static void add_single_pages(struct page *base)
/* Effects: Adds pages at base to the single_pages list */
{
// fprintf(stderr, "## add_single_pages: base=%p, base->pagecount=%d\n",
// base, base->pagecount);
assert(base->pagecount > 0);
pageid n = base->pagecount;
struct page *prev = base->prev_address, *basenext = base->next_address,
*next;
single_page_count += n;
for (;;)
{
// split 'base' into single pages.
ASSERT_FREE(base);
VALGRIND_MAKE_WRITABLE(base, sizeof(struct page));
base->free = 0; /* Not free so that coalesce won't steal these back */
base->prev_address = prev;
// enforce the invariant that 'pagecount' is always correct: make sure
// we record that this page has size 1
base->pagecount = 1;
prev = base;
base->next = single_pages;
single_pages = base;
if (--n == 0)
break;
next = (struct page *)((char *)base + RPAGESIZE);
base->next_address = next;
base = next;
}
base->next_address = basenext;
basenext->prev_address = base;
}
void add_single_pages(struct page *base)
/* Effects: Adds pages at base to the single_pages list */
{
pageid n;
struct page *next;
unsigned long int index;
if (base == NULL)
return;
n = base->pagecount;
index = base->list_id;
single_pages[index].page_count += n;
for ( ; ; ) {
ASSERT_FREE(base);
base->free = 0; /* Not free so that coalesce
* won't steal these back */
base->next = single_pages[index].pages;
single_pages[index].pages = base;
if (--n == 0)
break;
next = (struct page*)( (char*)base + RPAGESIZE );
base = next;
}
}
struct page *alloc_single_page(struct page *next)
{
struct page *p;
if (single_pages) {
assert(single_page_count > 0);
} else {
scavenge_single_pages(PAGE_GROUP_SIZE);
}
ASSERT_FREE(single_pages);
p = single_pages;
single_pages = p->next;
p->next = next;
single_page_count--;
// fprintf(stderr, "## alloc_single_page: p=%p\n", p);
assert(p->pagecount > 0);
return p;
}
