boolean enable_page_protection = 1;
/* the minimum size (in bytes) for a large object*/
+#if (GENCGC_ALLOC_GRANULARITY >= PAGE_BYTES) && (GENCGC_ALLOC_GRANULARITY >= GENCGC_CARD_BYTES)
long large_object_size = 4 * GENCGC_ALLOC_GRANULARITY;
+#elif (GENCGC_CARD_BYTES >= PAGE_BYTES) && (GENCGC_CARD_BYTES >= GENCGC_ALLOC_GRANULARITY)
+long large_object_size = 4 * GENCGC_CARD_BYTES;
+#else
+long large_object_size = 4 * PAGE_BYTES;
+#endif
\f
/*
extern unsigned long gencgc_release_granularity;
unsigned long gencgc_release_granularity = GENCGC_RELEASE_GRANULARITY;
+extern unsigned long gencgc_alloc_granularity;
+unsigned long gencgc_alloc_granularity = GENCGC_ALLOC_GRANULARITY;
+
\f
/*
* miscellaneous heap functions
}
+static void
+zero_and_mark_pages(page_index_t start, page_index_t end) {
+ page_index_t i;
+
+ zero_pages(start, end);
+ for (i = start; i <= end; i++)
+ page_table[i].need_to_zero = 0;
+}
+
/* Zero the pages from START to END (inclusive), except for those
* pages that are known to already zeroed. Mark all pages in the
* ranges as non-zeroed.
{
page_index_t first_page, last_page;
page_index_t restart_page = *restart_page_ptr;
+ long nbytes_goal = nbytes;
long bytes_found = 0;
long most_bytes_found = 0;
+ page_index_t most_bytes_found_from, most_bytes_found_to;
+ int small_object = nbytes < GENCGC_CARD_BYTES;
/* FIXME: assert(free_pages_lock is held); */
+ if (nbytes_goal < gencgc_alloc_granularity)
+ nbytes_goal = gencgc_alloc_granularity;
+
/* Toggled by gc_and_save for heap compaction, normally -1. */
if (gencgc_alloc_start_page != -1) {
restart_page = gencgc_alloc_start_page;
}
gc_assert(nbytes>=0);
- if (((unsigned long)nbytes)>=GENCGC_CARD_BYTES) {
- /* Search for a contiguous free space of at least nbytes,
- * aligned on a page boundary. The page-alignment is strictly
- * speaking needed only for objects at least large_object_size
- * bytes in size. */
- do {
- first_page = restart_page;
- while ((first_page < page_table_pages) &&
- page_allocated_p(first_page))
+ /* Search for a page with at least nbytes of space. We prefer
+ * not to split small objects on multiple pages, to reduce the
+ * number of contiguous allocation regions spaning multiple
+ * pages: this helps avoid excessive conservativism.
+ *
+ * For other objects, we guarantee that they start on their own
+ * page boundary.
+ */
+ first_page = restart_page;
+ while (first_page < page_table_pages) {
+ bytes_found = 0;
+ if (page_free_p(first_page)) {
+ gc_assert(0 == page_table[first_page].bytes_used);
+ bytes_found = GENCGC_CARD_BYTES;
+ } else if (small_object &&
+ (page_table[first_page].allocated == page_type_flag) &&
+ (page_table[first_page].large_object == 0) &&
+ (page_table[first_page].gen == gc_alloc_generation) &&
+ (page_table[first_page].write_protected == 0) &&
+ (page_table[first_page].dont_move == 0)) {
+ bytes_found = GENCGC_CARD_BYTES - page_table[first_page].bytes_used;
+ if (bytes_found < nbytes) {
+ if (bytes_found > most_bytes_found)
+ most_bytes_found = bytes_found;
first_page++;
-
- last_page = first_page;
- bytes_found = GENCGC_CARD_BYTES;
- while ((bytes_found < nbytes) &&
- (last_page < (page_table_pages-1)) &&
- page_free_p(last_page+1)) {
- last_page++;
- bytes_found += GENCGC_CARD_BYTES;
- gc_assert(0 == page_table[last_page].bytes_used);
- gc_assert(0 == page_table[last_page].write_protected);
+ continue;
}
- if (bytes_found > most_bytes_found)
- most_bytes_found = bytes_found;
- restart_page = last_page + 1;
- } while ((restart_page < page_table_pages) && (bytes_found < nbytes));
-
- } else {
- /* Search for a page with at least nbytes of space. We prefer
- * not to split small objects on multiple pages, to reduce the
- * number of contiguous allocation regions spaning multiple
- * pages: this helps avoid excessive conservativism. */
- first_page = restart_page;
- while (first_page < page_table_pages) {
- if (page_free_p(first_page))
- {
- gc_assert(0 == page_table[first_page].bytes_used);
- bytes_found = GENCGC_CARD_BYTES;
- break;
- }
- else if ((page_table[first_page].allocated == page_type_flag) &&
- (page_table[first_page].large_object == 0) &&
- (page_table[first_page].gen == gc_alloc_generation) &&
- (page_table[first_page].write_protected == 0) &&
- (page_table[first_page].dont_move == 0))
- {
- bytes_found = GENCGC_CARD_BYTES
- - page_table[first_page].bytes_used;
- if (bytes_found > most_bytes_found)
- most_bytes_found = bytes_found;
- if (bytes_found >= nbytes)
- break;
- }
+ } else {
first_page++;
+ continue;
}
- last_page = first_page;
- restart_page = first_page + 1;
+
+ gc_assert(page_table[first_page].write_protected == 0);
+ for (last_page = first_page+1;
+ ((last_page < page_table_pages) &&
+ page_free_p(last_page) &&
+ (bytes_found < nbytes_goal));
+ last_page++) {
+ bytes_found += GENCGC_CARD_BYTES;
+ gc_assert(0 == page_table[last_page].bytes_used);
+ gc_assert(0 == page_table[last_page].write_protected);
+ }
+
+ if (bytes_found > most_bytes_found) {
+ most_bytes_found = bytes_found;
+ most_bytes_found_from = first_page;
+ most_bytes_found_to = last_page;
+ }
+ if (bytes_found >= nbytes_goal)
+ break;
+
+ first_page = last_page;
}
+ bytes_found = most_bytes_found;
+ restart_page = first_page + 1;
+
/* Check for a failure */
if (bytes_found < nbytes) {
gc_assert(restart_page >= page_table_pages);
gc_heap_exhausted_error_or_lose(most_bytes_found, nbytes);
}
- gc_assert(page_table[first_page].write_protected == 0);
-
- *restart_page_ptr = first_page;
- return last_page;
+ *restart_page_ptr = most_bytes_found_from;
+ return most_bytes_found_to-1;
}
/* Allocate bytes. All the rest of the special-purpose allocation
}
static void
-remap_page_range (page_index_t from, page_index_t to, int forcibly)
+remap_page_range (page_index_t from, page_index_t to)
{
/* There's a mysterious Solaris/x86 problem with using mmap
* tricks for memory zeroing. See sbcl-devel thread
* "Re: patch: standalone executable redux".
- *
- * Since pages don't have to be zeroed ahead of time, only do
- * so when called from purify.
*/
#if defined(LISP_FEATURE_SUNOS)
- if (forcibly)
- zero_pages(from, to);
+ zero_and_mark_pages(from, to);
#else
- page_index_t aligned_from, aligned_end, end = to+1;
-
- const page_index_t
+ const page_index_t
release_granularity = gencgc_release_granularity/GENCGC_CARD_BYTES,
release_mask = release_granularity-1,
end = to+1,
if (aligned_from < aligned_end) {
zero_pages_with_mmap(aligned_from, aligned_end-1);
- if (forcibly) {
- if (aligned_from != from)
- zero_pages(from, aligned_from-1);
- if (aligned_end != end)
- zero_pages(aligned_end, end-1);
- }
- } else if (forcibly)
- zero_pages(from, to);
+ if (aligned_from != from)
+ zero_and_mark_pages(from, aligned_from-1);
+ if (aligned_end != end)
+ zero_and_mark_pages(aligned_end, end-1);
+ } else {
+ zero_and_mark_pages(from, to);
+ }
#endif
}
static void
remap_free_pages (page_index_t from, page_index_t to, int forcibly)
{
- page_index_t first_page, last_page,
- first_aligned_page, last_aligned_page;
+ page_index_t first_page, last_page;
if (forcibly)
- return remap_page_range(from, to, 1);
+ return remap_page_range(from, to);
- /* See comment above about mysterious failures on Solaris/x86.
- */
-#if !defined(LISP_FEATURE_SUNOS)
for (first_page = from; first_page <= to; first_page++) {
if (page_allocated_p(first_page) ||
(page_table[first_page].need_to_zero == 0))
(page_table[last_page].need_to_zero == 1))
last_page++;
- remap_page_range(first_page, last_page-1, 0);
+ remap_page_range(first_page, last_page-1);
first_page = last_page;
}
-#endif
}
generation_index_t small_generation_limit = 1;
projects / sbcl.git / blobdiff