1 /* "Bag-of-pages" garbage collector for the GNU compiler.
2 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009,
3 2010, 2011 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
28 #include "diagnostic-core.h"
31 #include "ggc-internal.h"
34 #include "tree-flow.h"
38 /* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a
39 file open. Prefer either to valloc. */
41 # undef HAVE_MMAP_DEV_ZERO
45 #ifdef HAVE_MMAP_DEV_ZERO
50 #define USING_MALLOC_PAGE_GROUPS
53 #if defined(HAVE_MADVISE) && HAVE_DECL_MADVISE && defined(MADV_DONTNEED) \
54 && defined(USING_MMAP)
55 # define USING_MADVISE
60 This garbage-collecting allocator allocates objects on one of a set
61 of pages. Each page can allocate objects of a single size only;
62 available sizes are powers of two starting at four bytes. The size
63 of an allocation request is rounded up to the next power of two
64 (`order'), and satisfied from the appropriate page.
66 Each page is recorded in a page-entry, which also maintains an
67 in-use bitmap of object positions on the page. This allows the
68 allocation state of a particular object to be flipped without
69 touching the page itself.
71 Each page-entry also has a context depth, which is used to track
72 pushing and popping of allocation contexts. Only objects allocated
73 in the current (highest-numbered) context may be collected.
75 Page entries are arranged in an array of singly-linked lists. The
76 array is indexed by the allocation size, in bits, of the pages on
77 it; i.e. all pages on a list allocate objects of the same size.
78 Pages are ordered on the list such that all non-full pages precede
79 all full pages, with non-full pages arranged in order of decreasing
82 Empty pages (of all orders) are kept on a single page cache list,
83 and are considered first when new pages are required; they are
84 deallocated at the start of the next collection if they haven't
85 been recycled by then. */
87 /* Define GGC_DEBUG_LEVEL to print debugging information.
88 0: No debugging output.
89 1: GC statistics only.
90 2: Page-entry allocations/deallocations as well.
91 3: Object allocations as well.
92 4: Object marks as well. */
93 #define GGC_DEBUG_LEVEL (0)
95 #ifndef HOST_BITS_PER_PTR
96 #define HOST_BITS_PER_PTR HOST_BITS_PER_LONG
100 /* A two-level tree is used to look up the page-entry for a given
101 pointer. Two chunks of the pointer's bits are extracted to index
102 the first and second levels of the tree, as follows:
106 msb +----------------+----+------+------+ lsb
112 The bottommost HOST_PAGE_SIZE_BITS are ignored, since page-entry
113 pages are aligned on system page boundaries. The next most
114 significant PAGE_L2_BITS and PAGE_L1_BITS are the second and first
115 index values in the lookup table, respectively.
117 For 32-bit architectures and the settings below, there are no
118 leftover bits. For architectures with wider pointers, the lookup
119 tree points to a list of pages, which must be scanned to find the
122 #define PAGE_L1_BITS (8)
123 #define PAGE_L2_BITS (32 - PAGE_L1_BITS - G.lg_pagesize)
124 #define PAGE_L1_SIZE ((uintptr_t) 1 << PAGE_L1_BITS)
125 #define PAGE_L2_SIZE ((uintptr_t) 1 << PAGE_L2_BITS)
127 #define LOOKUP_L1(p) \
128 (((uintptr_t) (p) >> (32 - PAGE_L1_BITS)) & ((1 << PAGE_L1_BITS) - 1))
130 #define LOOKUP_L2(p) \
131 (((uintptr_t) (p) >> G.lg_pagesize) & ((1 << PAGE_L2_BITS) - 1))
133 /* The number of objects per allocation page, for objects on a page of
134 the indicated ORDER. */
135 #define OBJECTS_PER_PAGE(ORDER) objects_per_page_table[ORDER]
137 /* The number of objects in P. */
138 #define OBJECTS_IN_PAGE(P) ((P)->bytes / OBJECT_SIZE ((P)->order))
140 /* The size of an object on a page of the indicated ORDER. */
141 #define OBJECT_SIZE(ORDER) object_size_table[ORDER]
143 /* For speed, we avoid doing a general integer divide to locate the
144 offset in the allocation bitmap, by precalculating numbers M, S
145 such that (O * M) >> S == O / Z (modulo 2^32), for any offset O
146 within the page which is evenly divisible by the object size Z. */
147 #define DIV_MULT(ORDER) inverse_table[ORDER].mult
148 #define DIV_SHIFT(ORDER) inverse_table[ORDER].shift
149 #define OFFSET_TO_BIT(OFFSET, ORDER) \
150 (((OFFSET) * DIV_MULT (ORDER)) >> DIV_SHIFT (ORDER))
152 /* We use this structure to determine the alignment required for
153 allocations. For power-of-two sized allocations, that's not a
154 problem, but it does matter for odd-sized allocations.
155 We do not care about alignment for floating-point types. */
157 struct max_alignment
{
165 /* The biggest alignment required. */
167 #define MAX_ALIGNMENT (offsetof (struct max_alignment, u))
170 /* The number of extra orders, not corresponding to power-of-two sized
173 #define NUM_EXTRA_ORDERS ARRAY_SIZE (extra_order_size_table)
175 #define RTL_SIZE(NSLOTS) \
176 (RTX_HDR_SIZE + (NSLOTS) * sizeof (rtunion))
178 #define TREE_EXP_SIZE(OPS) \
179 (sizeof (struct tree_exp) + ((OPS) - 1) * sizeof (tree))
181 /* The Ith entry is the maximum size of an object to be stored in the
182 Ith extra order. Adding a new entry to this array is the *only*
183 thing you need to do to add a new special allocation size. */
185 static const size_t extra_order_size_table
[] = {
186 /* Extra orders for small non-power-of-two multiples of MAX_ALIGNMENT.
187 There are a lot of structures with these sizes and explicitly
188 listing them risks orders being dropped because they changed size. */
200 sizeof (struct tree_decl_non_common
),
201 sizeof (struct tree_field_decl
),
202 sizeof (struct tree_parm_decl
),
203 sizeof (struct tree_var_decl
),
204 sizeof (struct tree_type_non_common
),
205 sizeof (struct function
),
206 sizeof (struct basic_block_def
),
207 sizeof (struct cgraph_node
),
208 sizeof (struct loop
),
211 /* The total number of orders. */
213 #define NUM_ORDERS (HOST_BITS_PER_PTR + NUM_EXTRA_ORDERS)
215 /* Compute the smallest nonnegative number which when added to X gives
218 #define ROUND_UP_VALUE(x, f) ((f) - 1 - ((f) - 1 + (x)) % (f))
220 /* Compute the smallest multiple of F that is >= X. */
222 #define ROUND_UP(x, f) (CEIL (x, f) * (f))
224 /* Round X to next multiple of the page size */
226 #define PAGE_ALIGN(x) (((x) + G.pagesize - 1) & ~(G.pagesize - 1))
228 /* The Ith entry is the number of objects on a page or order I. */
230 static unsigned objects_per_page_table
[NUM_ORDERS
];
232 /* The Ith entry is the size of an object on a page of order I. */
234 static size_t object_size_table
[NUM_ORDERS
];
236 /* The Ith entry is a pair of numbers (mult, shift) such that
237 ((k * mult) >> shift) mod 2^32 == (k / OBJECT_SIZE(I)) mod 2^32,
238 for all k evenly divisible by OBJECT_SIZE(I). */
245 inverse_table
[NUM_ORDERS
];
247 /* A page_entry records the status of an allocation page. This
248 structure is dynamically sized to fit the bitmap in_use_p. */
249 typedef struct page_entry
251 /* The next page-entry with objects of the same size, or NULL if
252 this is the last page-entry. */
253 struct page_entry
*next
;
255 /* The previous page-entry with objects of the same size, or NULL if
256 this is the first page-entry. The PREV pointer exists solely to
257 keep the cost of ggc_free manageable. */
258 struct page_entry
*prev
;
260 /* The number of bytes allocated. (This will always be a multiple
261 of the host system page size.) */
264 /* The address at which the memory is allocated. */
267 #ifdef USING_MALLOC_PAGE_GROUPS
268 /* Back pointer to the page group this page came from. */
269 struct page_group
*group
;
272 /* This is the index in the by_depth varray where this page table
274 unsigned long index_by_depth
;
276 /* Context depth of this page. */
277 unsigned short context_depth
;
279 /* The number of free objects remaining on this page. */
280 unsigned short num_free_objects
;
282 /* A likely candidate for the bit position of a free object for the
283 next allocation from this page. */
284 unsigned short next_bit_hint
;
286 /* The lg of size of objects allocated from this page. */
289 /* Discarded page? */
292 /* A bit vector indicating whether or not objects are in use. The
293 Nth bit is one if the Nth object on this page is allocated. This
294 array is dynamically sized. */
295 unsigned long in_use_p
[1];
298 #ifdef USING_MALLOC_PAGE_GROUPS
299 /* A page_group describes a large allocation from malloc, from which
300 we parcel out aligned pages. */
301 typedef struct page_group
303 /* A linked list of all extant page groups. */
304 struct page_group
*next
;
306 /* The address we received from malloc. */
309 /* The size of the block. */
312 /* A bitmask of pages in use. */
317 #if HOST_BITS_PER_PTR <= 32
319 /* On 32-bit hosts, we use a two level page table, as pictured above. */
320 typedef page_entry
**page_table
[PAGE_L1_SIZE
];
324 /* On 64-bit hosts, we use the same two level page tables plus a linked
325 list that disambiguates the top 32-bits. There will almost always be
326 exactly one entry in the list. */
327 typedef struct page_table_chain
329 struct page_table_chain
*next
;
331 page_entry
**table
[PAGE_L1_SIZE
];
336 #ifdef ENABLE_GC_ALWAYS_COLLECT
337 /* List of free objects to be verified as actually free on the
342 struct free_object
*next
;
346 /* The rest of the global variables. */
347 static struct globals
349 /* The Nth element in this array is a page with objects of size 2^N.
350 If there are any pages with free objects, they will be at the
351 head of the list. NULL if there are no page-entries for this
353 page_entry
*pages
[NUM_ORDERS
];
355 /* The Nth element in this array is the last page with objects of
356 size 2^N. NULL if there are no page-entries for this object
358 page_entry
*page_tails
[NUM_ORDERS
];
360 /* Lookup table for associating allocation pages with object addresses. */
363 /* The system's page size. */
367 /* Bytes currently allocated. */
370 /* Bytes currently allocated at the end of the last collection. */
371 size_t allocated_last_gc
;
373 /* Total amount of memory mapped. */
376 /* Bit N set if any allocations have been done at context depth N. */
377 unsigned long context_depth_allocations
;
379 /* Bit N set if any collections have been done at context depth N. */
380 unsigned long context_depth_collections
;
382 /* The current depth in the context stack. */
383 unsigned short context_depth
;
385 /* A file descriptor open to /dev/zero for reading. */
386 #if defined (HAVE_MMAP_DEV_ZERO)
390 /* A cache of free system pages. */
391 page_entry
*free_pages
;
393 #ifdef USING_MALLOC_PAGE_GROUPS
394 page_group
*page_groups
;
397 /* The file descriptor for debugging output. */
400 /* Current number of elements in use in depth below. */
401 unsigned int depth_in_use
;
403 /* Maximum number of elements that can be used before resizing. */
404 unsigned int depth_max
;
406 /* Each element of this array is an index in by_depth where the given
407 depth starts. This structure is indexed by that given depth we
408 are interested in. */
411 /* Current number of elements in use in by_depth below. */
412 unsigned int by_depth_in_use
;
414 /* Maximum number of elements that can be used before resizing. */
415 unsigned int by_depth_max
;
417 /* Each element of this array is a pointer to a page_entry, all
418 page_entries can be found in here by increasing depth.
419 index_by_depth in the page_entry is the index into this data
420 structure where that page_entry can be found. This is used to
421 speed up finding all page_entries at a particular depth. */
422 page_entry
**by_depth
;
424 /* Each element is a pointer to the saved in_use_p bits, if any,
425 zero otherwise. We allocate them all together, to enable a
426 better runtime data access pattern. */
427 unsigned long **save_in_use
;
429 #ifdef ENABLE_GC_ALWAYS_COLLECT
430 /* List of free objects to be verified as actually free on the
432 struct free_object
*free_object_list
;
437 /* Total GC-allocated memory. */
438 unsigned long long total_allocated
;
439 /* Total overhead for GC-allocated memory. */
440 unsigned long long total_overhead
;
442 /* Total allocations and overhead for sizes less than 32, 64 and 128.
443 These sizes are interesting because they are typical cache line
446 unsigned long long total_allocated_under32
;
447 unsigned long long total_overhead_under32
;
449 unsigned long long total_allocated_under64
;
450 unsigned long long total_overhead_under64
;
452 unsigned long long total_allocated_under128
;
453 unsigned long long total_overhead_under128
;
455 /* The allocations for each of the allocation orders. */
456 unsigned long long total_allocated_per_order
[NUM_ORDERS
];
458 /* The overhead for each of the allocation orders. */
459 unsigned long long total_overhead_per_order
[NUM_ORDERS
];
463 /* The size in bytes required to maintain a bitmap for the objects
465 #define BITMAP_SIZE(Num_objects) \
466 (CEIL ((Num_objects), HOST_BITS_PER_LONG) * sizeof(long))
468 /* Allocate pages in chunks of this size, to throttle calls to memory
469 allocation routines. The first page is used, the rest go onto the
470 free list. This cannot be larger than HOST_BITS_PER_INT for the
471 in_use bitmask for page_group. Hosts that need a different value
472 can override this by defining GGC_QUIRE_SIZE explicitly. */
473 #ifndef GGC_QUIRE_SIZE
475 # define GGC_QUIRE_SIZE 512 /* 2MB for 4K pages */
477 # define GGC_QUIRE_SIZE 16
481 /* Initial guess as to how many page table entries we might need. */
482 #define INITIAL_PTE_COUNT 128
484 static int ggc_allocated_p (const void *);
485 static page_entry
*lookup_page_table_entry (const void *);
486 static void set_page_table_entry (void *, page_entry
*);
488 static char *alloc_anon (char *, size_t, bool check
);
490 #ifdef USING_MALLOC_PAGE_GROUPS
491 static size_t page_group_index (char *, char *);
492 static void set_page_group_in_use (page_group
*, char *);
493 static void clear_page_group_in_use (page_group
*, char *);
495 static struct page_entry
* alloc_page (unsigned);
496 static void free_page (struct page_entry
*);
497 static void release_pages (void);
498 static void clear_marks (void);
499 static void sweep_pages (void);
500 static void ggc_recalculate_in_use_p (page_entry
*);
501 static void compute_inverse (unsigned);
502 static inline void adjust_depth (void);
503 static void move_ptes_to_front (int, int);
505 void debug_print_page_list (int);
506 static void push_depth (unsigned int);
507 static void push_by_depth (page_entry
*, unsigned long *);
509 /* Push an entry onto G.depth. */
512 push_depth (unsigned int i
)
514 if (G
.depth_in_use
>= G
.depth_max
)
517 G
.depth
= XRESIZEVEC (unsigned int, G
.depth
, G
.depth_max
);
519 G
.depth
[G
.depth_in_use
++] = i
;
522 /* Push an entry onto G.by_depth and G.save_in_use. */
525 push_by_depth (page_entry
*p
, unsigned long *s
)
527 if (G
.by_depth_in_use
>= G
.by_depth_max
)
530 G
.by_depth
= XRESIZEVEC (page_entry
*, G
.by_depth
, G
.by_depth_max
);
531 G
.save_in_use
= XRESIZEVEC (unsigned long *, G
.save_in_use
,
534 G
.by_depth
[G
.by_depth_in_use
] = p
;
535 G
.save_in_use
[G
.by_depth_in_use
++] = s
;
538 #if (GCC_VERSION < 3001)
539 #define prefetch(X) ((void) X)
541 #define prefetch(X) __builtin_prefetch (X)
544 #define save_in_use_p_i(__i) \
546 #define save_in_use_p(__p) \
547 (save_in_use_p_i (__p->index_by_depth))
549 /* Returns nonzero if P was allocated in GC'able memory. */
552 ggc_allocated_p (const void *p
)
557 #if HOST_BITS_PER_PTR <= 32
560 page_table table
= G
.lookup
;
561 uintptr_t high_bits
= (uintptr_t) p
& ~ (uintptr_t) 0xffffffff;
566 if (table
->high_bits
== high_bits
)
570 base
= &table
->table
[0];
573 /* Extract the level 1 and 2 indices. */
577 return base
[L1
] && base
[L1
][L2
];
580 /* Traverse the page table and find the entry for a page.
581 Die (probably) if the object wasn't allocated via GC. */
583 static inline page_entry
*
584 lookup_page_table_entry (const void *p
)
589 #if HOST_BITS_PER_PTR <= 32
592 page_table table
= G
.lookup
;
593 uintptr_t high_bits
= (uintptr_t) p
& ~ (uintptr_t) 0xffffffff;
594 while (table
->high_bits
!= high_bits
)
596 base
= &table
->table
[0];
599 /* Extract the level 1 and 2 indices. */
606 /* Set the page table entry for a page. */
609 set_page_table_entry (void *p
, page_entry
*entry
)
614 #if HOST_BITS_PER_PTR <= 32
618 uintptr_t high_bits
= (uintptr_t) p
& ~ (uintptr_t) 0xffffffff;
619 for (table
= G
.lookup
; table
; table
= table
->next
)
620 if (table
->high_bits
== high_bits
)
623 /* Not found -- allocate a new table. */
624 table
= XCNEW (struct page_table_chain
);
625 table
->next
= G
.lookup
;
626 table
->high_bits
= high_bits
;
629 base
= &table
->table
[0];
632 /* Extract the level 1 and 2 indices. */
636 if (base
[L1
] == NULL
)
637 base
[L1
] = XCNEWVEC (page_entry
*, PAGE_L2_SIZE
);
639 base
[L1
][L2
] = entry
;
642 /* Prints the page-entry for object size ORDER, for debugging. */
645 debug_print_page_list (int order
)
648 printf ("Head=%p, Tail=%p:\n", (void *) G
.pages
[order
],
649 (void *) G
.page_tails
[order
]);
653 printf ("%p(%1d|%3d) -> ", (void *) p
, p
->context_depth
,
654 p
->num_free_objects
);
662 /* Allocate SIZE bytes of anonymous memory, preferably near PREF,
663 (if non-null). The ifdef structure here is intended to cause a
664 compile error unless exactly one of the HAVE_* is defined. */
667 alloc_anon (char *pref ATTRIBUTE_UNUSED
, size_t size
, bool check
)
669 #ifdef HAVE_MMAP_ANON
670 char *page
= (char *) mmap (pref
, size
, PROT_READ
| PROT_WRITE
,
671 MAP_PRIVATE
| MAP_ANONYMOUS
, -1, 0);
673 #ifdef HAVE_MMAP_DEV_ZERO
674 char *page
= (char *) mmap (pref
, size
, PROT_READ
| PROT_WRITE
,
675 MAP_PRIVATE
, G
.dev_zero_fd
, 0);
678 if (page
== (char *) MAP_FAILED
)
682 perror ("virtual memory exhausted");
683 exit (FATAL_EXIT_CODE
);
686 /* Remember that we allocated this memory. */
687 G
.bytes_mapped
+= size
;
689 /* Pretend we don't have access to the allocated pages. We'll enable
690 access to smaller pieces of the area in ggc_internal_alloc. Discard the
691 handle to avoid handle leak. */
692 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (page
, size
));
697 #ifdef USING_MALLOC_PAGE_GROUPS
698 /* Compute the index for this page into the page group. */
701 page_group_index (char *allocation
, char *page
)
703 return (size_t) (page
- allocation
) >> G
.lg_pagesize
;
706 /* Set and clear the in_use bit for this page in the page group. */
709 set_page_group_in_use (page_group
*group
, char *page
)
711 group
->in_use
|= 1 << page_group_index (group
->allocation
, page
);
715 clear_page_group_in_use (page_group
*group
, char *page
)
717 group
->in_use
&= ~(1 << page_group_index (group
->allocation
, page
));
721 /* Allocate a new page for allocating objects of size 2^ORDER,
722 and return an entry for it. The entry is not added to the
723 appropriate page_table list. */
725 static inline struct page_entry
*
726 alloc_page (unsigned order
)
728 struct page_entry
*entry
, *p
, **pp
;
732 size_t page_entry_size
;
734 #ifdef USING_MALLOC_PAGE_GROUPS
738 num_objects
= OBJECTS_PER_PAGE (order
);
739 bitmap_size
= BITMAP_SIZE (num_objects
+ 1);
740 page_entry_size
= sizeof (page_entry
) - sizeof (long) + bitmap_size
;
741 entry_size
= num_objects
* OBJECT_SIZE (order
);
742 if (entry_size
< G
.pagesize
)
743 entry_size
= G
.pagesize
;
744 entry_size
= PAGE_ALIGN (entry_size
);
749 /* Check the list of free pages for one we can use. */
750 for (pp
= &G
.free_pages
, p
= *pp
; p
; pp
= &p
->next
, p
= *pp
)
751 if (p
->bytes
== entry_size
)
757 G
.bytes_mapped
+= p
->bytes
;
758 p
->discarded
= false;
760 /* Recycle the allocated memory from this page ... */
764 #ifdef USING_MALLOC_PAGE_GROUPS
768 /* ... and, if possible, the page entry itself. */
769 if (p
->order
== order
)
772 memset (entry
, 0, page_entry_size
);
778 else if (entry_size
== G
.pagesize
)
780 /* We want just one page. Allocate a bunch of them and put the
781 extras on the freelist. (Can only do this optimization with
782 mmap for backing store.) */
783 struct page_entry
*e
, *f
= G
.free_pages
;
784 int i
, entries
= GGC_QUIRE_SIZE
;
786 page
= alloc_anon (NULL
, G
.pagesize
* GGC_QUIRE_SIZE
, false);
789 page
= alloc_anon(NULL
, G
.pagesize
, true);
793 /* This loop counts down so that the chain will be in ascending
795 for (i
= entries
- 1; i
>= 1; i
--)
797 e
= XCNEWVAR (struct page_entry
, page_entry_size
);
799 e
->bytes
= G
.pagesize
;
800 e
->page
= page
+ (i
<< G
.lg_pagesize
);
808 page
= alloc_anon (NULL
, entry_size
, true);
810 #ifdef USING_MALLOC_PAGE_GROUPS
813 /* Allocate a large block of memory and serve out the aligned
814 pages therein. This results in much less memory wastage
815 than the traditional implementation of valloc. */
817 char *allocation
, *a
, *enda
;
818 size_t alloc_size
, head_slop
, tail_slop
;
819 int multiple_pages
= (entry_size
== G
.pagesize
);
822 alloc_size
= GGC_QUIRE_SIZE
* G
.pagesize
;
824 alloc_size
= entry_size
+ G
.pagesize
- 1;
825 allocation
= XNEWVEC (char, alloc_size
);
827 page
= (char *) (((uintptr_t) allocation
+ G
.pagesize
- 1) & -G
.pagesize
);
828 head_slop
= page
- allocation
;
830 tail_slop
= ((size_t) allocation
+ alloc_size
) & (G
.pagesize
- 1);
832 tail_slop
= alloc_size
- entry_size
- head_slop
;
833 enda
= allocation
+ alloc_size
- tail_slop
;
835 /* We allocated N pages, which are likely not aligned, leaving
836 us with N-1 usable pages. We plan to place the page_group
837 structure somewhere in the slop. */
838 if (head_slop
>= sizeof (page_group
))
839 group
= (page_group
*)page
- 1;
842 /* We magically got an aligned allocation. Too bad, we have
843 to waste a page anyway. */
847 tail_slop
+= G
.pagesize
;
849 gcc_assert (tail_slop
>= sizeof (page_group
));
850 group
= (page_group
*)enda
;
851 tail_slop
-= sizeof (page_group
);
854 /* Remember that we allocated this memory. */
855 group
->next
= G
.page_groups
;
856 group
->allocation
= allocation
;
857 group
->alloc_size
= alloc_size
;
859 G
.page_groups
= group
;
860 G
.bytes_mapped
+= alloc_size
;
862 /* If we allocated multiple pages, put the rest on the free list. */
865 struct page_entry
*e
, *f
= G
.free_pages
;
866 for (a
= enda
- G
.pagesize
; a
!= page
; a
-= G
.pagesize
)
868 e
= XCNEWVAR (struct page_entry
, page_entry_size
);
870 e
->bytes
= G
.pagesize
;
882 entry
= XCNEWVAR (struct page_entry
, page_entry_size
);
884 entry
->bytes
= entry_size
;
886 entry
->context_depth
= G
.context_depth
;
887 entry
->order
= order
;
888 entry
->num_free_objects
= num_objects
;
889 entry
->next_bit_hint
= 1;
891 G
.context_depth_allocations
|= (unsigned long)1 << G
.context_depth
;
893 #ifdef USING_MALLOC_PAGE_GROUPS
894 entry
->group
= group
;
895 set_page_group_in_use (group
, page
);
898 /* Set the one-past-the-end in-use bit. This acts as a sentry as we
899 increment the hint. */
900 entry
->in_use_p
[num_objects
/ HOST_BITS_PER_LONG
]
901 = (unsigned long) 1 << (num_objects
% HOST_BITS_PER_LONG
);
903 set_page_table_entry (page
, entry
);
905 if (GGC_DEBUG_LEVEL
>= 2)
906 fprintf (G
.debug_file
,
907 "Allocating page at %p, object size=%lu, data %p-%p\n",
908 (void *) entry
, (unsigned long) OBJECT_SIZE (order
), page
,
909 page
+ entry_size
- 1);
914 /* Adjust the size of G.depth so that no index greater than the one
915 used by the top of the G.by_depth is used. */
922 if (G
.by_depth_in_use
)
924 top
= G
.by_depth
[G
.by_depth_in_use
-1];
926 /* Peel back indices in depth that index into by_depth, so that
927 as new elements are added to by_depth, we note the indices
928 of those elements, if they are for new context depths. */
929 while (G
.depth_in_use
> (size_t)top
->context_depth
+1)
934 /* For a page that is no longer needed, put it on the free page list. */
937 free_page (page_entry
*entry
)
939 if (GGC_DEBUG_LEVEL
>= 2)
940 fprintf (G
.debug_file
,
941 "Deallocating page at %p, data %p-%p\n", (void *) entry
,
942 entry
->page
, entry
->page
+ entry
->bytes
- 1);
944 /* Mark the page as inaccessible. Discard the handle to avoid handle
946 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (entry
->page
, entry
->bytes
));
948 set_page_table_entry (entry
->page
, NULL
);
950 #ifdef USING_MALLOC_PAGE_GROUPS
951 clear_page_group_in_use (entry
->group
, entry
->page
);
954 if (G
.by_depth_in_use
> 1)
956 page_entry
*top
= G
.by_depth
[G
.by_depth_in_use
-1];
957 int i
= entry
->index_by_depth
;
959 /* We cannot free a page from a context deeper than the current
961 gcc_assert (entry
->context_depth
== top
->context_depth
);
963 /* Put top element into freed slot. */
965 G
.save_in_use
[i
] = G
.save_in_use
[G
.by_depth_in_use
-1];
966 top
->index_by_depth
= i
;
972 entry
->next
= G
.free_pages
;
973 G
.free_pages
= entry
;
976 /* Release the free page cache to the system. */
982 page_entry
*p
, *start_p
;
986 page_entry
*next
, *prev
, *newprev
;
987 size_t free_unit
= (GGC_QUIRE_SIZE
/2) * G
.pagesize
;
989 /* First free larger continuous areas to the OS.
990 This allows other allocators to grab these areas if needed.
991 This is only done on larger chunks to avoid fragmentation.
992 This does not always work because the free_pages list is only
993 approximately sorted. */
1004 while (p
&& p
->page
== start
+ len
)
1008 mapped_len
+= p
->bytes
;
1012 if (len
>= free_unit
)
1014 while (start_p
!= p
)
1016 next
= start_p
->next
;
1020 munmap (start
, len
);
1025 G
.bytes_mapped
-= mapped_len
;
1031 /* Now give back the fragmented pages to the OS, but keep the address
1032 space to reuse it next time. */
1034 for (p
= G
.free_pages
; p
; )
1045 while (p
&& p
->page
== start
+ len
)
1050 /* Give the page back to the kernel, but don't free the mapping.
1051 This avoids fragmentation in the virtual memory map of the
1052 process. Next time we can reuse it by just touching it. */
1053 madvise (start
, len
, MADV_DONTNEED
);
1054 /* Don't count those pages as mapped to not touch the garbage collector
1056 G
.bytes_mapped
-= len
;
1057 while (start_p
!= p
)
1059 start_p
->discarded
= true;
1060 start_p
= start_p
->next
;
1064 #if defined(USING_MMAP) && !defined(USING_MADVISE)
1065 page_entry
*p
, *next
;
1069 /* Gather up adjacent pages so they are unmapped together. */
1080 while (p
&& p
->page
== start
+ len
)
1088 munmap (start
, len
);
1089 G
.bytes_mapped
-= len
;
1092 G
.free_pages
= NULL
;
1094 #ifdef USING_MALLOC_PAGE_GROUPS
1095 page_entry
**pp
, *p
;
1096 page_group
**gp
, *g
;
1098 /* Remove all pages from free page groups from the list. */
1100 while ((p
= *pp
) != NULL
)
1101 if (p
->group
->in_use
== 0)
1109 /* Remove all free page groups, and release the storage. */
1110 gp
= &G
.page_groups
;
1111 while ((g
= *gp
) != NULL
)
1115 G
.bytes_mapped
-= g
->alloc_size
;
1116 free (g
->allocation
);
1123 /* This table provides a fast way to determine ceil(log_2(size)) for
1124 allocation requests. The minimum allocation size is eight bytes. */
1125 #define NUM_SIZE_LOOKUP 512
1126 static unsigned char size_lookup
[NUM_SIZE_LOOKUP
] =
1128 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4,
1129 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
1130 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
1131 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
1132 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1133 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1134 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1135 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1136 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1137 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1138 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1139 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1140 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1141 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1142 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1143 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
1144 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1145 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1146 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1147 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1148 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1149 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1150 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1151 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1152 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1153 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1154 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1155 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1156 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1157 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1158 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
1159 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
1162 /* For a given size of memory requested for allocation, return the
1163 actual size that is going to be allocated, as well as the size
1167 ggc_round_alloc_size_1 (size_t requested_size
,
1169 size_t *alloced_size
)
1171 size_t order
, object_size
;
1173 if (requested_size
< NUM_SIZE_LOOKUP
)
1175 order
= size_lookup
[requested_size
];
1176 object_size
= OBJECT_SIZE (order
);
1181 while (requested_size
> (object_size
= OBJECT_SIZE (order
)))
1186 *size_order
= order
;
1188 *alloced_size
= object_size
;
1191 /* For a given size of memory requested for allocation, return the
1192 actual size that is going to be allocated. */
1195 ggc_round_alloc_size (size_t requested_size
)
1199 ggc_round_alloc_size_1 (requested_size
, NULL
, &size
);
1203 /* Typed allocation function. Does nothing special in this collector. */
1206 ggc_alloc_typed_stat (enum gt_types_enum type ATTRIBUTE_UNUSED
, size_t size
1209 return ggc_internal_alloc_stat (size PASS_MEM_STAT
);
1212 /* Allocate a chunk of memory of SIZE bytes. Its contents are undefined. */
1215 ggc_internal_alloc_stat (size_t size MEM_STAT_DECL
)
1217 size_t order
, word
, bit
, object_offset
, object_size
;
1218 struct page_entry
*entry
;
1221 ggc_round_alloc_size_1 (size
, &order
, &object_size
);
1223 /* If there are non-full pages for this size allocation, they are at
1224 the head of the list. */
1225 entry
= G
.pages
[order
];
1227 /* If there is no page for this object size, or all pages in this
1228 context are full, allocate a new page. */
1229 if (entry
== NULL
|| entry
->num_free_objects
== 0)
1231 struct page_entry
*new_entry
;
1232 new_entry
= alloc_page (order
);
1234 new_entry
->index_by_depth
= G
.by_depth_in_use
;
1235 push_by_depth (new_entry
, 0);
1237 /* We can skip context depths, if we do, make sure we go all the
1238 way to the new depth. */
1239 while (new_entry
->context_depth
>= G
.depth_in_use
)
1240 push_depth (G
.by_depth_in_use
-1);
1242 /* If this is the only entry, it's also the tail. If it is not
1243 the only entry, then we must update the PREV pointer of the
1244 ENTRY (G.pages[order]) to point to our new page entry. */
1246 G
.page_tails
[order
] = new_entry
;
1248 entry
->prev
= new_entry
;
1250 /* Put new pages at the head of the page list. By definition the
1251 entry at the head of the list always has a NULL pointer. */
1252 new_entry
->next
= entry
;
1253 new_entry
->prev
= NULL
;
1255 G
.pages
[order
] = new_entry
;
1257 /* For a new page, we know the word and bit positions (in the
1258 in_use bitmap) of the first available object -- they're zero. */
1259 new_entry
->next_bit_hint
= 1;
1266 /* First try to use the hint left from the previous allocation
1267 to locate a clear bit in the in-use bitmap. We've made sure
1268 that the one-past-the-end bit is always set, so if the hint
1269 has run over, this test will fail. */
1270 unsigned hint
= entry
->next_bit_hint
;
1271 word
= hint
/ HOST_BITS_PER_LONG
;
1272 bit
= hint
% HOST_BITS_PER_LONG
;
1274 /* If the hint didn't work, scan the bitmap from the beginning. */
1275 if ((entry
->in_use_p
[word
] >> bit
) & 1)
1278 while (~entry
->in_use_p
[word
] == 0)
1281 #if GCC_VERSION >= 3004
1282 bit
= __builtin_ctzl (~entry
->in_use_p
[word
]);
1284 while ((entry
->in_use_p
[word
] >> bit
) & 1)
1288 hint
= word
* HOST_BITS_PER_LONG
+ bit
;
1291 /* Next time, try the next bit. */
1292 entry
->next_bit_hint
= hint
+ 1;
1294 object_offset
= hint
* object_size
;
1297 /* Set the in-use bit. */
1298 entry
->in_use_p
[word
] |= ((unsigned long) 1 << bit
);
1300 /* Keep a running total of the number of free objects. If this page
1301 fills up, we may have to move it to the end of the list if the
1302 next page isn't full. If the next page is full, all subsequent
1303 pages are full, so there's no need to move it. */
1304 if (--entry
->num_free_objects
== 0
1305 && entry
->next
!= NULL
1306 && entry
->next
->num_free_objects
> 0)
1308 /* We have a new head for the list. */
1309 G
.pages
[order
] = entry
->next
;
1311 /* We are moving ENTRY to the end of the page table list.
1312 The new page at the head of the list will have NULL in
1313 its PREV field and ENTRY will have NULL in its NEXT field. */
1314 entry
->next
->prev
= NULL
;
1317 /* Append ENTRY to the tail of the list. */
1318 entry
->prev
= G
.page_tails
[order
];
1319 G
.page_tails
[order
]->next
= entry
;
1320 G
.page_tails
[order
] = entry
;
1323 /* Calculate the object's address. */
1324 result
= entry
->page
+ object_offset
;
1325 if (GATHER_STATISTICS
)
1326 ggc_record_overhead (OBJECT_SIZE (order
), OBJECT_SIZE (order
) - size
,
1327 result FINAL_PASS_MEM_STAT
);
1329 #ifdef ENABLE_GC_CHECKING
1330 /* Keep poisoning-by-writing-0xaf the object, in an attempt to keep the
1331 exact same semantics in presence of memory bugs, regardless of
1332 ENABLE_VALGRIND_CHECKING. We override this request below. Drop the
1333 handle to avoid handle leak. */
1334 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result
, object_size
));
1336 /* `Poison' the entire allocated object, including any padding at
1338 memset (result
, 0xaf, object_size
);
1340 /* Make the bytes after the end of the object unaccessible. Discard the
1341 handle to avoid handle leak. */
1342 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *) result
+ size
,
1343 object_size
- size
));
1346 /* Tell Valgrind that the memory is there, but its content isn't
1347 defined. The bytes at the end of the object are still marked
1349 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result
, size
));
1351 /* Keep track of how many bytes are being allocated. This
1352 information is used in deciding when to collect. */
1353 G
.allocated
+= object_size
;
1355 /* For timevar statistics. */
1356 timevar_ggc_mem_total
+= object_size
;
1358 if (GATHER_STATISTICS
)
1360 size_t overhead
= object_size
- size
;
1362 G
.stats
.total_overhead
+= overhead
;
1363 G
.stats
.total_allocated
+= object_size
;
1364 G
.stats
.total_overhead_per_order
[order
] += overhead
;
1365 G
.stats
.total_allocated_per_order
[order
] += object_size
;
1369 G
.stats
.total_overhead_under32
+= overhead
;
1370 G
.stats
.total_allocated_under32
+= object_size
;
1374 G
.stats
.total_overhead_under64
+= overhead
;
1375 G
.stats
.total_allocated_under64
+= object_size
;
1379 G
.stats
.total_overhead_under128
+= overhead
;
1380 G
.stats
.total_allocated_under128
+= object_size
;
1384 if (GGC_DEBUG_LEVEL
>= 3)
1385 fprintf (G
.debug_file
,
1386 "Allocating object, requested size=%lu, actual=%lu at %p on %p\n",
1387 (unsigned long) size
, (unsigned long) object_size
, result
,
1393 /* Mark function for strings. */
1396 gt_ggc_m_S (const void *p
)
1401 unsigned long offset
;
1403 if (!p
|| !ggc_allocated_p (p
))
1406 /* Look up the page on which the object is alloced. . */
1407 entry
= lookup_page_table_entry (p
);
1410 /* Calculate the index of the object on the page; this is its bit
1411 position in the in_use_p bitmap. Note that because a char* might
1412 point to the middle of an object, we need special code here to
1413 make sure P points to the start of an object. */
1414 offset
= ((const char *) p
- entry
->page
) % object_size_table
[entry
->order
];
1417 /* Here we've seen a char* which does not point to the beginning
1418 of an allocated object. We assume it points to the middle of
1420 gcc_assert (offset
== offsetof (struct tree_string
, str
));
1421 p
= ((const char *) p
) - offset
;
1422 gt_ggc_mx_lang_tree_node (CONST_CAST (void *, p
));
1426 bit
= OFFSET_TO_BIT (((const char *) p
) - entry
->page
, entry
->order
);
1427 word
= bit
/ HOST_BITS_PER_LONG
;
1428 mask
= (unsigned long) 1 << (bit
% HOST_BITS_PER_LONG
);
1430 /* If the bit was previously set, skip it. */
1431 if (entry
->in_use_p
[word
] & mask
)
1434 /* Otherwise set it, and decrement the free object count. */
1435 entry
->in_use_p
[word
] |= mask
;
1436 entry
->num_free_objects
-= 1;
1438 if (GGC_DEBUG_LEVEL
>= 4)
1439 fprintf (G
.debug_file
, "Marking %p\n", p
);
1444 /* If P is not marked, marks it and return false. Otherwise return true.
1445 P must have been allocated by the GC allocator; it mustn't point to
1446 static objects, stack variables, or memory allocated with malloc. */
1449 ggc_set_mark (const void *p
)
1455 /* Look up the page on which the object is alloced. If the object
1456 wasn't allocated by the collector, we'll probably die. */
1457 entry
= lookup_page_table_entry (p
);
1460 /* Calculate the index of the object on the page; this is its bit
1461 position in the in_use_p bitmap. */
1462 bit
= OFFSET_TO_BIT (((const char *) p
) - entry
->page
, entry
->order
);
1463 word
= bit
/ HOST_BITS_PER_LONG
;
1464 mask
= (unsigned long) 1 << (bit
% HOST_BITS_PER_LONG
);
1466 /* If the bit was previously set, skip it. */
1467 if (entry
->in_use_p
[word
] & mask
)
1470 /* Otherwise set it, and decrement the free object count. */
1471 entry
->in_use_p
[word
] |= mask
;
1472 entry
->num_free_objects
-= 1;
1474 if (GGC_DEBUG_LEVEL
>= 4)
1475 fprintf (G
.debug_file
, "Marking %p\n", p
);
1480 /* Return 1 if P has been marked, zero otherwise.
1481 P must have been allocated by the GC allocator; it mustn't point to
1482 static objects, stack variables, or memory allocated with malloc. */
1485 ggc_marked_p (const void *p
)
1491 /* Look up the page on which the object is alloced. If the object
1492 wasn't allocated by the collector, we'll probably die. */
1493 entry
= lookup_page_table_entry (p
);
1496 /* Calculate the index of the object on the page; this is its bit
1497 position in the in_use_p bitmap. */
1498 bit
= OFFSET_TO_BIT (((const char *) p
) - entry
->page
, entry
->order
);
1499 word
= bit
/ HOST_BITS_PER_LONG
;
1500 mask
= (unsigned long) 1 << (bit
% HOST_BITS_PER_LONG
);
1502 return (entry
->in_use_p
[word
] & mask
) != 0;
1505 /* Return the size of the gc-able object P. */
1508 ggc_get_size (const void *p
)
1510 page_entry
*pe
= lookup_page_table_entry (p
);
1511 return OBJECT_SIZE (pe
->order
);
1514 /* Release the memory for object P. */
1519 page_entry
*pe
= lookup_page_table_entry (p
);
1520 size_t order
= pe
->order
;
1521 size_t size
= OBJECT_SIZE (order
);
1523 if (GATHER_STATISTICS
)
1524 ggc_free_overhead (p
);
1526 if (GGC_DEBUG_LEVEL
>= 3)
1527 fprintf (G
.debug_file
,
1528 "Freeing object, actual size=%lu, at %p on %p\n",
1529 (unsigned long) size
, p
, (void *) pe
);
1531 #ifdef ENABLE_GC_CHECKING
1532 /* Poison the data, to indicate the data is garbage. */
1533 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (p
, size
));
1534 memset (p
, 0xa5, size
);
1536 /* Let valgrind know the object is free. */
1537 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (p
, size
));
1539 #ifdef ENABLE_GC_ALWAYS_COLLECT
1540 /* In the completely-anal-checking mode, we do *not* immediately free
1541 the data, but instead verify that the data is *actually* not
1542 reachable the next time we collect. */
1544 struct free_object
*fo
= XNEW (struct free_object
);
1546 fo
->next
= G
.free_object_list
;
1547 G
.free_object_list
= fo
;
1551 unsigned int bit_offset
, word
, bit
;
1553 G
.allocated
-= size
;
1555 /* Mark the object not-in-use. */
1556 bit_offset
= OFFSET_TO_BIT (((const char *) p
) - pe
->page
, order
);
1557 word
= bit_offset
/ HOST_BITS_PER_LONG
;
1558 bit
= bit_offset
% HOST_BITS_PER_LONG
;
1559 pe
->in_use_p
[word
] &= ~(1UL << bit
);
1561 if (pe
->num_free_objects
++ == 0)
1565 /* If the page is completely full, then it's supposed to
1566 be after all pages that aren't. Since we've freed one
1567 object from a page that was full, we need to move the
1568 page to the head of the list.
1570 PE is the node we want to move. Q is the previous node
1571 and P is the next node in the list. */
1573 if (q
&& q
->num_free_objects
== 0)
1579 /* If PE was at the end of the list, then Q becomes the
1580 new end of the list. If PE was not the end of the
1581 list, then we need to update the PREV field for P. */
1583 G
.page_tails
[order
] = q
;
1587 /* Move PE to the head of the list. */
1588 pe
->next
= G
.pages
[order
];
1590 G
.pages
[order
]->prev
= pe
;
1591 G
.pages
[order
] = pe
;
1594 /* Reset the hint bit to point to the only free object. */
1595 pe
->next_bit_hint
= bit_offset
;
1601 /* Subroutine of init_ggc which computes the pair of numbers used to
1602 perform division by OBJECT_SIZE (order) and fills in inverse_table[].
1604 This algorithm is taken from Granlund and Montgomery's paper
1605 "Division by Invariant Integers using Multiplication"
1606 (Proc. SIGPLAN PLDI, 1994), section 9 (Exact division by
1610 compute_inverse (unsigned order
)
1615 size
= OBJECT_SIZE (order
);
1617 while (size
% 2 == 0)
1624 while (inv
* size
!= 1)
1625 inv
= inv
* (2 - inv
*size
);
1627 DIV_MULT (order
) = inv
;
1628 DIV_SHIFT (order
) = e
;
1631 /* Initialize the ggc-mmap allocator. */
1637 G
.pagesize
= getpagesize();
1638 G
.lg_pagesize
= exact_log2 (G
.pagesize
);
1640 #ifdef HAVE_MMAP_DEV_ZERO
1641 G
.dev_zero_fd
= open ("/dev/zero", O_RDONLY
);
1642 if (G
.dev_zero_fd
== -1)
1643 internal_error ("open /dev/zero: %m");
1647 G
.debug_file
= fopen ("ggc-mmap.debug", "w");
1649 G
.debug_file
= stdout
;
1653 /* StunOS has an amazing off-by-one error for the first mmap allocation
1654 after fiddling with RLIMIT_STACK. The result, as hard as it is to
1655 believe, is an unaligned page allocation, which would cause us to
1656 hork badly if we tried to use it. */
1658 char *p
= alloc_anon (NULL
, G
.pagesize
, true);
1659 struct page_entry
*e
;
1660 if ((uintptr_t)p
& (G
.pagesize
- 1))
1662 /* How losing. Discard this one and try another. If we still
1663 can't get something useful, give up. */
1665 p
= alloc_anon (NULL
, G
.pagesize
, true);
1666 gcc_assert (!((uintptr_t)p
& (G
.pagesize
- 1)));
1669 /* We have a good page, might as well hold onto it... */
1670 e
= XCNEW (struct page_entry
);
1671 e
->bytes
= G
.pagesize
;
1673 e
->next
= G
.free_pages
;
1678 /* Initialize the object size table. */
1679 for (order
= 0; order
< HOST_BITS_PER_PTR
; ++order
)
1680 object_size_table
[order
] = (size_t) 1 << order
;
1681 for (order
= HOST_BITS_PER_PTR
; order
< NUM_ORDERS
; ++order
)
1683 size_t s
= extra_order_size_table
[order
- HOST_BITS_PER_PTR
];
1685 /* If S is not a multiple of the MAX_ALIGNMENT, then round it up
1686 so that we're sure of getting aligned memory. */
1687 s
= ROUND_UP (s
, MAX_ALIGNMENT
);
1688 object_size_table
[order
] = s
;
1691 /* Initialize the objects-per-page and inverse tables. */
1692 for (order
= 0; order
< NUM_ORDERS
; ++order
)
1694 objects_per_page_table
[order
] = G
.pagesize
/ OBJECT_SIZE (order
);
1695 if (objects_per_page_table
[order
] == 0)
1696 objects_per_page_table
[order
] = 1;
1697 compute_inverse (order
);
1700 /* Reset the size_lookup array to put appropriately sized objects in
1701 the special orders. All objects bigger than the previous power
1702 of two, but no greater than the special size, should go in the
1704 for (order
= HOST_BITS_PER_PTR
; order
< NUM_ORDERS
; ++order
)
1709 i
= OBJECT_SIZE (order
);
1710 if (i
>= NUM_SIZE_LOOKUP
)
1713 for (o
= size_lookup
[i
]; o
== size_lookup
[i
]; --i
)
1714 size_lookup
[i
] = order
;
1719 G
.depth
= XNEWVEC (unsigned int, G
.depth_max
);
1721 G
.by_depth_in_use
= 0;
1722 G
.by_depth_max
= INITIAL_PTE_COUNT
;
1723 G
.by_depth
= XNEWVEC (page_entry
*, G
.by_depth_max
);
1724 G
.save_in_use
= XNEWVEC (unsigned long *, G
.by_depth_max
);
1727 /* Merge the SAVE_IN_USE_P and IN_USE_P arrays in P so that IN_USE_P
1728 reflects reality. Recalculate NUM_FREE_OBJECTS as well. */
1731 ggc_recalculate_in_use_p (page_entry
*p
)
1736 /* Because the past-the-end bit in in_use_p is always set, we
1737 pretend there is one additional object. */
1738 num_objects
= OBJECTS_IN_PAGE (p
) + 1;
1740 /* Reset the free object count. */
1741 p
->num_free_objects
= num_objects
;
1743 /* Combine the IN_USE_P and SAVE_IN_USE_P arrays. */
1745 i
< CEIL (BITMAP_SIZE (num_objects
),
1746 sizeof (*p
->in_use_p
));
1751 /* Something is in use if it is marked, or if it was in use in a
1752 context further down the context stack. */
1753 p
->in_use_p
[i
] |= save_in_use_p (p
)[i
];
1755 /* Decrement the free object count for every object allocated. */
1756 for (j
= p
->in_use_p
[i
]; j
; j
>>= 1)
1757 p
->num_free_objects
-= (j
& 1);
1760 gcc_assert (p
->num_free_objects
< num_objects
);
1763 /* Unmark all objects. */
1770 for (order
= 2; order
< NUM_ORDERS
; order
++)
1774 for (p
= G
.pages
[order
]; p
!= NULL
; p
= p
->next
)
1776 size_t num_objects
= OBJECTS_IN_PAGE (p
);
1777 size_t bitmap_size
= BITMAP_SIZE (num_objects
+ 1);
1779 /* The data should be page-aligned. */
1780 gcc_assert (!((uintptr_t) p
->page
& (G
.pagesize
- 1)));
1782 /* Pages that aren't in the topmost context are not collected;
1783 nevertheless, we need their in-use bit vectors to store GC
1784 marks. So, back them up first. */
1785 if (p
->context_depth
< G
.context_depth
)
1787 if (! save_in_use_p (p
))
1788 save_in_use_p (p
) = XNEWVAR (unsigned long, bitmap_size
);
1789 memcpy (save_in_use_p (p
), p
->in_use_p
, bitmap_size
);
1792 /* Reset reset the number of free objects and clear the
1793 in-use bits. These will be adjusted by mark_obj. */
1794 p
->num_free_objects
= num_objects
;
1795 memset (p
->in_use_p
, 0, bitmap_size
);
1797 /* Make sure the one-past-the-end bit is always set. */
1798 p
->in_use_p
[num_objects
/ HOST_BITS_PER_LONG
]
1799 = ((unsigned long) 1 << (num_objects
% HOST_BITS_PER_LONG
));
1804 /* Free all empty pages. Partially empty pages need no attention
1805 because the `mark' bit doubles as an `unused' bit. */
1812 for (order
= 2; order
< NUM_ORDERS
; order
++)
1814 /* The last page-entry to consider, regardless of entries
1815 placed at the end of the list. */
1816 page_entry
* const last
= G
.page_tails
[order
];
1819 size_t live_objects
;
1820 page_entry
*p
, *previous
;
1830 page_entry
*next
= p
->next
;
1832 /* Loop until all entries have been examined. */
1835 num_objects
= OBJECTS_IN_PAGE (p
);
1837 /* Add all live objects on this page to the count of
1838 allocated memory. */
1839 live_objects
= num_objects
- p
->num_free_objects
;
1841 G
.allocated
+= OBJECT_SIZE (order
) * live_objects
;
1843 /* Only objects on pages in the topmost context should get
1845 if (p
->context_depth
< G
.context_depth
)
1848 /* Remove the page if it's empty. */
1849 else if (live_objects
== 0)
1851 /* If P was the first page in the list, then NEXT
1852 becomes the new first page in the list, otherwise
1853 splice P out of the forward pointers. */
1855 G
.pages
[order
] = next
;
1857 previous
->next
= next
;
1859 /* Splice P out of the back pointers too. */
1861 next
->prev
= previous
;
1863 /* Are we removing the last element? */
1864 if (p
== G
.page_tails
[order
])
1865 G
.page_tails
[order
] = previous
;
1870 /* If the page is full, move it to the end. */
1871 else if (p
->num_free_objects
== 0)
1873 /* Don't move it if it's already at the end. */
1874 if (p
!= G
.page_tails
[order
])
1876 /* Move p to the end of the list. */
1878 p
->prev
= G
.page_tails
[order
];
1879 G
.page_tails
[order
]->next
= p
;
1881 /* Update the tail pointer... */
1882 G
.page_tails
[order
] = p
;
1884 /* ... and the head pointer, if necessary. */
1886 G
.pages
[order
] = next
;
1888 previous
->next
= next
;
1890 /* And update the backpointer in NEXT if necessary. */
1892 next
->prev
= previous
;
1898 /* If we've fallen through to here, it's a page in the
1899 topmost context that is neither full nor empty. Such a
1900 page must precede pages at lesser context depth in the
1901 list, so move it to the head. */
1902 else if (p
!= G
.pages
[order
])
1904 previous
->next
= p
->next
;
1906 /* Update the backchain in the next node if it exists. */
1908 p
->next
->prev
= previous
;
1910 /* Move P to the head of the list. */
1911 p
->next
= G
.pages
[order
];
1913 G
.pages
[order
]->prev
= p
;
1915 /* Update the head pointer. */
1918 /* Are we moving the last element? */
1919 if (G
.page_tails
[order
] == p
)
1920 G
.page_tails
[order
] = previous
;
1929 /* Now, restore the in_use_p vectors for any pages from contexts
1930 other than the current one. */
1931 for (p
= G
.pages
[order
]; p
; p
= p
->next
)
1932 if (p
->context_depth
!= G
.context_depth
)
1933 ggc_recalculate_in_use_p (p
);
1937 #ifdef ENABLE_GC_CHECKING
1938 /* Clobber all free objects. */
1945 for (order
= 2; order
< NUM_ORDERS
; order
++)
1947 size_t size
= OBJECT_SIZE (order
);
1950 for (p
= G
.pages
[order
]; p
!= NULL
; p
= p
->next
)
1955 if (p
->context_depth
!= G
.context_depth
)
1956 /* Since we don't do any collection for pages in pushed
1957 contexts, there's no need to do any poisoning. And
1958 besides, the IN_USE_P array isn't valid until we pop
1962 num_objects
= OBJECTS_IN_PAGE (p
);
1963 for (i
= 0; i
< num_objects
; i
++)
1966 word
= i
/ HOST_BITS_PER_LONG
;
1967 bit
= i
% HOST_BITS_PER_LONG
;
1968 if (((p
->in_use_p
[word
] >> bit
) & 1) == 0)
1970 char *object
= p
->page
+ i
* size
;
1972 /* Keep poison-by-write when we expect to use Valgrind,
1973 so the exact same memory semantics is kept, in case
1974 there are memory errors. We override this request
1976 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (object
,
1978 memset (object
, 0xa5, size
);
1980 /* Drop the handle to avoid handle leak. */
1981 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (object
, size
));
1988 #define poison_pages()
1991 #ifdef ENABLE_GC_ALWAYS_COLLECT
1992 /* Validate that the reportedly free objects actually are. */
1995 validate_free_objects (void)
1997 struct free_object
*f
, *next
, *still_free
= NULL
;
1999 for (f
= G
.free_object_list
; f
; f
= next
)
2001 page_entry
*pe
= lookup_page_table_entry (f
->object
);
2004 bit
= OFFSET_TO_BIT ((char *)f
->object
- pe
->page
, pe
->order
);
2005 word
= bit
/ HOST_BITS_PER_LONG
;
2006 bit
= bit
% HOST_BITS_PER_LONG
;
2009 /* Make certain it isn't visible from any root. Notice that we
2010 do this check before sweep_pages merges save_in_use_p. */
2011 gcc_assert (!(pe
->in_use_p
[word
] & (1UL << bit
)));
2013 /* If the object comes from an outer context, then retain the
2014 free_object entry, so that we can verify that the address
2015 isn't live on the stack in some outer context. */
2016 if (pe
->context_depth
!= G
.context_depth
)
2018 f
->next
= still_free
;
2025 G
.free_object_list
= still_free
;
2028 #define validate_free_objects()
2031 /* Top level mark-and-sweep routine. */
2036 /* Avoid frequent unnecessary work by skipping collection if the
2037 total allocations haven't expanded much since the last
2039 float allocated_last_gc
=
2040 MAX (G
.allocated_last_gc
, (size_t)PARAM_VALUE (GGC_MIN_HEAPSIZE
) * 1024);
2042 float min_expand
= allocated_last_gc
* PARAM_VALUE (GGC_MIN_EXPAND
) / 100;
2044 if (G
.allocated
< allocated_last_gc
+ min_expand
&& !ggc_force_collect
)
2047 timevar_push (TV_GC
);
2049 fprintf (stderr
, " {GC %luk -> ", (unsigned long) G
.allocated
/ 1024);
2050 if (GGC_DEBUG_LEVEL
>= 2)
2051 fprintf (G
.debug_file
, "BEGIN COLLECTING\n");
2053 /* Zero the total allocated bytes. This will be recalculated in the
2057 /* Release the pages we freed the last time we collected, but didn't
2058 reuse in the interim. */
2061 /* Indicate that we've seen collections at this context depth. */
2062 G
.context_depth_collections
= ((unsigned long)1 << (G
.context_depth
+ 1)) - 1;
2064 invoke_plugin_callbacks (PLUGIN_GGC_START
, NULL
);
2069 if (GATHER_STATISTICS
)
2070 ggc_prune_overhead_list ();
2073 validate_free_objects ();
2076 G
.allocated_last_gc
= G
.allocated
;
2078 invoke_plugin_callbacks (PLUGIN_GGC_END
, NULL
);
2080 timevar_pop (TV_GC
);
2083 fprintf (stderr
, "%luk}", (unsigned long) G
.allocated
/ 1024);
2084 if (GGC_DEBUG_LEVEL
>= 2)
2085 fprintf (G
.debug_file
, "END COLLECTING\n");
2088 /* Print allocation statistics. */
2089 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
2091 : ((x) < 1024*1024*10 \
2093 : (x) / (1024*1024))))
2094 #define STAT_LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
2097 ggc_print_statistics (void)
2099 struct ggc_statistics stats
;
2101 size_t total_overhead
= 0;
2103 /* Clear the statistics. */
2104 memset (&stats
, 0, sizeof (stats
));
2106 /* Make sure collection will really occur. */
2107 G
.allocated_last_gc
= 0;
2109 /* Collect and print the statistics common across collectors. */
2110 ggc_print_common_statistics (stderr
, &stats
);
2112 /* Release free pages so that we will not count the bytes allocated
2113 there as part of the total allocated memory. */
2116 /* Collect some information about the various sizes of
2119 "Memory still allocated at the end of the compilation process\n");
2120 fprintf (stderr
, "%-5s %10s %10s %10s\n",
2121 "Size", "Allocated", "Used", "Overhead");
2122 for (i
= 0; i
< NUM_ORDERS
; ++i
)
2129 /* Skip empty entries. */
2133 overhead
= allocated
= in_use
= 0;
2135 /* Figure out the total number of bytes allocated for objects of
2136 this size, and how many of them are actually in use. Also figure
2137 out how much memory the page table is using. */
2138 for (p
= G
.pages
[i
]; p
; p
= p
->next
)
2140 allocated
+= p
->bytes
;
2142 (OBJECTS_IN_PAGE (p
) - p
->num_free_objects
) * OBJECT_SIZE (i
);
2144 overhead
+= (sizeof (page_entry
) - sizeof (long)
2145 + BITMAP_SIZE (OBJECTS_IN_PAGE (p
) + 1));
2147 fprintf (stderr
, "%-5lu %10lu%c %10lu%c %10lu%c\n",
2148 (unsigned long) OBJECT_SIZE (i
),
2149 SCALE (allocated
), STAT_LABEL (allocated
),
2150 SCALE (in_use
), STAT_LABEL (in_use
),
2151 SCALE (overhead
), STAT_LABEL (overhead
));
2152 total_overhead
+= overhead
;
2154 fprintf (stderr
, "%-5s %10lu%c %10lu%c %10lu%c\n", "Total",
2155 SCALE (G
.bytes_mapped
), STAT_LABEL (G
.bytes_mapped
),
2156 SCALE (G
.allocated
), STAT_LABEL(G
.allocated
),
2157 SCALE (total_overhead
), STAT_LABEL (total_overhead
));
2159 if (GATHER_STATISTICS
)
2161 fprintf (stderr
, "\nTotal allocations and overheads during the compilation process\n");
2163 fprintf (stderr
, "Total Overhead: %10lld\n",
2164 G
.stats
.total_overhead
);
2165 fprintf (stderr
, "Total Allocated: %10lld\n",
2166 G
.stats
.total_allocated
);
2168 fprintf (stderr
, "Total Overhead under 32B: %10lld\n",
2169 G
.stats
.total_overhead_under32
);
2170 fprintf (stderr
, "Total Allocated under 32B: %10lld\n",
2171 G
.stats
.total_allocated_under32
);
2172 fprintf (stderr
, "Total Overhead under 64B: %10lld\n",
2173 G
.stats
.total_overhead_under64
);
2174 fprintf (stderr
, "Total Allocated under 64B: %10lld\n",
2175 G
.stats
.total_allocated_under64
);
2176 fprintf (stderr
, "Total Overhead under 128B: %10lld\n",
2177 G
.stats
.total_overhead_under128
);
2178 fprintf (stderr
, "Total Allocated under 128B: %10lld\n",
2179 G
.stats
.total_allocated_under128
);
2181 for (i
= 0; i
< NUM_ORDERS
; i
++)
2182 if (G
.stats
.total_allocated_per_order
[i
])
2184 fprintf (stderr
, "Total Overhead page size %7lu: %10lld\n",
2185 (unsigned long) OBJECT_SIZE (i
),
2186 G
.stats
.total_overhead_per_order
[i
]);
2187 fprintf (stderr
, "Total Allocated page size %7lu: %10lld\n",
2188 (unsigned long) OBJECT_SIZE (i
),
2189 G
.stats
.total_allocated_per_order
[i
]);
2194 struct ggc_pch_ondisk
2196 unsigned totals
[NUM_ORDERS
];
2201 struct ggc_pch_ondisk d
;
2202 uintptr_t base
[NUM_ORDERS
];
2203 size_t written
[NUM_ORDERS
];
2206 struct ggc_pch_data
*
2209 return XCNEW (struct ggc_pch_data
);
2213 ggc_pch_count_object (struct ggc_pch_data
*d
, void *x ATTRIBUTE_UNUSED
,
2214 size_t size
, bool is_string ATTRIBUTE_UNUSED
,
2215 enum gt_types_enum type ATTRIBUTE_UNUSED
)
2219 if (size
< NUM_SIZE_LOOKUP
)
2220 order
= size_lookup
[size
];
2224 while (size
> OBJECT_SIZE (order
))
2228 d
->d
.totals
[order
]++;
2232 ggc_pch_total_size (struct ggc_pch_data
*d
)
2237 for (i
= 0; i
< NUM_ORDERS
; i
++)
2238 a
+= PAGE_ALIGN (d
->d
.totals
[i
] * OBJECT_SIZE (i
));
2243 ggc_pch_this_base (struct ggc_pch_data
*d
, void *base
)
2245 uintptr_t a
= (uintptr_t) base
;
2248 for (i
= 0; i
< NUM_ORDERS
; i
++)
2251 a
+= PAGE_ALIGN (d
->d
.totals
[i
] * OBJECT_SIZE (i
));
2257 ggc_pch_alloc_object (struct ggc_pch_data
*d
, void *x ATTRIBUTE_UNUSED
,
2258 size_t size
, bool is_string ATTRIBUTE_UNUSED
,
2259 enum gt_types_enum type ATTRIBUTE_UNUSED
)
2264 if (size
< NUM_SIZE_LOOKUP
)
2265 order
= size_lookup
[size
];
2269 while (size
> OBJECT_SIZE (order
))
2273 result
= (char *) d
->base
[order
];
2274 d
->base
[order
] += OBJECT_SIZE (order
);
2279 ggc_pch_prepare_write (struct ggc_pch_data
*d ATTRIBUTE_UNUSED
,
2280 FILE *f ATTRIBUTE_UNUSED
)
2282 /* Nothing to do. */
2286 ggc_pch_write_object (struct ggc_pch_data
*d ATTRIBUTE_UNUSED
,
2287 FILE *f
, void *x
, void *newx ATTRIBUTE_UNUSED
,
2288 size_t size
, bool is_string ATTRIBUTE_UNUSED
)
2291 static const char emptyBytes
[256] = { 0 };
2293 if (size
< NUM_SIZE_LOOKUP
)
2294 order
= size_lookup
[size
];
2298 while (size
> OBJECT_SIZE (order
))
2302 if (fwrite (x
, size
, 1, f
) != 1)
2303 fatal_error ("can%'t write PCH file: %m");
2305 /* If SIZE is not the same as OBJECT_SIZE(order), then we need to pad the
2306 object out to OBJECT_SIZE(order). This happens for strings. */
2308 if (size
!= OBJECT_SIZE (order
))
2310 unsigned padding
= OBJECT_SIZE(order
) - size
;
2312 /* To speed small writes, we use a nulled-out array that's larger
2313 than most padding requests as the source for our null bytes. This
2314 permits us to do the padding with fwrite() rather than fseek(), and
2315 limits the chance the OS may try to flush any outstanding writes. */
2316 if (padding
<= sizeof(emptyBytes
))
2318 if (fwrite (emptyBytes
, 1, padding
, f
) != padding
)
2319 fatal_error ("can%'t write PCH file");
2323 /* Larger than our buffer? Just default to fseek. */
2324 if (fseek (f
, padding
, SEEK_CUR
) != 0)
2325 fatal_error ("can%'t write PCH file");
2329 d
->written
[order
]++;
2330 if (d
->written
[order
] == d
->d
.totals
[order
]
2331 && fseek (f
, ROUND_UP_VALUE (d
->d
.totals
[order
] * OBJECT_SIZE (order
),
2334 fatal_error ("can%'t write PCH file: %m");
2338 ggc_pch_finish (struct ggc_pch_data
*d
, FILE *f
)
2340 if (fwrite (&d
->d
, sizeof (d
->d
), 1, f
) != 1)
2341 fatal_error ("can%'t write PCH file: %m");
2345 /* Move the PCH PTE entries just added to the end of by_depth, to the
2349 move_ptes_to_front (int count_old_page_tables
, int count_new_page_tables
)
2353 /* First, we swap the new entries to the front of the varrays. */
2354 page_entry
**new_by_depth
;
2355 unsigned long **new_save_in_use
;
2357 new_by_depth
= XNEWVEC (page_entry
*, G
.by_depth_max
);
2358 new_save_in_use
= XNEWVEC (unsigned long *, G
.by_depth_max
);
2360 memcpy (&new_by_depth
[0],
2361 &G
.by_depth
[count_old_page_tables
],
2362 count_new_page_tables
* sizeof (void *));
2363 memcpy (&new_by_depth
[count_new_page_tables
],
2365 count_old_page_tables
* sizeof (void *));
2366 memcpy (&new_save_in_use
[0],
2367 &G
.save_in_use
[count_old_page_tables
],
2368 count_new_page_tables
* sizeof (void *));
2369 memcpy (&new_save_in_use
[count_new_page_tables
],
2371 count_old_page_tables
* sizeof (void *));
2374 free (G
.save_in_use
);
2376 G
.by_depth
= new_by_depth
;
2377 G
.save_in_use
= new_save_in_use
;
2379 /* Now update all the index_by_depth fields. */
2380 for (i
= G
.by_depth_in_use
; i
> 0; --i
)
2382 page_entry
*p
= G
.by_depth
[i
-1];
2383 p
->index_by_depth
= i
-1;
2386 /* And last, we update the depth pointers in G.depth. The first
2387 entry is already 0, and context 0 entries always start at index
2388 0, so there is nothing to update in the first slot. We need a
2389 second slot, only if we have old ptes, and if we do, they start
2390 at index count_new_page_tables. */
2391 if (count_old_page_tables
)
2392 push_depth (count_new_page_tables
);
2396 ggc_pch_read (FILE *f
, void *addr
)
2398 struct ggc_pch_ondisk d
;
2400 char *offs
= (char *) addr
;
2401 unsigned long count_old_page_tables
;
2402 unsigned long count_new_page_tables
;
2404 count_old_page_tables
= G
.by_depth_in_use
;
2406 /* We've just read in a PCH file. So, every object that used to be
2407 allocated is now free. */
2409 #ifdef ENABLE_GC_CHECKING
2412 /* Since we free all the allocated objects, the free list becomes
2413 useless. Validate it now, which will also clear it. */
2414 validate_free_objects();
2416 /* No object read from a PCH file should ever be freed. So, set the
2417 context depth to 1, and set the depth of all the currently-allocated
2418 pages to be 1 too. PCH pages will have depth 0. */
2419 gcc_assert (!G
.context_depth
);
2420 G
.context_depth
= 1;
2421 for (i
= 0; i
< NUM_ORDERS
; i
++)
2424 for (p
= G
.pages
[i
]; p
!= NULL
; p
= p
->next
)
2425 p
->context_depth
= G
.context_depth
;
2428 /* Allocate the appropriate page-table entries for the pages read from
2430 if (fread (&d
, sizeof (d
), 1, f
) != 1)
2431 fatal_error ("can%'t read PCH file: %m");
2433 for (i
= 0; i
< NUM_ORDERS
; i
++)
2435 struct page_entry
*entry
;
2441 if (d
.totals
[i
] == 0)
2444 bytes
= PAGE_ALIGN (d
.totals
[i
] * OBJECT_SIZE (i
));
2445 num_objs
= bytes
/ OBJECT_SIZE (i
);
2446 entry
= XCNEWVAR (struct page_entry
, (sizeof (struct page_entry
)
2448 + BITMAP_SIZE (num_objs
+ 1)));
2449 entry
->bytes
= bytes
;
2451 entry
->context_depth
= 0;
2453 entry
->num_free_objects
= 0;
2457 j
+ HOST_BITS_PER_LONG
<= num_objs
+ 1;
2458 j
+= HOST_BITS_PER_LONG
)
2459 entry
->in_use_p
[j
/ HOST_BITS_PER_LONG
] = -1;
2460 for (; j
< num_objs
+ 1; j
++)
2461 entry
->in_use_p
[j
/ HOST_BITS_PER_LONG
]
2462 |= 1L << (j
% HOST_BITS_PER_LONG
);
2464 for (pte
= entry
->page
;
2465 pte
< entry
->page
+ entry
->bytes
;
2467 set_page_table_entry (pte
, entry
);
2469 if (G
.page_tails
[i
] != NULL
)
2470 G
.page_tails
[i
]->next
= entry
;
2473 G
.page_tails
[i
] = entry
;
2475 /* We start off by just adding all the new information to the
2476 end of the varrays, later, we will move the new information
2477 to the front of the varrays, as the PCH page tables are at
2479 push_by_depth (entry
, 0);
2482 /* Now, we update the various data structures that speed page table
2484 count_new_page_tables
= G
.by_depth_in_use
- count_old_page_tables
;
2486 move_ptes_to_front (count_old_page_tables
, count_new_page_tables
);
2488 /* Update the statistics. */
2489 G
.allocated
= G
.allocated_last_gc
= offs
- (char *)addr
;
2497 struct alloc_zone rtl_zone
;
2498 struct alloc_zone tree_zone
;
2499 struct alloc_zone tree_id_zone
;