diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/rmap.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/rmap.h')
-rw-r--r-- | include/linux/rmap.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h new file mode 100644 index 000000000000..11b484e37ac9 --- /dev/null +++ b/include/linux/rmap.h @@ -0,0 +1,118 @@ +#ifndef _LINUX_RMAP_H +#define _LINUX_RMAP_H +/* + * Declarations for Reverse Mapping functions in mm/rmap.c + */ + +#include <linux/config.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/spinlock.h> + +/* + * The anon_vma heads a list of private "related" vmas, to scan if + * an anonymous page pointing to this anon_vma needs to be unmapped: + * the vmas on the list will be related by forking, or by splitting. + * + * Since vmas come and go as they are split and merged (particularly + * in mprotect), the mapping field of an anonymous page cannot point + * directly to a vma: instead it points to an anon_vma, on whose list + * the related vmas can be easily linked or unlinked. + * + * After unlinking the last vma on the list, we must garbage collect + * the anon_vma object itself: we're guaranteed no page can be + * pointing to this anon_vma once its vma list is empty. + */ +struct anon_vma { + spinlock_t lock; /* Serialize access to vma list */ + struct list_head head; /* List of private "related" vmas */ +}; + +#ifdef CONFIG_MMU + +extern kmem_cache_t *anon_vma_cachep; + +static inline struct anon_vma *anon_vma_alloc(void) +{ + return kmem_cache_alloc(anon_vma_cachep, SLAB_KERNEL); +} + +static inline void anon_vma_free(struct anon_vma *anon_vma) +{ + kmem_cache_free(anon_vma_cachep, anon_vma); +} + +static inline void anon_vma_lock(struct vm_area_struct *vma) +{ + struct anon_vma *anon_vma = vma->anon_vma; + if (anon_vma) + spin_lock(&anon_vma->lock); +} + +static inline void anon_vma_unlock(struct vm_area_struct *vma) +{ + struct anon_vma *anon_vma = vma->anon_vma; + if (anon_vma) + spin_unlock(&anon_vma->lock); +} + +/* + * anon_vma helper functions. + */ +void anon_vma_init(void); /* create anon_vma_cachep */ +int anon_vma_prepare(struct vm_area_struct *); +void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *); +void anon_vma_unlink(struct vm_area_struct *); +void anon_vma_link(struct vm_area_struct *); +void __anon_vma_link(struct vm_area_struct *); + +/* + * rmap interfaces called when adding or removing pte of page + */ +void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); +void page_add_file_rmap(struct page *); +void page_remove_rmap(struct page *); + +/** + * page_dup_rmap - duplicate pte mapping to a page + * @page: the page to add the mapping to + * + * For copy_page_range only: minimal extract from page_add_rmap, + * avoiding unnecessary tests (already checked) so it's quicker. + */ +static inline void page_dup_rmap(struct page *page) +{ + atomic_inc(&page->_mapcount); +} + +/* + * Called from mm/vmscan.c to handle paging out + */ +int page_referenced(struct page *, int is_locked, int ignore_token); +int try_to_unmap(struct page *); + +/* + * Used by swapoff to help locate where page is expected in vma. + */ +unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); + +#else /* !CONFIG_MMU */ + +#define anon_vma_init() do {} while (0) +#define anon_vma_prepare(vma) (0) +#define anon_vma_link(vma) do {} while (0) + +#define page_referenced(page,l,i) TestClearPageReferenced(page) +#define try_to_unmap(page) SWAP_FAIL + +#endif /* CONFIG_MMU */ + +/* + * Return values of try_to_unmap + */ +#define SWAP_SUCCESS 0 +#define SWAP_AGAIN 1 +#define SWAP_FAIL 2 + +#endif /* _LINUX_RMAP_H */ |