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;
381 for (bd = cap->r.rNursery; bd; bd = bd->link) {
382 bd->free = bd->start;
383 ASSERT(bd->gen_no == 0);
384 ASSERT(bd->step == g0s0);
385 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
387 cap->r.rCurrentNursery = cap->r.rNursery;
392 allocNursery (bdescr *tail, nat blocks)
397 // Allocate a nursery: we allocate fresh blocks one at a time and
398 // cons them on to the front of the list, not forgetting to update
399 // the back pointer on the tail of the list to point to the new block.
400 for (i=0; i < blocks; i++) {
403 processNursery() in LdvProfile.c assumes that every block group in
404 the nursery contains only a single block. So, if a block group is
405 given multiple blocks, change processNursery() accordingly.
409 // double-link the nursery: we might need to insert blocks
416 bd->free = bd->start;
424 resizeNursery ( nat blocks )
430 barf("resizeNursery: can't resize in SMP mode");
433 nursery_blocks = g0s0->n_blocks;
434 if (nursery_blocks == blocks) {
438 else if (nursery_blocks < blocks) {
439 IF_DEBUG(gc, debugBelch("Increasing size of nursery to %d blocks\n",
441 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
447 IF_DEBUG(gc, debugBelch("Decreasing size of nursery to %d blocks\n",
451 while (nursery_blocks > blocks) {
453 next_bd->u.back = NULL;
454 nursery_blocks -= bd->blocks; // might be a large block
459 // might have gone just under, by freeing a large block, so make
460 // up the difference.
461 if (nursery_blocks < blocks) {
462 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
466 g0s0->n_blocks = blocks;
467 ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
470 /* -----------------------------------------------------------------------------
471 The allocate() interface
473 allocate(n) always succeeds, and returns a chunk of memory n words
474 long. n can be larger than the size of a block if necessary, in
475 which case a contiguous block group will be allocated.
476 -------------------------------------------------------------------------- */
486 TICK_ALLOC_HEAP_NOCTR(n);
489 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
490 /* ToDo: allocate directly into generation 1 */
491 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
492 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
493 bd = allocGroup(req_blocks);
494 dbl_link_onto(bd, &g0s0->large_objects);
495 g0s0->n_large_blocks += req_blocks;
498 bd->flags = BF_LARGE;
499 bd->free = bd->start + n;
500 alloc_blocks += req_blocks;
504 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
505 } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
506 if (small_alloc_list) {
507 small_alloc_list->free = alloc_Hp;
510 bd->link = small_alloc_list;
511 small_alloc_list = bd;
515 alloc_Hp = bd->start;
516 alloc_HpLim = bd->start + BLOCK_SIZE_W;
527 allocated_bytes( void )
531 allocated = alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp);
532 if (pinned_object_block != NULL) {
533 allocated -= (pinned_object_block->start + BLOCK_SIZE_W) -
534 pinned_object_block->free;
541 tidyAllocateLists (void)
543 if (small_alloc_list != NULL) {
544 ASSERT(alloc_Hp >= small_alloc_list->start &&
545 alloc_Hp <= small_alloc_list->start + BLOCK_SIZE);
546 small_alloc_list->free = alloc_Hp;
550 /* ---------------------------------------------------------------------------
551 Allocate a fixed/pinned object.
553 We allocate small pinned objects into a single block, allocating a
554 new block when the current one overflows. The block is chained
555 onto the large_object_list of generation 0 step 0.
557 NOTE: The GC can't in general handle pinned objects. This
558 interface is only safe to use for ByteArrays, which have no
559 pointers and don't require scavenging. It works because the
560 block's descriptor has the BF_LARGE flag set, so the block is
561 treated as a large object and chained onto various lists, rather
562 than the individual objects being copied. However, when it comes
563 to scavenge the block, the GC will only scavenge the first object.
564 The reason is that the GC can't linearly scan a block of pinned
565 objects at the moment (doing so would require using the
566 mostly-copying techniques). But since we're restricting ourselves
567 to pinned ByteArrays, not scavenging is ok.
569 This function is called by newPinnedByteArray# which immediately
570 fills the allocated memory with a MutableByteArray#.
571 ------------------------------------------------------------------------- */
574 allocatePinned( nat n )
577 bdescr *bd = pinned_object_block;
579 // If the request is for a large object, then allocate()
580 // will give us a pinned object anyway.
581 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
587 TICK_ALLOC_HEAP_NOCTR(n);
590 // we always return 8-byte aligned memory. bd->free must be
591 // 8-byte aligned to begin with, so we just round up n to
592 // the nearest multiple of 8 bytes.
593 if (sizeof(StgWord) == 4) {
597 // If we don't have a block of pinned objects yet, or the current
598 // one isn't large enough to hold the new object, allocate a new one.
599 if (bd == NULL || (bd->free + n) > (bd->start + BLOCK_SIZE_W)) {
600 pinned_object_block = bd = allocBlock();
601 dbl_link_onto(bd, &g0s0->large_objects);
604 bd->flags = BF_PINNED | BF_LARGE;
605 bd->free = bd->start;
615 /* -----------------------------------------------------------------------------
616 Allocation functions for GMP.
618 These all use the allocate() interface - we can't have any garbage
619 collection going on during a gmp operation, so we use allocate()
620 which always succeeds. The gmp operations which might need to
621 allocate will ask the storage manager (via doYouWantToGC()) whether
622 a garbage collection is required, in case we get into a loop doing
623 only allocate() style allocation.
624 -------------------------------------------------------------------------- */
627 stgAllocForGMP (size_t size_in_bytes)
630 nat data_size_in_words, total_size_in_words;
632 /* round up to a whole number of words */
633 data_size_in_words = (size_in_bytes + sizeof(W_) + 1) / sizeof(W_);
634 total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
636 /* allocate and fill it in. */
637 arr = (StgArrWords *)allocate(total_size_in_words);
638 SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
640 /* and return a ptr to the goods inside the array */
645 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
647 void *new_stuff_ptr = stgAllocForGMP(new_size);
649 char *p = (char *) ptr;
650 char *q = (char *) new_stuff_ptr;
652 for (; i < old_size; i++, p++, q++) {
656 return(new_stuff_ptr);
660 stgDeallocForGMP (void *ptr STG_UNUSED,
661 size_t size STG_UNUSED)
663 /* easy for us: the garbage collector does the dealloc'n */
666 /* -----------------------------------------------------------------------------
668 * -------------------------------------------------------------------------- */
670 /* -----------------------------------------------------------------------------
673 * Approximate how much we've allocated: number of blocks in the
674 * nursery + blocks allocated via allocate() - unused nusery blocks.
675 * This leaves a little slop at the end of each block, and doesn't
676 * take into account large objects (ToDo).
677 * -------------------------------------------------------------------------- */
680 calcAllocated( void )
688 /* All tasks must be stopped. Can't assert that all the
689 capabilities are owned by the scheduler, though: one or more
690 tasks might have been stopped while they were running (non-main)
692 /* ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes); */
695 rts_n_free_capabilities * RtsFlags.GcFlags.minAllocAreaSize * BLOCK_SIZE_W
698 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
699 for ( bd = cap->r.rCurrentNursery->link; bd != NULL; bd = bd->link ) {
700 allocated -= BLOCK_SIZE_W;
702 if (cap->r.rCurrentNursery->free < cap->r.rCurrentNursery->start
704 allocated -= (cap->r.rCurrentNursery->start + BLOCK_SIZE_W)
705 - cap->r.rCurrentNursery->free;
710 bdescr *current_nursery = MainCapability.r.rCurrentNursery;
712 allocated = (g0s0->n_blocks * BLOCK_SIZE_W) + allocated_bytes();
713 for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
714 allocated -= BLOCK_SIZE_W;
716 if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
717 allocated -= (current_nursery->start + BLOCK_SIZE_W)
718 - current_nursery->free;
722 total_allocated += allocated;
726 /* Approximate the amount of live data in the heap. To be called just
727 * after garbage collection (see GarbageCollect()).
736 if (RtsFlags.GcFlags.generations == 1) {
737 live = (g0s0->n_to_blocks - 1) * BLOCK_SIZE_W +
738 ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
742 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
743 for (s = 0; s < generations[g].n_steps; s++) {
744 /* approximate amount of live data (doesn't take into account slop
745 * at end of each block).
747 if (g == 0 && s == 0) {
750 stp = &generations[g].steps[s];
751 live += (stp->n_large_blocks + stp->n_blocks - 1) * BLOCK_SIZE_W;
752 if (stp->hp_bd != NULL) {
753 live += ((lnat)stp->hp_bd->free - (lnat)stp->hp_bd->start)
761 /* Approximate the number of blocks that will be needed at the next
762 * garbage collection.
764 * Assume: all data currently live will remain live. Steps that will
765 * be collected next time will therefore need twice as many blocks
766 * since all the data will be copied.
775 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
776 for (s = 0; s < generations[g].n_steps; s++) {
777 if (g == 0 && s == 0) { continue; }
778 stp = &generations[g].steps[s];
779 if (generations[g].steps[0].n_blocks +
780 generations[g].steps[0].n_large_blocks
781 > generations[g].max_blocks
782 && stp->is_compacted == 0) {
783 needed += 2 * stp->n_blocks;
785 needed += stp->n_blocks;
792 /* -----------------------------------------------------------------------------
795 memInventory() checks for memory leaks by counting up all the
796 blocks we know about and comparing that to the number of blocks
797 allegedly floating around in the system.
798 -------------------------------------------------------------------------- */
808 lnat total_blocks = 0, free_blocks = 0;
810 /* count the blocks we current have */
812 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
813 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
814 total_blocks += bd->blocks;
816 for (s = 0; s < generations[g].n_steps; s++) {
817 stp = &generations[g].steps[s];
818 total_blocks += stp->n_blocks;
819 if (RtsFlags.GcFlags.generations == 1) {
820 /* two-space collector has a to-space too :-) */
821 total_blocks += g0s0->n_to_blocks;
823 for (bd = stp->large_objects; bd; bd = bd->link) {
824 total_blocks += bd->blocks;
825 /* hack for megablock groups: they have an extra block or two in
826 the second and subsequent megablocks where the block
827 descriptors would normally go.
829 if (bd->blocks > BLOCKS_PER_MBLOCK) {
830 total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
831 * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
837 /* any blocks held by allocate() */
838 for (bd = small_alloc_list; bd; bd = bd->link) {
839 total_blocks += bd->blocks;
843 if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
844 total_blocks += retainerStackBlocks();
848 // count the blocks allocated by the arena allocator
849 total_blocks += arenaBlocks();
851 /* count the blocks on the free list */
852 free_blocks = countFreeList();
854 if (total_blocks + free_blocks != mblocks_allocated *
856 debugBelch("Blocks: %ld live + %ld free = %ld total (%ld around)\n",
857 total_blocks, free_blocks, total_blocks + free_blocks,
858 mblocks_allocated * BLOCKS_PER_MBLOCK);
861 ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
866 countBlocks(bdescr *bd)
869 for (n=0; bd != NULL; bd=bd->link) {
875 /* Full heap sanity check. */
881 if (RtsFlags.GcFlags.generations == 1) {
882 checkHeap(g0s0->to_blocks);
883 checkChain(g0s0->large_objects);
886 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
887 for (s = 0; s < generations[g].n_steps; s++) {
888 ASSERT(countBlocks(generations[g].steps[s].blocks)
889 == generations[g].steps[s].n_blocks);
890 ASSERT(countBlocks(generations[g].steps[s].large_objects)
891 == generations[g].steps[s].n_large_blocks);
892 if (g == 0 && s == 0) { continue; }
893 checkHeap(generations[g].steps[s].blocks);
894 checkChain(generations[g].steps[s].large_objects);
896 checkMutableList(generations[g].mut_list, g);
900 checkFreeListSanity();
904 // handy function for use in gdb, because Bdescr() is inlined.
905 extern bdescr *_bdescr( StgPtr p );