/* "Bag-of-pages" garbage collector for the GNU compiler.
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009,
- 2010 Free Software Foundation, Inc.
+ 2010, 2011 Free Software Foundation, Inc.
This file is part of GCC.
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
-#include "toplev.h" /* exact_log2 */
#include "diagnostic-core.h"
#include "flags.h"
#include "ggc.h"
file open. Prefer either to valloc. */
#ifdef HAVE_MMAP_ANON
# undef HAVE_MMAP_DEV_ZERO
-
-# include <sys/mman.h>
-# ifndef MAP_FAILED
-# define MAP_FAILED -1
-# endif
-# if !defined (MAP_ANONYMOUS) && defined (MAP_ANON)
-# define MAP_ANONYMOUS MAP_ANON
-# endif
# define USING_MMAP
-
#endif
#ifdef HAVE_MMAP_DEV_ZERO
-
-# include <sys/mman.h>
-# ifndef MAP_FAILED
-# define MAP_FAILED -1
-# endif
# define USING_MMAP
-
#endif
#ifndef USING_MMAP
#define USING_MALLOC_PAGE_GROUPS
#endif
+#if defined(HAVE_MADVISE) && HAVE_DECL_MADVISE && defined(MADV_DONTNEED) \
+ && defined(USING_MMAP)
+# define USING_MADVISE
+#endif
+
/* Strategy:
This garbage-collecting allocator allocates objects on one of a set
sizeof (struct tree_field_decl),
sizeof (struct tree_parm_decl),
sizeof (struct tree_var_decl),
- sizeof (struct tree_type),
+ sizeof (struct tree_type_non_common),
sizeof (struct function),
sizeof (struct basic_block_def),
sizeof (struct cgraph_node),
#define ROUND_UP(x, f) (CEIL (x, f) * (f))
+/* Round X to next multiple of the page size */
+
+#define PAGE_ALIGN(x) (((x) + G.pagesize - 1) & ~(G.pagesize - 1))
+
/* The Ith entry is the number of objects on a page or order I. */
static unsigned objects_per_page_table[NUM_ORDERS];
/* The lg of size of objects allocated from this page. */
unsigned char order;
+ /* Discarded page? */
+ bool discarded;
+
/* A bit vector indicating whether or not objects are in use. The
Nth bit is one if the Nth object on this page is allocated. This
array is dynamically sized. */
can override this by defining GGC_QUIRE_SIZE explicitly. */
#ifndef GGC_QUIRE_SIZE
# ifdef USING_MMAP
-# define GGC_QUIRE_SIZE 256
+# define GGC_QUIRE_SIZE 512 /* 2MB for 4K pages */
# else
# define GGC_QUIRE_SIZE 16
# endif
static page_entry *lookup_page_table_entry (const void *);
static void set_page_table_entry (void *, page_entry *);
#ifdef USING_MMAP
-static char *alloc_anon (char *, size_t);
+static char *alloc_anon (char *, size_t, bool check);
#endif
#ifdef USING_MALLOC_PAGE_GROUPS
static size_t page_group_index (char *, char *);
compile error unless exactly one of the HAVE_* is defined. */
static inline char *
-alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size)
+alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, bool check)
{
#ifdef HAVE_MMAP_ANON
char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE,
if (page == (char *) MAP_FAILED)
{
+ if (!check)
+ return NULL;
perror ("virtual memory exhausted");
exit (FATAL_EXIT_CODE);
}
entry_size = num_objects * OBJECT_SIZE (order);
if (entry_size < G.pagesize)
entry_size = G.pagesize;
+ entry_size = PAGE_ALIGN (entry_size);
entry = NULL;
page = NULL;
if (p != NULL)
{
+ if (p->discarded)
+ G.bytes_mapped += p->bytes;
+ p->discarded = false;
+
/* Recycle the allocated memory from this page ... */
*pp = p->next;
page = p->page;
extras on the freelist. (Can only do this optimization with
mmap for backing store.) */
struct page_entry *e, *f = G.free_pages;
- int i;
+ int i, entries = GGC_QUIRE_SIZE;
- page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE);
+ page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE, false);
+ if (page == NULL)
+ {
+ page = alloc_anon(NULL, G.pagesize, true);
+ entries = 1;
+ }
/* This loop counts down so that the chain will be in ascending
memory order. */
- for (i = GGC_QUIRE_SIZE - 1; i >= 1; i--)
+ for (i = entries - 1; i >= 1; i--)
{
e = XCNEWVAR (struct page_entry, page_entry_size);
e->order = order;
G.free_pages = f;
}
else
- page = alloc_anon (NULL, entry_size);
+ page = alloc_anon (NULL, entry_size, true);
#endif
#ifdef USING_MALLOC_PAGE_GROUPS
else
static void
release_pages (void)
{
-#ifdef USING_MMAP
+#ifdef USING_MADVISE
+ page_entry *p, *start_p;
+ char *start;
+ size_t len;
+ size_t mapped_len;
+ page_entry *next, *prev, *newprev;
+ size_t free_unit = (GGC_QUIRE_SIZE/2) * G.pagesize;
+
+ /* First free larger continuous areas to the OS.
+ This allows other allocators to grab these areas if needed.
+ This is only done on larger chunks to avoid fragmentation.
+ This does not always work because the free_pages list is only
+ approximately sorted. */
+
+ p = G.free_pages;
+ prev = NULL;
+ while (p)
+ {
+ start = p->page;
+ start_p = p;
+ len = 0;
+ mapped_len = 0;
+ newprev = prev;
+ while (p && p->page == start + len)
+ {
+ len += p->bytes;
+ if (!p->discarded)
+ mapped_len += p->bytes;
+ newprev = p;
+ p = p->next;
+ }
+ if (len >= free_unit)
+ {
+ while (start_p != p)
+ {
+ next = start_p->next;
+ free (start_p);
+ start_p = next;
+ }
+ munmap (start, len);
+ if (prev)
+ prev->next = p;
+ else
+ G.free_pages = p;
+ G.bytes_mapped -= mapped_len;
+ continue;
+ }
+ prev = newprev;
+ }
+
+ /* Now give back the fragmented pages to the OS, but keep the address
+ space to reuse it next time. */
+
+ for (p = G.free_pages; p; )
+ {
+ if (p->discarded)
+ {
+ p = p->next;
+ continue;
+ }
+ start = p->page;
+ len = p->bytes;
+ start_p = p;
+ p = p->next;
+ while (p && p->page == start + len)
+ {
+ len += p->bytes;
+ p = p->next;
+ }
+ /* Give the page back to the kernel, but don't free the mapping.
+ This avoids fragmentation in the virtual memory map of the
+ process. Next time we can reuse it by just touching it. */
+ madvise (start, len, MADV_DONTNEED);
+ /* Don't count those pages as mapped to not touch the garbage collector
+ unnecessarily. */
+ G.bytes_mapped -= len;
+ while (start_p != p)
+ {
+ start_p->discarded = true;
+ start_p = start_p->next;
+ }
+ }
+#endif
+#if defined(USING_MMAP) && !defined(USING_MADVISE)
page_entry *p, *next;
char *start;
size_t len;
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
};
+/* For a given size of memory requested for allocation, return the
+ actual size that is going to be allocated, as well as the size
+ order. */
+
+static void
+ggc_round_alloc_size_1 (size_t requested_size,
+ size_t *size_order,
+ size_t *alloced_size)
+{
+ size_t order, object_size;
+
+ if (requested_size < NUM_SIZE_LOOKUP)
+ {
+ order = size_lookup[requested_size];
+ object_size = OBJECT_SIZE (order);
+ }
+ else
+ {
+ order = 10;
+ while (requested_size > (object_size = OBJECT_SIZE (order)))
+ order++;
+ }
+
+ if (size_order)
+ *size_order = order;
+ if (alloced_size)
+ *alloced_size = object_size;
+}
+
+/* For a given size of memory requested for allocation, return the
+ actual size that is going to be allocated. */
+
+size_t
+ggc_round_alloc_size (size_t requested_size)
+{
+ size_t size = 0;
+
+ ggc_round_alloc_size_1 (requested_size, NULL, &size);
+ return size;
+}
+
/* Typed allocation function. Does nothing special in this collector. */
void *
struct page_entry *entry;
void *result;
- if (size < NUM_SIZE_LOOKUP)
- {
- order = size_lookup[size];
- object_size = OBJECT_SIZE (order);
- }
- else
- {
- order = 10;
- while (size > (object_size = OBJECT_SIZE (order)))
- order++;
- }
+ ggc_round_alloc_size_1 (size, &order, &object_size);
/* If there are non-full pages for this size allocation, they are at
the head of the list. */
believe, is an unaligned page allocation, which would cause us to
hork badly if we tried to use it. */
{
- char *p = alloc_anon (NULL, G.pagesize);
+ char *p = alloc_anon (NULL, G.pagesize, true);
struct page_entry *e;
if ((size_t)p & (G.pagesize - 1))
{
/* How losing. Discard this one and try another. If we still
can't get something useful, give up. */
- p = alloc_anon (NULL, G.pagesize);
+ p = alloc_anon (NULL, G.pagesize, true);
gcc_assert (!((size_t)p & (G.pagesize - 1)));
}
{
fprintf (stderr, "\nTotal allocations and overheads during the compilation process\n");
- fprintf (stderr, "Total Overhead: %10lld\n",
+ fprintf (stderr, "Total Overhead: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_overhead);
- fprintf (stderr, "Total Allocated: %10lld\n",
+ fprintf (stderr, "Total Allocated: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_allocated);
- fprintf (stderr, "Total Overhead under 32B: %10lld\n",
+ fprintf (stderr, "Total Overhead under 32B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_overhead_under32);
- fprintf (stderr, "Total Allocated under 32B: %10lld\n",
+ fprintf (stderr, "Total Allocated under 32B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_allocated_under32);
- fprintf (stderr, "Total Overhead under 64B: %10lld\n",
+ fprintf (stderr, "Total Overhead under 64B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_overhead_under64);
- fprintf (stderr, "Total Allocated under 64B: %10lld\n",
+ fprintf (stderr, "Total Allocated under 64B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_allocated_under64);
- fprintf (stderr, "Total Overhead under 128B: %10lld\n",
+ fprintf (stderr, "Total Overhead under 128B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_overhead_under128);
- fprintf (stderr, "Total Allocated under 128B: %10lld\n",
+ fprintf (stderr, "Total Allocated under 128B: %10" HOST_LONG_LONG_FORMAT "d\n",
G.stats.total_allocated_under128);
for (i = 0; i < NUM_ORDERS; i++)
if (G.stats.total_allocated_per_order[i])
{
- fprintf (stderr, "Total Overhead page size %7lu: %10lld\n",
+ fprintf (stderr, "Total Overhead page size %7lu: %10" HOST_LONG_LONG_FORMAT "d\n",
(unsigned long) OBJECT_SIZE (i),
G.stats.total_overhead_per_order[i]);
- fprintf (stderr, "Total Allocated page size %7lu: %10lld\n",
+ fprintf (stderr, "Total Allocated page size %7lu: %10" HOST_LONG_LONG_FORMAT "d\n",
(unsigned long) OBJECT_SIZE (i),
G.stats.total_allocated_per_order[i]);
}
unsigned i;
for (i = 0; i < NUM_ORDERS; i++)
- a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i));
return a;
}
for (i = 0; i < NUM_ORDERS; i++)
{
d->base[i] = a;
- a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i));
}
}
if (d.totals[i] == 0)
continue;
- bytes = ROUND_UP (d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ bytes = PAGE_ALIGN (d.totals[i] * OBJECT_SIZE (i));
num_objs = bytes / OBJECT_SIZE (i);
entry = XCNEWVAR (struct page_entry, (sizeof (struct page_entry)
- sizeof (long)
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