RP_tot_time - HC_tot_time);
}

double
mut_user_time_during_heap_census( void )
{
  return TICK_TO_DBL(HC_start_time - GC_tot_time - RP_tot_time - HC_tot_time);
}
#endif /* PROFILING */

void
initStats(void)
{
    nat i;
  
    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_times = 
	(Ticks *)stgMallocBytes(
	    sizeof(Ticks)*RtsFlags.GcFlags.generations,
	    "initStats");
    GC_coll_etimes = 
	(Ticks *)stgMallocBytes(
	    sizeof(Ticks)*RtsFlags.GcFlags.generations,
	    "initStats");
    for (i = 0; i < RtsFlags.GcFlags.generations; i++) {
	GC_coll_times[i] = 0;
	GC_coll_etimes[i] = 0;
    }
}    

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

void
stat_startInit(void)
{
    Ticks elapsed;

    elapsed = getProcessElapsedTime();
    ElapsedTimeStart = elapsed;
}

void 
stat_endInit(void)
{
    Ticks user, elapsed;

    getProcessTimes(&user, &elapsed);

    InitUserTime = user;
    InitElapsedStamp = elapsed; 
    if (ElapsedTimeStart > elapsed) {
	InitElapsedTime = 0;
    } else {
	InitElapsedTime = elapsed - ElapsedTimeStart;
    }
#if USE_PAPI
    /* We start counting events for the mutator
     * when garbage collection starts
     * we switch to the GC event set. */
    papi_start_mutator_count();

    /* This flag is needed to avoid counting the last GC */
    papi_is_reporting = 1;

#endif
}

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

void
stat_startExit(void)
{
    Ticks user, elapsed;

    getProcessTimes(&user, &elapsed);

    MutElapsedStamp = elapsed;
    MutElapsedTime = elapsed - GCe_tot_time -
	PROF_VAL(RPe_tot_time + HCe_tot_time) - InitElapsedStamp;
    if (MutElapsedTime < 0) { MutElapsedTime = 0; }	/* sometimes -0.00 */

    MutUserTime = user - GC_tot_time - PROF_VAL(RP_tot_time + HC_tot_time) - InitUserTime;
    if (MutUserTime < 0) { MutUserTime = 0; }

#if USE_PAPI
    /* We stop counting mutator events
     * GC events are not being counted at this point */
    papi_stop_mutator_count();

    /* This flag is needed, because GC is run once more after this function */
    papi_is_reporting = 0;

#endif
}

void
stat_endExit(void)
{
    Ticks user, elapsed;

    getProcessTimes(&user, &elapsed);

    ExitUserTime = user - MutUserTime - GC_tot_time - PROF_VAL(RP_tot_time + HC_tot_time) - InitUserTime;
    ExitElapsedTime = elapsed - MutElapsedStamp;
    if (ExitUserTime < 0) {
	ExitUserTime = 0;
    }
    if (ExitElapsedTime < 0) {
	ExitElapsedTime = 0;
    }
}

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

static nat rub_bell = 0;

/*  initialise global variables needed during GC
 *
 *  * GC_start_time is read in mut_user_time_during_GC(), which in turn is 
 *    needed if either PROFILING or DEBUGing is enabled
 */
void
stat_startGC(void)
{
    nat bell = RtsFlags.GcFlags.ringBell;

    if (bell) {
	if (bell > 1) {
	    debugBelch(" GC ");
	    rub_bell = 1;
	} else {
	    debugBelch("\007");
	}
    }

#if defined(PROFILING) || defined(DEBUG)
    GC_start_time = getProcessCPUTime();  // needed in mut_user_time_during_GC()
#endif

    if (RtsFlags.GcFlags.giveStats != NO_GC_STATS) {
#if !defined(PROFILING) && !defined(DEBUG)
        GC_start_time = getProcessCPUTime();
#endif
	GCe_start_time = getProcessElapsedTime();
	if (RtsFlags.GcFlags.giveStats) {
	    GC_start_faults = getPageFaults();
	}
    }

#if USE_PAPI
    if(papi_is_reporting) {
      /* Switch to counting GC events */
      papi_stop_mutator_count();
      papi_start_gc_count();
    }
#endif

}

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

void
stat_endGC (lnat alloc, lnat live, lnat copied, lnat gen)
{
    if (RtsFlags.GcFlags.giveStats != NO_GC_STATS) {
	Ticks time, etime, gc_time, gc_etime;
	
	getProcessTimes(&time, &etime);
	gc_time  = time - GC_start_time;
	gc_etime = etime - GCe_start_time;
	
	if (RtsFlags.GcFlags.giveStats == VERBOSE_GC_STATS) {
	    nat faults = getPageFaults();
	    
	    statsPrintf("%9ld %9ld %9ld",
		    alloc*sizeof(W_), copied*sizeof(W_), 
			live*sizeof(W_));
	    statsPrintf(" %5.2f %5.2f %7.2f %7.2f %4ld %4ld  (Gen: %2ld)\n", 
		    TICK_TO_DBL(gc_time),
		    TICK_TO_DBL(gc_etime),
		    TICK_TO_DBL(time),
		    TICK_TO_DBL(etime - ElapsedTimeStart),
		    faults - GC_start_faults,
		    GC_start_faults - GC_end_faults,
		    gen);

	    GC_end_faults = faults;
	    statsFlush();
	}

	GC_coll_times[gen] += gc_time;
	GC_coll_etimes[gen] += gc_etime;

	GC_tot_copied += (ullong) copied;
	GC_tot_alloc  += (ullong) alloc;
	GC_tot_time   += gc_time;
	GCe_tot_time  += gc_etime;
	
#if defined(THREADED_RTS)
	{
	    Task *task;
	    if ((task = myTask()) != NULL) {
		task->gc_time += gc_time;
		task->gc_etime += gc_etime;
	    }
	}
#endif

	if (gen == RtsFlags.GcFlags.generations-1) { /* major GC? */
	    if (live > MaxResidency) {
		MaxResidency = live;
	    }
	    ResidencySamples++;
	    AvgResidency += live;
	}
    }

    if (rub_bell) {
	debugBelch("\b\b\b  \b\b\b");
	rub_bell = 0;
    }

#if USE_PAPI
    if(papi_is_reporting) {
      /* Switch to counting mutator events */
      if (gen == 0) {
          papi_stop_gc0_count();
      } else {
          papi_stop_gc1_count();
      }
      papi_start_mutator_count();
    }
#endif
}

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

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

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

#ifdef PROFILING
void
stat_endRP(
  nat retainerGeneration,
#ifdef DEBUG_RETAINER
  nat maxCStackSize,
  int maxStackSize,
#endif
  double averageNumVisit)
{
    Ticks 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());
#ifdef DEBUG_RETAINER
  fprintf(prof_file, "\tMax C stack size = %u\n", maxCStackSize);
  fprintf(prof_file, "\tMax auxiliary stack size = %u\n", maxStackSize);
#endif
  fprintf(prof_file, "\tAverage number of visits per object = %f\n", averageNumVisit);
}
#endif /* PROFILING */

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

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

/* -----------------------------------------------------------------------------
   Called at the end of each heap census
   -------------------------------------------------------------------------- */
#ifdef PROFILING
void
stat_endHeapCensus(void) 
{
    Ticks 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.
   -------------------------------------------------------------------------- */

#ifdef DEBUG
#define TICK_VAR(arity) \
  extern StgInt SLOW_CALLS_##arity; \
  extern StgInt RIGHT_ARITY_##arity; \
  extern StgInt TAGGED_PTR_##arity;

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

extern StgInt TOTAL_CALLS;

TICK_VAR(1)
TICK_VAR(2)

TICK_VAR_INI(1)
TICK_VAR_INI(2)

StgInt TOTAL_CALLS=1;
#endif

/* Report the value of a counter */
#define REPORT(counter) \
  { \
    ullong_format_string(counter,temp,rtsTrue/*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)


void
stat_exit(int alloc)
{
    if (RtsFlags.GcFlags.giveStats != NO_GC_STATS) {

	char temp[BIG_STRING_LEN];
	Ticks time;
	Ticks etime;
	nat g, total_collections = 0;

	getProcessTimes( &time, &etime );
	etime -= ElapsedTimeStart;

	GC_tot_alloc += alloc;

	/* Count total garbage collections */
	for (g = 0; g < RtsFlags.GcFlags.generations; g++)
	    total_collections += generations[g].collections;

	/* avoid divide by zero if time is measured as 0.00 seconds -- SDM */
	if (time  == 0.0)  time = 1;
	if (etime == 0.0) etime = 1;
	
	if (RtsFlags.GcFlags.giveStats >= VERBOSE_GC_STATS) {
	    statsPrintf("%9ld %9.9s %9.9s", (lnat)alloc*sizeof(W_), "", "");
	    statsPrintf(" %5.2f %5.2f\n\n", 0.0, 0.0);
	}

	if (RtsFlags.GcFlags.giveStats >= SUMMARY_GC_STATS) {
	    ullong_format_string(GC_tot_alloc*sizeof(W_), 
				 temp, rtsTrue/*commas*/);
	    statsPrintf("%11s bytes allocated in the heap\n", temp);

	    ullong_format_string(GC_tot_copied*sizeof(W_), 
				 temp, rtsTrue/*commas*/);
	    statsPrintf("%11s bytes copied during GC\n", temp);

	    if ( ResidencySamples > 0 ) {
		ullong_format_string(MaxResidency*sizeof(W_), 
				     temp, rtsTrue/*commas*/);
		statsPrintf("%11s bytes maximum residency (%ld sample(s))\n",
			temp, ResidencySamples);
	    }
	    statsPrintf("\n");

	    /* Print garbage collections in each gen */
	    for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
		statsPrintf("%11d collections in generation %d, %6.2fs, %6.2fs elapsed\n", 
			generations[g].collections, g, 
                        TICK_TO_DBL(GC_coll_times[g]),
                        TICK_TO_DBL(GC_coll_etimes[g]));
	    }

	    statsPrintf("\n%11ld MB total memory in use\n\n", 
		    mblocks_allocated * MBLOCK_SIZE / (1024 * 1024));

#if defined(THREADED_RTS)
	    {
		nat i;
		Task *task;
		for (i = 0, task = all_tasks; 
		     task != NULL; 
		     i++, task = task->all_link) {
		    statsPrintf("  Task %2d %-8s :  MUT time: %6.2fs  (%6.2fs elapsed)\n"
			    "                      GC  time: %6.2fs  (%6.2fs elapsed)\n\n", 
				i,
				(task->tso == NULL) ? "(worker)" : "(bound)",
				TICK_TO_DBL(task->mut_time),
				TICK_TO_DBL(task->mut_etime),
				TICK_TO_DBL(task->gc_time),
				TICK_TO_DBL(task->gc_etime));
		}
	    }
#endif

	    statsPrintf("  INIT  time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(InitUserTime), TICK_TO_DBL(InitElapsedTime));
	    statsPrintf("  MUT   time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(MutUserTime), TICK_TO_DBL(MutElapsedTime));
	    statsPrintf("  GC    time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(GC_tot_time), TICK_TO_DBL(GCe_tot_time));
#ifdef PROFILING
	    statsPrintf("  RP    time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(RP_tot_time), TICK_TO_DBL(RPe_tot_time));
	    statsPrintf("  PROF  time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(HC_tot_time), TICK_TO_DBL(HCe_tot_time));
#endif 
	    statsPrintf("  EXIT  time  %6.2fs  (%6.2fs elapsed)\n",
		    TICK_TO_DBL(ExitUserTime), TICK_TO_DBL(ExitElapsedTime));
	    statsPrintf("  Total time  %6.2fs  (%6.2fs elapsed)\n\n",
		    TICK_TO_DBL(time), TICK_TO_DBL(etime));
	    statsPrintf("  %%GC time     %5.1f%%  (%.1f%% elapsed)\n\n",
		    TICK_TO_DBL(GC_tot_time)*100/TICK_TO_DBL(time),
		    TICK_TO_DBL(GCe_tot_time)*100/TICK_TO_DBL(etime));

	    if (time - GC_tot_time - PROF_VAL(RP_tot_time + HC_tot_time) == 0)
		ullong_format_string(0, temp, rtsTrue/*commas*/);
	    else
		ullong_format_string(
		    (ullong)((GC_tot_alloc*sizeof(W_))/
			     TICK_TO_DBL(time - GC_tot_time - 
					 PROF_VAL(RP_tot_time + HC_tot_time))),
		    temp, rtsTrue/*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",
		    TICK_TO_DBL(time - GC_tot_time - 
				PROF_VAL(RP_tot_time + HC_tot_time) - InitUserTime) * 100 
		    / TICK_TO_DBL(time), 
		    TICK_TO_DBL(time - GC_tot_time - 
				PROF_VAL(RP_tot_time + HC_tot_time) - InitUserTime) * 100 
		    / TICK_TO_DBL(etime));

            /*
            TICK_PRINT(1);
            TICK_PRINT(2);
	    REPORT(TOTAL_CALLS);
            TICK_PRINT_TOT(1);
            TICK_PRINT_TOT(2);
            */

#if USE_PAPI
            papi_stats_report();
#endif
	}

	if (RtsFlags.GcFlags.giveStats == ONELINE_GC_STATS) {
	  /* print the long long separately to avoid bugginess on mingwin (2001-07-02, mingw-0.5) */
	  statsPrintf("<<ghc: %llu bytes, ", GC_tot_alloc*(ullong)sizeof(W_));
	  statsPrintf("%d GCs, %ld/%ld avg/max bytes residency (%ld samples), %luM in use, %.2f INIT (%.2f elapsed), %.2f MUT (%.2f elapsed), %.2f GC (%.2f elapsed) :ghc>>\n",
		    total_collections,
		    ResidencySamples == 0 ? 0 : 
		        AvgResidency*sizeof(W_)/ResidencySamples, 
		    MaxResidency*sizeof(W_), 
		    ResidencySamples,
		    (unsigned long)(mblocks_allocated * MBLOCK_SIZE / (1024L * 1024L)),
		    TICK_TO_DBL(InitUserTime), TICK_TO_DBL(InitElapsedTime),
		    TICK_TO_DBL(MutUserTime), TICK_TO_DBL(MutElapsedTime),
		    TICK_TO_DBL(GC_tot_time), TICK_TO_DBL(GCe_tot_time));
	}

	statsFlush();
	statsClose();
    }
    if (GC_coll_times)
      stgFree(GC_coll_times);
    GC_coll_times = NULL;
}

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

   Produce some detailed info on the state of the generational GC.
   -------------------------------------------------------------------------- */
#ifdef DEBUG
void
statDescribeGens(void)
{
  nat g, s, mut, lge;
  lnat live;
  bdescr *bd;
  step *step;

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

  mut = 0;
  for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
      for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
	  mut += (bd->free - bd->start) * sizeof(W_);
      }

    debugBelch("%8d %8d %8d %9d", g, generations[g].n_steps,
	    generations[g].max_blocks, mut);

    for (s = 0; s < generations[g].n_steps; s++) {
      step = &generations[g].steps[s];
      live = 0;
      for (bd = step->large_objects, lge = 0; bd; bd = bd->link) {
	lge++;
      }
      // This live figure will be slightly less that the "live" figure
      // given by +RTS -Sstderr, because we take don't count the
      // slop at the end of each block.
      live += countOccupied(step->blocks) + countOccupied(step->large_objects);
      if (s != 0) {
	debugBelch("%36s","");
      }
      debugBelch("%6d %8d %8ld %8d\n", s, step->n_blocks,
	      live, lge);
    }
  }
  debugBelch("\n");
}
#endif

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

extern HsInt64 getAllocations( void ) 
{ return (HsInt64)total_allocated * sizeof(W_); }

/* -----------------------------------------------------------------------------
   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);
    }
}