[PATCH] Make page allocator aware of requests for zeroed memory

Thisintroduces __GFP_ZERO as an additional gfp_mask element to allow to
request zeroed pages from the page allocator:

 - Modifies the page allocator so that it zeroes memory if __GFP_ZERO is
   set

 - Replace all page zeroing after allocating pages by prior allocations with
   allocations using __GFP_ZERO

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

22 files changed, 58 insertions, 116 deletions

diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index 3ea81ca1c6d9..90752f6d8867 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -42,10 +42,9 @@ pgd_alloc(struct mm_struct *mm)
 {
 	pgd_t *ret, *init;
 
-	ret = (pgd_t *)__get_free_page(GFP_KERNEL);
+	ret = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 	init = pgd_offset(&init_mm, 0UL);
 	if (ret) {
-		clear_page(ret);
 #ifdef CONFIG_ALPHA_LARGE_VMALLOC
 		memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
 			(PTRS_PER_PGD - USER_PTRS_PER_PGD - 1)*sizeof(pgd_t));
@@ -63,9 +62,7 @@ pgd_alloc(struct mm_struct *mm)
 pte_t *
 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
-	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
+	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pte;
 }
 
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 83c201b0fd56..77ffaf855fd1 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -140,10 +140,7 @@ void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
 
 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
-	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
-	return pte;
+	return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 }
 
 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
@@ -151,12 +148,10 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 	struct page *pte;
 
 #ifdef CONFIG_HIGHPTE
-	pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT, 0);
+	pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
 #else
-	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 #endif
-	if (pte)
-		clear_highpage(pte);
 	return pte;
 }
 
diff --git a/arch/ppc/mm/pgtable.c b/arch/ppc/mm/pgtable.c
index 4adc48c695d6..bda12bd5786f 100644
--- a/arch/ppc/mm/pgtable.c
+++ b/arch/ppc/mm/pgtable.c
@@ -85,8 +85,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	pgd_t *ret;
 
-	if ((ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGDIR_ORDER)) != NULL)
-		clear_pages(ret, PGDIR_ORDER);
+	ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
 	return ret;
 }
 
@@ -102,7 +101,7 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 	extern void *early_get_page(void);
 
 	if (mem_init_done) {
-		pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+		pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 		if (pte) {
 			struct page *ptepage = virt_to_page(pte);
 			ptepage->mapping = (void *) mm;
@@ -110,8 +109,6 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 		}
 	} else
 		pte = (pte_t *)early_get_page();
-	if (pte)
-		clear_page(pte);
 	return pte;
 }
 
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index e85060445191..ebc49a45102a 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -1687,13 +1687,12 @@ void __init mem_init(void)
 	 * Set up the zero page, mark it reserved, so that page count
 	 * is not manipulated when freeing the page from user ptes.
 	 */
-	mem_map_zero = alloc_pages(GFP_KERNEL, 0);
+	mem_map_zero = alloc_pages(GFP_KERNEL|__GFP_ZERO, 0);
 	if (mem_map_zero == NULL) {
 		prom_printf("paging_init: Cannot alloc zero page.\n");
 		prom_halt();
 	}
 	SetPageReserved(mem_map_zero);
-	clear_page(page_address(mem_map_zero));
 
 	codepages = (((unsigned long) _etext) - ((unsigned long) _start));
 	codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index e907e0521564..4279161c8849 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -327,9 +327,7 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
 	pte_t *pte;
 
-	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
+	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pte;
 }
 
@@ -337,9 +335,7 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	struct page *pte;
    
-	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
-	if (pte)
-		clear_highpage(pte);
+	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 	return pte;
 }
 
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 03a9388049a4..aa4a3065b361 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -135,12 +135,10 @@ static struct packet_data *pkt_alloc_packet_data(void)
 		goto no_bio;
 
 	for (i = 0; i < PAGES_PER_PACKET; i++) {
-		pkt->pages[i] = alloc_page(GFP_KERNEL);
+		pkt->pages[i] = alloc_page(GFP_KERNEL|| __GFP_ZERO);
 		if (!pkt->pages[i])
 			goto no_page;
 	}
-	for (i = 0; i < PAGES_PER_PACKET; i++)
-		clear_page(page_address(pkt->pages[i]));
 
 	spin_lock_init(&pkt->lock);
 
diff --git a/include/asm-alpha/pgalloc.h b/include/asm-alpha/pgalloc.h
index b671bb3c20b4..308475642913 100644
--- a/include/asm-alpha/pgalloc.h
+++ b/include/asm-alpha/pgalloc.h
@@ -40,9 +40,7 @@ pgd_free(pgd_t *pgd)
 static inline pmd_t *
 pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
-	pmd_t *ret = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (ret)
-		clear_page(ret);
+	pmd_t *ret = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return ret;
 }
 
diff --git a/include/asm-arm/pgalloc.h b/include/asm-arm/pgalloc.h
index 23eb321f4af2..e814f8144f8b 100644
--- a/include/asm-arm/pgalloc.h
+++ b/include/asm-arm/pgalloc.h
@@ -50,9 +50,8 @@ pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
 {
 	pte_t *pte;
 
-	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	if (pte) {
-		clear_page(pte);
 		clean_dcache_area(pte, sizeof(pte_t) * PTRS_PER_PTE);
 		pte += PTRS_PER_PTE;
 	}
@@ -65,10 +64,9 @@ pte_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
 	struct page *pte;
 
-	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 	if (pte) {
 		void *page = page_address(pte);
-		clear_page(page);
 		clean_dcache_area(page, sizeof(pte_t) * PTRS_PER_PTE);
 	}
 
diff --git a/include/asm-cris/pgalloc.h b/include/asm-cris/pgalloc.h
index ca769e060298..7f313d563c28 100644
--- a/include/asm-cris/pgalloc.h
+++ b/include/asm-cris/pgalloc.h
@@ -24,18 +24,14 @@ extern inline void pgd_free (pgd_t *pgd)
 
 extern inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
-  	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
+  	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
  	return pte;
 }
 
 extern inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	struct page *pte;
-	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
-	if (pte)
-		clear_page(page_address(pte));
+	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 	return pte;
 }
 
diff --git a/include/asm-ia64/pgalloc.h b/include/asm-ia64/pgalloc.h
index 2bd68d4aa77c..fda0dba0b187 100644
--- a/include/asm-ia64/pgalloc.h
+++ b/include/asm-ia64/pgalloc.h
@@ -61,9 +61,7 @@ pgd_alloc (struct mm_struct *mm)
 	pgd_t *pgd = pgd_alloc_one_fast(mm);
 
 	if (unlikely(pgd == NULL)) {
-		pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
-		if (likely(pgd != NULL))
-			clear_page(pgd);
+		pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
 	}
 	return pgd;
 }
@@ -106,10 +104,8 @@ pmd_alloc_one_fast (struct mm_struct *mm, unsigned long addr)
 static inline pmd_t*
 pmd_alloc_one (struct mm_struct *mm, unsigned long addr)
 {
-	pmd_t *pmd = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+	pmd_t *pmd = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 
-	if (likely(pmd != NULL))
-		clear_page(pmd);
 	return pmd;
 }
 
@@ -140,20 +136,16 @@ pmd_populate_kernel (struct mm_struct *mm, pmd_t *pmd_entry, pte_t *pte)
 static inline struct page *
 pte_alloc_one (struct mm_struct *mm, unsigned long addr)
 {
-	struct page *pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+	struct page *pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 
-	if (likely(pte != NULL))
-		clear_page(page_address(pte));
 	return pte;
 }
 
 static inline pte_t *
 pte_alloc_one_kernel (struct mm_struct *mm, unsigned long addr)
 {
-	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 
-	if (likely(pte != NULL))
-		clear_page(pte);
 	return pte;
 }
 
diff --git a/include/asm-m32r/pgalloc.h b/include/asm-m32r/pgalloc.h
index 8d5a44485211..da6dd7bd7529 100644
--- a/include/asm-m32r/pgalloc.h
+++ b/include/asm-m32r/pgalloc.h
@@ -23,10 +23,7 @@ static __inline__ void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  */
 static __inline__ pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
-
-	if (pgd)
-		clear_page(pgd);
+	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
 
 	return pgd;
 }
@@ -39,10 +36,7 @@ static __inline__ void pgd_free(pgd_t *pgd)
 static __inline__ pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 	unsigned long address)
 {
-	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL);
-
-	if (pte)
-		clear_page(pte);
+	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
 
 	return pte;
 }
@@ -50,10 +44,8 @@ static __inline__ pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 static __inline__ struct page *pte_alloc_one(struct mm_struct *mm,
 	unsigned long address)
 {
-	struct page *pte = alloc_page(GFP_KERNEL);
+	struct page *pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
 
-	if (pte)
-		clear_page(page_address(pte));
 
 	return pte;
 }
diff --git a/include/asm-m68k/motorola_pgalloc.h b/include/asm-m68k/motorola_pgalloc.h
index dda9618adc07..5158412cd54d 100644
--- a/include/asm-m68k/motorola_pgalloc.h
+++ b/include/asm-m68k/motorola_pgalloc.h
@@ -12,9 +12,8 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long ad
 {
 	pte_t *pte;
 
-	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	if (pte) {
-		clear_page(pte);
 		__flush_page_to_ram(pte);
 		flush_tlb_kernel_page(pte);
 		nocache_page(pte);
@@ -31,7 +30,7 @@ static inline void pte_free_kernel(pte_t *pte)
 
 static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 {
-	struct page *page = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+	struct page *page = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 	pte_t *pte;
 
 	if(!page)
@@ -39,7 +38,6 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long add
 
 	pte = kmap(page);
 	if (pte) {
-		clear_page(pte);
 		__flush_page_to_ram(pte);
 		flush_tlb_kernel_page(pte);
 		nocache_page(pte);
diff --git a/include/asm-mips/pgalloc.h b/include/asm-mips/pgalloc.h
index 4f96427f89f4..2d63f5ba403f 100644
--- a/include/asm-mips/pgalloc.h
+++ b/include/asm-mips/pgalloc.h
@@ -56,9 +56,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 {
 	pte_t *pte;
 
-	pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_REPEAT, PTE_ORDER);
-	if (pte)
-		clear_page(pte);
+	pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, PTE_ORDER);
 
 	return pte;
 }
diff --git a/include/asm-parisc/pgalloc.h b/include/asm-parisc/pgalloc.h
index 53a6fec7df95..22b6ae6c45e0 100644
--- a/include/asm-parisc/pgalloc.h
+++ b/include/asm-parisc/pgalloc.h
@@ -120,18 +120,14 @@ pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
 static inline struct page *
 pte_alloc_one(struct mm_struct *mm, unsigned long address)
 {
-	struct page *page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
-	if (likely(page != NULL))
-		clear_page(page_address(page));
+	struct page *page = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return page;
 }
 
 static inline pte_t *
 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
 {
-	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (likely(pte != NULL))
-		clear_page(pte);
+	pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pte;
 }
 
diff --git a/include/asm-sh/pgalloc.h b/include/asm-sh/pgalloc.h
index 8a1b3597ff30..1a998085f961 100644
--- a/include/asm-sh/pgalloc.h
+++ b/include/asm-sh/pgalloc.h
@@ -44,9 +44,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 {
 	pte_t *pte;
 
-	pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
+	pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
 
 	return pte;
 }
@@ -56,9 +54,7 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm,
 {
 	struct page *pte;
 
-   	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
-	if (pte)
-		clear_page(page_address(pte));
+   	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 
 	return pte;
 }
diff --git a/include/asm-sh64/pgalloc.h b/include/asm-sh64/pgalloc.h
index 02723085d0d9..b843ec2478b1 100644
--- a/include/asm-sh64/pgalloc.h
+++ b/include/asm-sh64/pgalloc.h
@@ -112,9 +112,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 {
 	pte_t *pte;
 
-	pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
-	if (pte)
-		clear_page(pte);
+	pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT|__GFP_ZERO);
 
 	return pte;
 }
@@ -123,9 +121,7 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long add
 {
 	struct page *pte;
 
-	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
-	if (pte)
-		clear_page(page_address(pte));
+	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
 
 	return pte;
 }
@@ -150,9 +146,7 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long add
 static __inline__ pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pmd_t *pmd;
-	pmd = (pmd_t *) __get_free_page(GFP_KERNEL|__GFP_REPEAT);
-	if (pmd)
-		clear_page(pmd);
+	pmd = (pmd_t *) __get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pmd;
 }
 
diff --git a/include/asm-sparc64/pgalloc.h b/include/asm-sparc64/pgalloc.h
index fa5c704dedaf..6a365ffe30dc 100644
--- a/include/asm-sparc64/pgalloc.h
+++ b/include/asm-sparc64/pgalloc.h
@@ -73,10 +73,9 @@ static __inline__ pgd_t *get_pgd_fast(void)
 		struct page *page;
 
 		preempt_enable();
-		page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
+		page = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 		if (page) {
 			ret = (struct page *)page_address(page);
-			clear_page(ret);
 			page->lru.prev = (void *) 2UL;
 
 			preempt_disable();
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 600f83c80aad..823589766569 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -37,6 +37,7 @@ struct vm_area_struct;
 #define __GFP_NORETRY	0x1000	/* Do not retry.  Might fail */
 #define __GFP_NO_GROW	0x2000	/* Slab internal usage */
 #define __GFP_COMP	0x4000	/* Add compound page metadata */
+#define __GFP_ZERO	0x8000	/* Return zeroed page on success */
 
 #define __GFP_BITS_SHIFT 16	/* Room for 16 __GFP_FOO bits */
 #define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
@@ -52,6 +53,7 @@ struct vm_area_struct;
 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
 #define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS)
 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)
+#define GFP_HIGHZERO	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM | __GFP_ZERO)
 
 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
    platforms, used as appropriate on others */
diff --git a/kernel/profile.c b/kernel/profile.c
index ff62fa98328a..1bf1ec5fe56b 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -326,17 +326,15 @@ static int __devinit profile_cpu_callback(struct notifier_block *info,
 		node = cpu_to_node(cpu);
 		per_cpu(cpu_profile_flip, cpu) = 0;
 		if (!per_cpu(cpu_profile_hits, cpu)[1]) {
-			page = alloc_pages_node(node, GFP_KERNEL, 0);
+			page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
 			if (!page)
 				return NOTIFY_BAD;
-			clear_highpage(page);
 			per_cpu(cpu_profile_hits, cpu)[1] = page_address(page);
 		}
 		if (!per_cpu(cpu_profile_hits, cpu)[0]) {
-			page = alloc_pages_node(node, GFP_KERNEL, 0);
+			page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
 			if (!page)
 				goto out_free;
-			clear_highpage(page);
 			per_cpu(cpu_profile_hits, cpu)[0] = page_address(page);
 		}
 		break;
@@ -510,16 +508,14 @@ static int __init create_hash_tables(void)
 		int node = cpu_to_node(cpu);
 		struct page *page;
 
-		page = alloc_pages_node(node, GFP_KERNEL, 0);
+		page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
 		if (!page)
 			goto out_cleanup;
-		clear_highpage(page);
 		per_cpu(cpu_profile_hits, cpu)[1]
 				= (struct profile_hit *)page_address(page);
-		page = alloc_pages_node(node, GFP_KERNEL, 0);
+		page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
 		if (!page)
 			goto out_cleanup;
-		clear_highpage(page);
 		per_cpu(cpu_profile_hits, cpu)[0]
 				= (struct profile_hit *)page_address(page);
 	}
diff --git a/mm/memory.c b/mm/memory.c
index b0c61dac23e6..ad9407594ba5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1673,10 +1673,9 @@ do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
 		if (unlikely(anon_vma_prepare(vma)))
 			goto no_mem;
-		page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
+		page = alloc_page_vma(GFP_HIGHZERO, vma, addr);
 		if (!page)
 			goto no_mem;
-		clear_user_highpage(page, addr);
 
 		spin_lock(&mm->page_table_lock);
 		page_table = pte_offset_map(pmd, addr);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4fb4da2dd5e2..fd6f8014689b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -558,6 +558,13 @@ void fastcall free_cold_page(struct page *page)
  * we cheat by calling it from here, in the order > 0 path.  Saves a branch
  * or two.
  */
+static inline void prep_zero_page(struct page *page, int order)
+{
+	int i;
+
+	for(i = 0; i < (1 << order); i++)
+		clear_highpage(page + i);
+}
 
 static struct page *
 buffered_rmqueue(struct zone *zone, int order, int gfp_flags)
@@ -593,6 +600,10 @@ buffered_rmqueue(struct zone *zone, int order, int gfp_flags)
 		BUG_ON(bad_range(zone, page));
 		mod_page_state_zone(zone, pgalloc, 1 << order);
 		prep_new_page(page, order);
+
+		if (gfp_flags & __GFP_ZERO)
+			prep_zero_page(page, order);
+
 		if (order && (gfp_flags & __GFP_COMP))
 			prep_compound_page(page, order);
 	}
@@ -805,12 +816,9 @@ fastcall unsigned long get_zeroed_page(unsigned int gfp_mask)
 	 */
 	BUG_ON(gfp_mask & __GFP_HIGHMEM);
 
-	page = alloc_pages(gfp_mask, 0);
-	if (page) {
-		void *address = page_address(page);
-		clear_page(address);
-		return (unsigned long) address;
-	}
+	page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
+	if (page)
+		return (unsigned long) page_address(page);
 	return 0;
 }
 
diff --git a/mm/shmem.c b/mm/shmem.c
index e1ff7d74c249..2a97375d5ece 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -369,9 +369,8 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
 		}
 
 		spin_unlock(&info->lock);
-		page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
+		page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping) | __GFP_ZERO);
 		if (page) {
-			clear_highpage(page);
 			page->nr_swapped = 0;
 		}
 		spin_lock(&info->lock);
@@ -910,7 +909,7 @@ shmem_alloc_page(unsigned long gfp, struct shmem_inode_info *info,
 	pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
 	pvma.vm_pgoff = idx;
 	pvma.vm_end = PAGE_SIZE;
-	page = alloc_page_vma(gfp, &pvma, 0);
+	page = alloc_page_vma(gfp | __GFP_ZERO, &pvma, 0);
 	mpol_free(pvma.vm_policy);
 	return page;
 }
@@ -926,7 +925,7 @@ static inline struct page *
 shmem_alloc_page(unsigned long gfp,struct shmem_inode_info *info,
 				 unsigned long idx)
 {
-	return alloc_page(gfp);
+	return alloc_page(gfp | __GFP_ZERO);
 }
 #endif
 
@@ -1135,7 +1134,6 @@ repeat:
 
 		info->alloced++;
 		spin_unlock(&info->lock);
-		clear_highpage(filepage);
 		flush_dcache_page(filepage);
 		SetPageUptodate(filepage);
 	}