mm: speed up cancel_dirty_page() for clean pages

[sfrench/cifs-2.6.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 91b46f99b4d2189291ddc47ba47690ba79db6251..c7b1d617dff6851b121539610981a491a4d0d415 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -95,6 +95,15 @@ extern int mmap_rnd_compat_bits __read_mostly;
 #define mm_forbids_zeropage(X) (0)
 #endif
 
+/*
+ * On some architectures it is expensive to call memset() for small sizes.
+ * Those architectures should provide their own implementation of "struct page"
+ * zeroing by defining this macro in <asm/pgtable.h>.
+ */
+#ifndef mm_zero_struct_page
+#define mm_zero_struct_page(pp)  ((void)memset((pp), 0, sizeof(struct page)))
+#endif
+
 /*
  * Default maximum number of active map areas, this limits the number of vmas
  * per mm struct. Users can overwrite this number by sysctl but there is a
@@ -1431,7 +1440,13 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
                          struct bdi_writeback *wb);
 int set_page_dirty(struct page *page);
 int set_page_dirty_lock(struct page *page);
-void cancel_dirty_page(struct page *page);
+void __cancel_dirty_page(struct page *page);
+static inline void cancel_dirty_page(struct page *page)
+{
+       /* Avoid atomic ops, locking, etc. when not actually needed. */
+       if (PageDirty(page))
+               __cancel_dirty_page(page);
+}
 int clear_page_dirty_for_io(struct page *page);
 
 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
@@ -1599,26 +1614,32 @@ static inline int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
 int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
 #endif
 
-#ifdef __PAGETABLE_PUD_FOLDED
+#if defined(__PAGETABLE_PUD_FOLDED) || !defined(CONFIG_MMU)
 static inline int __pud_alloc(struct mm_struct *mm, p4d_t *p4d,
                                                unsigned long address)
 {
        return 0;
 }
+static inline void mm_inc_nr_puds(struct mm_struct *mm) {}
+static inline void mm_dec_nr_puds(struct mm_struct *mm) {}
+
 #else
 int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
-#endif
 
-#if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
-static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
-                                               unsigned long address)
+static inline void mm_inc_nr_puds(struct mm_struct *mm)
 {
-       return 0;
+       atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
 }
 
-static inline void mm_nr_pmds_init(struct mm_struct *mm) {}
+static inline void mm_dec_nr_puds(struct mm_struct *mm)
+{
+       atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
+}
+#endif
 
-static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
+#if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
+static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
+                                               unsigned long address)
 {
        return 0;
 }
@@ -1629,25 +1650,47 @@ static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
 #else
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 
-static inline void mm_nr_pmds_init(struct mm_struct *mm)
+static inline void mm_inc_nr_pmds(struct mm_struct *mm)
 {
-       atomic_long_set(&mm->nr_pmds, 0);
+       atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
 }
 
-static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
+static inline void mm_dec_nr_pmds(struct mm_struct *mm)
 {
-       return atomic_long_read(&mm->nr_pmds);
+       atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
 }
+#endif
 
-static inline void mm_inc_nr_pmds(struct mm_struct *mm)
+#ifdef CONFIG_MMU
+static inline void mm_pgtables_bytes_init(struct mm_struct *mm)
 {
-       atomic_long_inc(&mm->nr_pmds);
+       atomic_long_set(&mm->pgtables_bytes, 0);
 }
 
-static inline void mm_dec_nr_pmds(struct mm_struct *mm)
+static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
+{
+       return atomic_long_read(&mm->pgtables_bytes);
+}
+
+static inline void mm_inc_nr_ptes(struct mm_struct *mm)
+{
+       atomic_long_add(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
+}
+
+static inline void mm_dec_nr_ptes(struct mm_struct *mm)
 {
-       atomic_long_dec(&mm->nr_pmds);
+       atomic_long_sub(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
 }
+#else
+
+static inline void mm_pgtables_bytes_init(struct mm_struct *mm) {}
+static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
+{
+       return 0;
+}
+
+static inline void mm_inc_nr_ptes(struct mm_struct *mm) {}
+static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
 #endif
 
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
@@ -2002,6 +2045,12 @@ extern int __meminit __early_pfn_to_nid(unsigned long pfn,
                                        struct mminit_pfnnid_cache *state);
 #endif
 
+#ifdef CONFIG_HAVE_MEMBLOCK
+void zero_resv_unavail(void);
+#else
+static inline void zero_resv_unavail(void) {}
+#endif
+
 extern void set_dma_reserve(unsigned long new_dma_reserve);
 extern void memmap_init_zone(unsigned long, int, unsigned long,
                                unsigned long, enum memmap_context);