[PATCH] mm: ptd_alloc inline and out

It seems odd to me that, whereas pud_alloc and pmd_alloc test inline, only
calling out-of-line __pud_alloc __pmd_alloc if allocation needed,
pte_alloc_map and pte_alloc_kernel are entirely out-of-line.  Though it does
add a little to kernel size, change them to macros testing inline, calling
__pte_alloc or __pte_alloc_kernel to allocate out-of-line.  Mark none of them
as fastcalls, leave that to CONFIG_REGPARM or not.

It also seems more natural for the out-of-line functions to leave the offset
calculation and map to the inline, which has to do it anyway for the common
case.  At least mremap move wants __pte_alloc without _map.

Macros rather than inline functions, certainly to avoid the header file issues
which arise from CONFIG_HIGHPTE needing kmap_types.h, but also in case any
architectures I haven't built would have other such problems.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 22 insertions, 27 deletions

diff --git a/include/asm-generic/4level-fixup.h b/include/asm-generic/4level-fixup.h
index c20ec25..68c6fea 100644
--- a/include/asm-generic/4level-fixup.h
+++ b/include/asm-generic/4level-fixup.h
@@ -10,14 +10,9 @@
 
 #define pud_t				pgd_t
 
-#define pmd_alloc(mm, pud, address)			\
-({	pmd_t *ret;					\
-	if (pgd_none(*pud))				\
- 		ret = __pmd_alloc(mm, pud, address);	\
- 	else						\
-		ret = pmd_offset(pud, address);		\
- 	ret;						\
-})
+#define pmd_alloc(mm, pud, address) \
+	((unlikely(pgd_none(*(pud))) && __pmd_alloc(mm, pud, address))? \
+ 		NULL: pmd_offset(pud, address))
 
 #define pud_alloc(mm, pgd, address)	(pgd)
 #define pud_offset(pgd, start)		(pgd)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b9fa82b..22c2d69 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -704,10 +704,6 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping,
 }
 
 extern int vmtruncate(struct inode * inode, loff_t offset);
-extern pud_t *FASTCALL(__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address));
-extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address));
-extern pte_t *FASTCALL(pte_alloc_kernel(pmd_t *pmd, unsigned long address));
-extern pte_t *FASTCALL(pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
 extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
 extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
 extern int __handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
@@ -760,32 +756,36 @@ struct shrinker;
 extern struct shrinker *set_shrinker(int, shrinker_t);
 extern void remove_shrinker(struct shrinker *shrinker);
 
-/*
- * On a two-level or three-level page table, this ends up being trivial. Thus
- * the inlining and the symmetry break with pte_alloc_map() that does all
- * of this out-of-line.
- */
+int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
+int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
+int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
+int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
+
 /*
  * The following ifdef needed to get the 4level-fixup.h header to work.
  * Remove it when 4level-fixup.h has been removed.
  */
-#ifdef CONFIG_MMU
-#ifndef __ARCH_HAS_4LEVEL_HACK 
+#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 {
-	if (pgd_none(*pgd))
-		return __pud_alloc(mm, pgd, address);
-	return pud_offset(pgd, address);
+	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
+		NULL: pud_offset(pgd, address);
 }
 
 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {
-	if (pud_none(*pud))
-		return __pmd_alloc(mm, pud, address);
-	return pmd_offset(pud, address);
+	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
+		NULL: pmd_offset(pud, address);
 }
-#endif
-#endif /* CONFIG_MMU */
+#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
+
+#define pte_alloc_map(mm, pmd, address)			\
+	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
+		NULL: pte_offset_map(pmd, address))
+
+#define pte_alloc_kernel(pmd, address)			\
+	((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
+		NULL: pte_offset_kernel(pmd, address))
 
 extern void free_area_init(unsigned long * zones_size);
 extern void free_area_init_node(int nid, pg_data_t *pgdat,