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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
parent69d177c2fc702d402b17fdca2190d5a7e3ca55c5 (diff)
downloadop-kernel-dev-18229df5b613ed0732a766fc37850de2e7988e43.zip
op-kernel-dev-18229df5b613ed0732a766fc37850de2e7988e43.tar.gz
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>
-rw-r--r--mm/hugetlb.c12
-rw-r--r--mm/internal.h1
-rw-r--r--mm/page_alloc.c28
3 files changed, 33 insertions, 8 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e6afe52..d143ab6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -491,6 +491,8 @@ static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ VM_BUG_ON(h->order >= MAX_ORDER);
+
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
for (i = 0; i < pages_per_huge_page(h); i++) {
@@ -1005,6 +1007,14 @@ found:
return 1;
}
+static void prep_compound_huge_page(struct page *page, int order)
+{
+ if (unlikely(order > (MAX_ORDER - 1)))
+ prep_compound_gigantic_page(page, order);
+ else
+ prep_compound_page(page, order);
+}
+
/* Put bootmem huge pages into the standard lists after mem_map is up */
static void __init gather_bootmem_prealloc(void)
{
@@ -1015,7 +1025,7 @@ static void __init gather_bootmem_prealloc(void)
struct hstate *h = m->hstate;
__ClearPageReserved(page);
WARN_ON(page_count(page) != 1);
- prep_compound_page(page, h->order);
+ prep_compound_huge_page(page, h->order);
prep_new_huge_page(h, page, page_to_nid(page));
}
}
diff --git a/mm/internal.h b/mm/internal.h
index f482460..13333bc 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -17,6 +17,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
extern void prep_compound_page(struct page *page, unsigned long order);
+extern void prep_compound_gigantic_page(struct page *page, unsigned long order);
static inline void set_page_count(struct page *page, int v)
{
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d0a240f..54069e6 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)))
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