1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
5 * Storage manager front end
7 * ---------------------------------------------------------------------------*/
9 #include "PosixSource.h"
15 #include "BlockAlloc.h"
20 #include "OSThreads.h"
21 #include "Capability.h"
24 #include "RetainerProfile.h" // for counting memory blocks (memInventory)
29 StgClosure *caf_list = NULL;
30 StgClosure *revertible_caf_list = NULL;
33 bdescr *small_alloc_list; /* allocate()d small objects */
34 bdescr *pinned_object_block; /* allocate pinned objects into this block */
35 nat alloc_blocks; /* number of allocate()d blocks since GC */
36 nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
38 StgPtr alloc_Hp = NULL; /* next free byte in small_alloc_list */
39 StgPtr alloc_HpLim = NULL; /* end of block at small_alloc_list */
41 generation *generations = NULL; /* all the generations */
42 generation *g0 = NULL; /* generation 0, for convenience */
43 generation *oldest_gen = NULL; /* oldest generation, for convenience */
44 step *g0s0 = NULL; /* generation 0, step 0, for convenience */
46 ullong total_allocated = 0; /* total memory allocated during run */
49 * Storage manager mutex: protects all the above state from
50 * simultaneous access by two STG threads.
53 Mutex sm_mutex = INIT_MUTEX_VAR;
59 static void *stgAllocForGMP (size_t size_in_bytes);
60 static void *stgReallocForGMP (void *ptr, size_t old_size, size_t new_size);
61 static void stgDeallocForGMP (void *ptr, size_t size);
64 * Storage manager mutex
67 extern Mutex sm_mutex;
68 #define ACQUIRE_SM_LOCK ACQUIRE_LOCK(&sm_mutex)
69 #define RELEASE_SM_LOCK RELEASE_LOCK(&sm_mutex)
71 #define ACQUIRE_SM_LOCK
72 #define RELEASE_SM_LOCK
82 if (generations != NULL) {
83 // multi-init protection
87 /* Sanity check to make sure the LOOKS_LIKE_ macros appear to be
88 * doing something reasonable.
90 ASSERT(LOOKS_LIKE_INFO_PTR(&stg_BLACKHOLE_info));
91 ASSERT(LOOKS_LIKE_CLOSURE_PTR(&stg_dummy_ret_closure));
92 ASSERT(!HEAP_ALLOCED(&stg_dummy_ret_closure));
94 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
95 RtsFlags.GcFlags.heapSizeSuggestion >
96 RtsFlags.GcFlags.maxHeapSize) {
97 RtsFlags.GcFlags.maxHeapSize = RtsFlags.GcFlags.heapSizeSuggestion;
100 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
101 RtsFlags.GcFlags.minAllocAreaSize >
102 RtsFlags.GcFlags.maxHeapSize) {
103 errorBelch("maximum heap size (-M) is smaller than minimum alloc area size (-A)");
107 initBlockAllocator();
110 initMutex(&sm_mutex);
113 /* allocate generation info array */
114 generations = (generation *)stgMallocBytes(RtsFlags.GcFlags.generations
115 * sizeof(struct _generation),
116 "initStorage: gens");
118 /* Initialise all generations */
119 for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
120 gen = &generations[g];
122 gen->mut_list = allocBlock();
123 gen->collections = 0;
124 gen->failed_promotions = 0;
128 /* A couple of convenience pointers */
129 g0 = &generations[0];
130 oldest_gen = &generations[RtsFlags.GcFlags.generations-1];
132 /* Allocate step structures in each generation */
133 if (RtsFlags.GcFlags.generations > 1) {
134 /* Only for multiple-generations */
136 /* Oldest generation: one step */
137 oldest_gen->n_steps = 1;
139 stgMallocBytes(1 * sizeof(struct _step), "initStorage: last step");
141 /* set up all except the oldest generation with 2 steps */
142 for(g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
143 generations[g].n_steps = RtsFlags.GcFlags.steps;
144 generations[g].steps =
145 stgMallocBytes (RtsFlags.GcFlags.steps * sizeof(struct _step),
146 "initStorage: steps");
150 /* single generation, i.e. a two-space collector */
152 g0->steps = stgMallocBytes (sizeof(struct _step), "initStorage: steps");
155 /* Initialise all steps */
156 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
157 for (s = 0; s < generations[g].n_steps; s++) {
158 stp = &generations[g].steps[s];
161 stp->n_to_blocks = 0;
163 stp->gen = &generations[g];
170 stp->large_objects = NULL;
171 stp->n_large_blocks = 0;
172 stp->new_large_objects = NULL;
173 stp->scavenged_large_objects = NULL;
174 stp->n_scavenged_large_blocks = 0;
175 stp->is_compacted = 0;
180 /* Set up the destination pointers in each younger gen. step */
181 for (g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
182 for (s = 0; s < generations[g].n_steps-1; s++) {
183 generations[g].steps[s].to = &generations[g].steps[s+1];
185 generations[g].steps[s].to = &generations[g+1].steps[0];
188 /* The oldest generation has one step and it is compacted. */
189 if (RtsFlags.GcFlags.compact) {
190 if (RtsFlags.GcFlags.generations == 1) {
191 errorBelch("WARNING: compaction is incompatible with -G1; disabled");
193 oldest_gen->steps[0].is_compacted = 1;
196 oldest_gen->steps[0].to = &oldest_gen->steps[0];
198 /* generation 0 is special: that's the nursery */
199 generations[0].max_blocks = 0;
201 /* G0S0: the allocation area. Policy: keep the allocation area
202 * small to begin with, even if we have a large suggested heap
203 * size. Reason: we're going to do a major collection first, and we
204 * don't want it to be a big one. This vague idea is borne out by
205 * rigorous experimental evidence.
207 g0s0 = &generations[0].steps[0];
211 weak_ptr_list = NULL;
213 revertible_caf_list = NULL;
215 /* initialise the allocate() interface */
216 small_alloc_list = NULL;
218 alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
220 /* Tell GNU multi-precision pkg about our custom alloc functions */
221 mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
223 IF_DEBUG(gc, statDescribeGens());
229 stat_exit(calcAllocated());
232 /* -----------------------------------------------------------------------------
235 The entry code for every CAF does the following:
237 - builds a CAF_BLACKHOLE in the heap
238 - pushes an update frame pointing to the CAF_BLACKHOLE
239 - invokes UPD_CAF(), which:
240 - calls newCaf, below
241 - updates the CAF with a static indirection to the CAF_BLACKHOLE
243 Why do we build a BLACKHOLE in the heap rather than just updating
244 the thunk directly? It's so that we only need one kind of update
245 frame - otherwise we'd need a static version of the update frame too.
247 newCaf() does the following:
249 - it puts the CAF on the oldest generation's mut-once list.
250 This is so that we can treat the CAF as a root when collecting
253 For GHCI, we have additional requirements when dealing with CAFs:
255 - we must *retain* all dynamically-loaded CAFs ever entered,
256 just in case we need them again.
257 - we must be able to *revert* CAFs that have been evaluated, to
258 their pre-evaluated form.
260 To do this, we use an additional CAF list. When newCaf() is
261 called on a dynamically-loaded CAF, we add it to the CAF list
262 instead of the old-generation mutable list, and save away its
263 old info pointer (in caf->saved_info) for later reversion.
265 To revert all the CAFs, we traverse the CAF list and reset the
266 info pointer to caf->saved_info, then throw away the CAF list.
267 (see GC.c:revertCAFs()).
271 -------------------------------------------------------------------------- */
274 newCAF(StgClosure* caf)
281 // If we are in GHCi _and_ we are using dynamic libraries,
282 // then we can't redirect newCAF calls to newDynCAF (see below),
283 // so we make newCAF behave almost like newDynCAF.
284 // The dynamic libraries might be used by both the interpreted
285 // program and GHCi itself, so they must not be reverted.
286 // This also means that in GHCi with dynamic libraries, CAFs are not
287 // garbage collected. If this turns out to be a problem, we could
288 // do another hack here and do an address range test on caf to figure
289 // out whether it is from a dynamic library.
290 ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
291 ((StgIndStatic *)caf)->static_link = caf_list;
296 /* Put this CAF on the mutable list for the old generation.
297 * This is a HACK - the IND_STATIC closure doesn't really have
298 * a mut_link field, but we pretend it has - in fact we re-use
299 * the STATIC_LINK field for the time being, because when we
300 * come to do a major GC we won't need the mut_link field
301 * any more and can use it as a STATIC_LINK.
303 ((StgIndStatic *)caf)->saved_info = NULL;
304 recordMutableGen(caf, oldest_gen);
310 /* If we are PAR or DIST then we never forget a CAF */
312 //debugBelch("<##> Globalising CAF %08x %s",caf,info_type(caf));
313 newGA=makeGlobal(caf,rtsTrue); /*given full weight*/
319 // An alternate version of newCaf which is used for dynamically loaded
320 // object code in GHCi. In this case we want to retain *all* CAFs in
321 // the object code, because they might be demanded at any time from an
322 // expression evaluated on the command line.
323 // Also, GHCi might want to revert CAFs, so we add these to the
324 // revertible_caf_list.
326 // The linker hackily arranges that references to newCaf from dynamic
327 // code end up pointing to newDynCAF.
329 newDynCAF(StgClosure *caf)
333 ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
334 ((StgIndStatic *)caf)->static_link = revertible_caf_list;
335 revertible_caf_list = caf;
340 /* -----------------------------------------------------------------------------
342 -------------------------------------------------------------------------- */
345 allocNurseries( void )
352 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
353 cap->r.rNursery = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
354 cap->r.rCurrentNursery = cap->r.rNursery;
357 g0s0->blocks = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
358 g0s0->n_blocks = RtsFlags.GcFlags.minAllocAreaSize;
359 g0s0->to_blocks = NULL;
360 g0s0->n_to_blocks = 0;
361 MainCapability.r.rNursery = g0s0->blocks;
362 MainCapability.r.rCurrentNursery = g0s0->blocks;
363 /* hp, hpLim, hp_bd, to_space etc. aren't used in G0S0 */
368 resetNurseries( void )
374 /* All tasks must be stopped */
375 ASSERT(rts_n_free_capabilities == RtsFlags.ParFlags.nNodes);
376 for (cap = free_capabilities; cap != NULL; cap = cap->link)
378 cap = &MainCapability;
379 ASSERT(cap->r.rNursery == g0s0->blocks);
382 for (bd = cap->r.rNursery; bd; bd = bd->link) {
383 bd->free = bd->start;
384 ASSERT(bd->gen_no == 0);
385 ASSERT(bd->step == g0s0);
386 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
388 cap->r.rCurrentNursery = cap->r.rNursery;
393 allocNursery (bdescr *tail, nat blocks)
398 // Allocate a nursery: we allocate fresh blocks one at a time and
399 // cons them on to the front of the list, not forgetting to update
400 // the back pointer on the tail of the list to point to the new block.
401 for (i=0; i < blocks; i++) {
404 processNursery() in LdvProfile.c assumes that every block group in
405 the nursery contains only a single block. So, if a block group is
406 given multiple blocks, change processNursery() accordingly.
410 // double-link the nursery: we might need to insert blocks
417 bd->free = bd->start;
425 resizeNursery ( nat blocks )
431 barf("resizeNursery: can't resize in SMP mode");
434 nursery_blocks = g0s0->n_blocks;
435 if (nursery_blocks == blocks) {
439 else if (nursery_blocks < blocks) {
440 IF_DEBUG(gc, debugBelch("Increasing size of nursery to %d blocks\n",
442 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
448 IF_DEBUG(gc, debugBelch("Decreasing size of nursery to %d blocks\n",
452 while (nursery_blocks > blocks) {
454 next_bd->u.back = NULL;
455 nursery_blocks -= bd->blocks; // might be a large block
460 // might have gone just under, by freeing a large block, so make
461 // up the difference.
462 if (nursery_blocks < blocks) {
463 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
467 g0s0->n_blocks = blocks;
468 ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
470 MainCapability.r.rNursery = g0s0->blocks;
473 /* -----------------------------------------------------------------------------
474 The allocate() interface
476 allocate(n) always succeeds, and returns a chunk of memory n words
477 long. n can be larger than the size of a block if necessary, in
478 which case a contiguous block group will be allocated.
479 -------------------------------------------------------------------------- */
489 TICK_ALLOC_HEAP_NOCTR(n);
492 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
493 /* ToDo: allocate directly into generation 1 */
494 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
495 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
496 bd = allocGroup(req_blocks);
497 dbl_link_onto(bd, &g0s0->large_objects);
498 g0s0->n_large_blocks += req_blocks;
501 bd->flags = BF_LARGE;
502 bd->free = bd->start + n;
503 alloc_blocks += req_blocks;
507 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
508 } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
509 if (small_alloc_list) {
510 small_alloc_list->free = alloc_Hp;
513 bd->link = small_alloc_list;
514 small_alloc_list = bd;
518 alloc_Hp = bd->start;
519 alloc_HpLim = bd->start + BLOCK_SIZE_W;
530 allocated_bytes( void )
534 allocated = alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp);
535 if (pinned_object_block != NULL) {
536 allocated -= (pinned_object_block->start + BLOCK_SIZE_W) -
537 pinned_object_block->free;
544 tidyAllocateLists (void)
546 if (small_alloc_list != NULL) {
547 ASSERT(alloc_Hp >= small_alloc_list->start &&
548 alloc_Hp <= small_alloc_list->start + BLOCK_SIZE);
549 small_alloc_list->free = alloc_Hp;
553 /* ---------------------------------------------------------------------------
554 Allocate a fixed/pinned object.
556 We allocate small pinned objects into a single block, allocating a
557 new block when the current one overflows. The block is chained
558 onto the large_object_list of generation 0 step 0.
560 NOTE: The GC can't in general handle pinned objects. This
561 interface is only safe to use for ByteArrays, which have no
562 pointers and don't require scavenging. It works because the
563 block's descriptor has the BF_LARGE flag set, so the block is
564 treated as a large object and chained onto various lists, rather
565 than the individual objects being copied. However, when it comes
566 to scavenge the block, the GC will only scavenge the first object.
567 The reason is that the GC can't linearly scan a block of pinned
568 objects at the moment (doing so would require using the
569 mostly-copying techniques). But since we're restricting ourselves
570 to pinned ByteArrays, not scavenging is ok.
572 This function is called by newPinnedByteArray# which immediately
573 fills the allocated memory with a MutableByteArray#.
574 ------------------------------------------------------------------------- */
577 allocatePinned( nat n )
580 bdescr *bd = pinned_object_block;
582 // If the request is for a large object, then allocate()
583 // will give us a pinned object anyway.
584 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
590 TICK_ALLOC_HEAP_NOCTR(n);
593 // we always return 8-byte aligned memory. bd->free must be
594 // 8-byte aligned to begin with, so we just round up n to
595 // the nearest multiple of 8 bytes.
596 if (sizeof(StgWord) == 4) {
600 // If we don't have a block of pinned objects yet, or the current
601 // one isn't large enough to hold the new object, allocate a new one.
602 if (bd == NULL || (bd->free + n) > (bd->start + BLOCK_SIZE_W)) {
603 pinned_object_block = bd = allocBlock();
604 dbl_link_onto(bd, &g0s0->large_objects);
607 bd->flags = BF_PINNED | BF_LARGE;
608 bd->free = bd->start;
618 /* -----------------------------------------------------------------------------
619 Allocation functions for GMP.
621 These all use the allocate() interface - we can't have any garbage
622 collection going on during a gmp operation, so we use allocate()
623 which always succeeds. The gmp operations which might need to
624 allocate will ask the storage manager (via doYouWantToGC()) whether
625 a garbage collection is required, in case we get into a loop doing
626 only allocate() style allocation.
627 -------------------------------------------------------------------------- */
630 stgAllocForGMP (size_t size_in_bytes)
633 nat data_size_in_words, total_size_in_words;
635 /* round up to a whole number of words */
636 data_size_in_words = (size_in_bytes + sizeof(W_) + 1) / sizeof(W_);
637 total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
639 /* allocate and fill it in. */
640 arr = (StgArrWords *)allocate(total_size_in_words);
641 SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
643 /* and return a ptr to the goods inside the array */
648 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
650 void *new_stuff_ptr = stgAllocForGMP(new_size);
652 char *p = (char *) ptr;
653 char *q = (char *) new_stuff_ptr;
655 for (; i < old_size; i++, p++, q++) {
659 return(new_stuff_ptr);
663 stgDeallocForGMP (void *ptr STG_UNUSED,
664 size_t size STG_UNUSED)
666 /* easy for us: the garbage collector does the dealloc'n */
669 /* -----------------------------------------------------------------------------
671 * -------------------------------------------------------------------------- */
673 /* -----------------------------------------------------------------------------
676 * Approximate how much we've allocated: number of blocks in the
677 * nursery + blocks allocated via allocate() - unused nusery blocks.
678 * This leaves a little slop at the end of each block, and doesn't
679 * take into account large objects (ToDo).
680 * -------------------------------------------------------------------------- */
683 calcAllocated( void )
691 /* All tasks must be stopped. Can't assert that all the
692 capabilities are owned by the scheduler, though: one or more
693 tasks might have been stopped while they were running (non-main)
695 /* ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes); */
698 rts_n_free_capabilities * RtsFlags.GcFlags.minAllocAreaSize * BLOCK_SIZE_W
701 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
702 for ( bd = cap->r.rCurrentNursery->link; bd != NULL; bd = bd->link ) {
703 allocated -= BLOCK_SIZE_W;
705 if (cap->r.rCurrentNursery->free < cap->r.rCurrentNursery->start
707 allocated -= (cap->r.rCurrentNursery->start + BLOCK_SIZE_W)
708 - cap->r.rCurrentNursery->free;
713 bdescr *current_nursery = MainCapability.r.rCurrentNursery;
715 allocated = (g0s0->n_blocks * BLOCK_SIZE_W) + allocated_bytes();
716 for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
717 allocated -= BLOCK_SIZE_W;
719 if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
720 allocated -= (current_nursery->start + BLOCK_SIZE_W)
721 - current_nursery->free;
725 total_allocated += allocated;
729 /* Approximate the amount of live data in the heap. To be called just
730 * after garbage collection (see GarbageCollect()).
739 if (RtsFlags.GcFlags.generations == 1) {
740 live = (g0s0->n_to_blocks - 1) * BLOCK_SIZE_W +
741 ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
745 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
746 for (s = 0; s < generations[g].n_steps; s++) {
747 /* approximate amount of live data (doesn't take into account slop
748 * at end of each block).
750 if (g == 0 && s == 0) {
753 stp = &generations[g].steps[s];
754 live += (stp->n_large_blocks + stp->n_blocks - 1) * BLOCK_SIZE_W;
755 if (stp->hp_bd != NULL) {
756 live += ((lnat)stp->hp_bd->free - (lnat)stp->hp_bd->start)
764 /* Approximate the number of blocks that will be needed at the next
765 * garbage collection.
767 * Assume: all data currently live will remain live. Steps that will
768 * be collected next time will therefore need twice as many blocks
769 * since all the data will be copied.
778 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
779 for (s = 0; s < generations[g].n_steps; s++) {
780 if (g == 0 && s == 0) { continue; }
781 stp = &generations[g].steps[s];
782 if (generations[g].steps[0].n_blocks +
783 generations[g].steps[0].n_large_blocks
784 > generations[g].max_blocks
785 && stp->is_compacted == 0) {
786 needed += 2 * stp->n_blocks;
788 needed += stp->n_blocks;
795 /* -----------------------------------------------------------------------------
798 memInventory() checks for memory leaks by counting up all the
799 blocks we know about and comparing that to the number of blocks
800 allegedly floating around in the system.
801 -------------------------------------------------------------------------- */
811 lnat total_blocks = 0, free_blocks = 0;
813 /* count the blocks we current have */
815 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
816 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
817 total_blocks += bd->blocks;
819 for (s = 0; s < generations[g].n_steps; s++) {
820 stp = &generations[g].steps[s];
821 total_blocks += stp->n_blocks;
822 if (RtsFlags.GcFlags.generations == 1) {
823 /* two-space collector has a to-space too :-) */
824 total_blocks += g0s0->n_to_blocks;
826 for (bd = stp->large_objects; bd; bd = bd->link) {
827 total_blocks += bd->blocks;
828 /* hack for megablock groups: they have an extra block or two in
829 the second and subsequent megablocks where the block
830 descriptors would normally go.
832 if (bd->blocks > BLOCKS_PER_MBLOCK) {
833 total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
834 * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
840 /* any blocks held by allocate() */
841 for (bd = small_alloc_list; bd; bd = bd->link) {
842 total_blocks += bd->blocks;
846 if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
847 total_blocks += retainerStackBlocks();
851 // count the blocks allocated by the arena allocator
852 total_blocks += arenaBlocks();
854 /* count the blocks on the free list */
855 free_blocks = countFreeList();
857 if (total_blocks + free_blocks != mblocks_allocated *
859 debugBelch("Blocks: %ld live + %ld free = %ld total (%ld around)\n",
860 total_blocks, free_blocks, total_blocks + free_blocks,
861 mblocks_allocated * BLOCKS_PER_MBLOCK);
864 ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
869 countBlocks(bdescr *bd)
872 for (n=0; bd != NULL; bd=bd->link) {
878 /* Full heap sanity check. */
884 if (RtsFlags.GcFlags.generations == 1) {
885 checkHeap(g0s0->to_blocks);
886 checkChain(g0s0->large_objects);
889 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
890 for (s = 0; s < generations[g].n_steps; s++) {
891 ASSERT(countBlocks(generations[g].steps[s].blocks)
892 == generations[g].steps[s].n_blocks);
893 ASSERT(countBlocks(generations[g].steps[s].large_objects)
894 == generations[g].steps[s].n_large_blocks);
895 if (g == 0 && s == 0) { continue; }
896 checkHeap(generations[g].steps[s].blocks);
897 checkChain(generations[g].steps[s].large_objects);
899 checkMutableList(generations[g].mut_list, g);
903 checkFreeListSanity();
907 // handy function for use in gdb, because Bdescr() is inlined.
908 extern bdescr *_bdescr( StgPtr p );