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authorAndy Whitcroft <apw@shadowen.org>2008-11-06 12:53:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-11-06 15:41:18 -0800
commit18229df5b613ed0732a766fc37850de2e7988e43 (patch)
treeab235f27a5a9d93b8f94773252a1d8f660b9fad1 /mm/page_alloc.c
parent69d177c2fc702d402b17fdca2190d5a7e3ca55c5 (diff)
hugetlb: pull gigantic page initialisation out of the default path
As we can determine exactly when a gigantic page is in use we can optimise the common regular page cases by pulling out gigantic page initialisation into its own function. As gigantic pages are never released to buddy we do not need a destructor. This effectivly reverts the previous change to the main buddy allocator. It also adds a paranoid check to ensure we never release gigantic pages from hugetlbfs to the main buddy. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@kernel.org> [2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d0a240fbb8bf..54069e64e3a8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -263,24 +263,39 @@ void prep_compound_page(struct page *page, unsigned long order)
{
int i;
int nr_pages = 1 << order;
+
+ set_compound_page_dtor(page, free_compound_page);
+ set_compound_order(page, order);
+ __SetPageHead(page);
+ for (i = 1; i < nr_pages; i++) {
+ struct page *p = page + i;
+
+ __SetPageTail(p);
+ p->first_page = page;
+ }
+}
+
+#ifdef CONFIG_HUGETLBFS
+void prep_compound_gigantic_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
struct page *p = page + 1;
set_compound_page_dtor(page, free_compound_page);
set_compound_order(page, order);
__SetPageHead(page);
- for (i = 1; i < nr_pages; i++, p++) {
- if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0))
- p = pfn_to_page(page_to_pfn(page) + i);
+ for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
__SetPageTail(p);
p->first_page = page;
}
}
+#endif
static void destroy_compound_page(struct page *page, unsigned long order)
{
int i;
int nr_pages = 1 << order;
- struct page *p = page + 1;
if (unlikely(compound_order(page) != order))
bad_page(page);
@@ -288,9 +303,8 @@ static void destroy_compound_page(struct page *page, unsigned long order)
if (unlikely(!PageHead(page)))
bad_page(page);
__ClearPageHead(page);
- for (i = 1; i < nr_pages; i++, p++) {
- if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0))
- p = pfn_to_page(page_to_pfn(page) + i);
+ for (i = 1; i < nr_pages; i++) {
+ struct page *p = page + i;
if (unlikely(!PageTail(p) |
(p->first_page != page)))