[PATCH 10/21] mm: ptd_alloc inline and out
From: Hugh Dickins
Date: Wed Oct 12 2005 - 19:56:50 EST
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@xxxxxxxxxxx>
---
include/asm-generic/4level-fixup.h | 11 +---
include/linux/mm.h | 38 +++++++--------
mm/memory.c | 93 +++++++++++++++----------------------
mm/mremap.c | 7 --
4 files changed, 61 insertions(+), 88 deletions(-)
--- mm09/include/asm-generic/4level-fixup.h 2005-06-17 20:48:29.000000000 +0100
+++ mm10/include/asm-generic/4level-fixup.h 2005-10-11 23:56:11.000000000 +0100
@@ -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)
--- mm09/include/linux/mm.h 2005-10-11 23:55:54.000000000 +0100
+++ mm10/include/linux/mm.h 2005-10-11 23:56:11.000000000 +0100
@@ -709,10 +709,6 @@ static inline void unmap_shared_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);
@@ -765,32 +761,36 @@ 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,
--- mm09/mm/memory.c 2005-10-11 23:55:54.000000000 +0100
+++ mm10/mm/memory.c 2005-10-11 23:56:11.000000000 +0100
@@ -280,50 +280,39 @@ void free_pgtables(struct mmu_gather **t
}
}
-pte_t fastcall *pte_alloc_map(struct mm_struct *mm, pmd_t *pmd,
- unsigned long address)
+int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
{
- if (!pmd_present(*pmd)) {
- struct page *new;
+ struct page *new;
- spin_unlock(&mm->page_table_lock);
- new = pte_alloc_one(mm, address);
- spin_lock(&mm->page_table_lock);
- if (!new)
- return NULL;
- /*
- * Because we dropped the lock, we should re-check the
- * entry, as somebody else could have populated it..
- */
- if (pmd_present(*pmd)) {
- pte_free(new);
- goto out;
- }
+ spin_unlock(&mm->page_table_lock);
+ new = pte_alloc_one(mm, address);
+ spin_lock(&mm->page_table_lock);
+ if (!new)
+ return -ENOMEM;
+
+ if (pmd_present(*pmd)) /* Another has populated it */
+ pte_free(new);
+ else {
mm->nr_ptes++;
inc_page_state(nr_page_table_pages);
pmd_populate(mm, pmd, new);
}
-out:
- return pte_offset_map(pmd, address);
+ return 0;
}
-pte_t fastcall * pte_alloc_kernel(pmd_t *pmd, unsigned long address)
+int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
{
- if (!pmd_present(*pmd)) {
- pte_t *new;
-
- new = pte_alloc_one_kernel(&init_mm, address);
- if (!new)
- return NULL;
+ pte_t *new = pte_alloc_one_kernel(&init_mm, address);
+ if (!new)
+ return -ENOMEM;
- spin_lock(&init_mm.page_table_lock);
- if (pmd_present(*pmd))
- pte_free_kernel(new);
- else
- pmd_populate_kernel(&init_mm, pmd, new);
- spin_unlock(&init_mm.page_table_lock);
- }
- return pte_offset_kernel(pmd, address);
+ spin_lock(&init_mm.page_table_lock);
+ if (pmd_present(*pmd)) /* Another has populated it */
+ pte_free_kernel(new);
+ else
+ pmd_populate_kernel(&init_mm, pmd, new);
+ spin_unlock(&init_mm.page_table_lock);
+ return 0;
}
static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss)
@@ -2093,7 +2082,7 @@ int __handle_mm_fault(struct mm_struct *
* Allocate page upper directory.
* We've already handled the fast-path in-line.
*/
-pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
+int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
{
pud_t *new;
@@ -2103,19 +2092,17 @@ pud_t fastcall *__pud_alloc(struct mm_st
if (!new) {
if (mm != &init_mm) /* Temporary bridging hack */
spin_lock(&mm->page_table_lock);
- return NULL;
+ return -ENOMEM;
}
spin_lock(&mm->page_table_lock);
- if (pgd_present(*pgd)) {
+ if (pgd_present(*pgd)) /* Another has populated it */
pud_free(new);
- goto out;
- }
- pgd_populate(mm, pgd, new);
- out:
+ else
+ pgd_populate(mm, pgd, new);
if (mm == &init_mm) /* Temporary bridging hack */
spin_unlock(&mm->page_table_lock);
- return pud_offset(pgd, address);
+ return 0;
}
#endif /* __PAGETABLE_PUD_FOLDED */
@@ -2124,7 +2111,7 @@ pud_t fastcall *__pud_alloc(struct mm_st
* Allocate page middle directory.
* We've already handled the fast-path in-line.
*/
-pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
+int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
{
pmd_t *new;
@@ -2134,28 +2121,24 @@ pmd_t fastcall *__pmd_alloc(struct mm_st
if (!new) {
if (mm != &init_mm) /* Temporary bridging hack */
spin_lock(&mm->page_table_lock);
- return NULL;
+ return -ENOMEM;
}
spin_lock(&mm->page_table_lock);
#ifndef __ARCH_HAS_4LEVEL_HACK
- if (pud_present(*pud)) {
+ if (pud_present(*pud)) /* Another has populated it */
pmd_free(new);
- goto out;
- }
- pud_populate(mm, pud, new);
+ else
+ pud_populate(mm, pud, new);
#else
- if (pgd_present(*pud)) {
+ if (pgd_present(*pud)) /* Another has populated it */
pmd_free(new);
- goto out;
- }
- pgd_populate(mm, pud, new);
+ else
+ pgd_populate(mm, pud, new);
#endif /* __ARCH_HAS_4LEVEL_HACK */
-
- out:
if (mm == &init_mm) /* Temporary bridging hack */
spin_unlock(&mm->page_table_lock);
- return pmd_offset(pud, address);
+ return 0;
}
#endif /* __PAGETABLE_PMD_FOLDED */
--- mm09/mm/mremap.c 2005-10-11 23:54:33.000000000 +0100
+++ mm10/mm/mremap.c 2005-10-11 23:56:11.000000000 +0100
@@ -51,7 +51,6 @@ static pmd_t *alloc_new_pmd(struct mm_st
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd = NULL;
- pte_t *pte;
/*
* We do need page_table_lock: because allocators expect that.
@@ -66,12 +65,8 @@ static pmd_t *alloc_new_pmd(struct mm_st
if (!pmd)
goto out;
- pte = pte_alloc_map(mm, pmd, addr);
- if (!pte) {
+ if (!pmd_present(*pmd) && __pte_alloc(mm, pmd, addr))
pmd = NULL;
- goto out;
- }
- pte_unmap(pte);
out:
spin_unlock(&mm->page_table_lock);
return pmd;
-
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