diff options
author | Steven Whitehouse <swhiteho@redhat.com> | 2006-09-28 08:29:59 -0400 |
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committer | Steven Whitehouse <swhiteho@redhat.com> | 2006-09-28 08:29:59 -0400 |
commit | 185a257f2f73bcd89050ad02da5bedbc28fc43fa (patch) | |
tree | 5e32586114534ed3f2165614cba3d578f5d87307 /include/linux/mm_types.h | |
parent | 3f1a9aaeffd8d1cbc5ab9776c45cbd66af1c9699 (diff) | |
parent | a77c64c1a641950626181b4857abb701d8f38ccc (diff) |
Merge branch 'master' into gfs2
Diffstat (limited to 'include/linux/mm_types.h')
-rw-r--r-- | include/linux/mm_types.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h new file mode 100644 index 00000000000..c3852fd4a1c --- /dev/null +++ b/include/linux/mm_types.h @@ -0,0 +1,67 @@ +#ifndef _LINUX_MM_TYPES_H +#define _LINUX_MM_TYPES_H + +#include <linux/types.h> +#include <linux/threads.h> +#include <linux/list.h> +#include <linux/spinlock.h> + +struct address_space; + +/* + * Each physical page in the system has a struct page associated with + * it to keep track of whatever it is we are using the page for at the + * moment. Note that we have no way to track which tasks are using + * a page, though if it is a pagecache page, rmap structures can tell us + * who is mapping it. + */ +struct page { + unsigned long flags; /* Atomic flags, some possibly + * updated asynchronously */ + atomic_t _count; /* Usage count, see below. */ + atomic_t _mapcount; /* Count of ptes mapped in mms, + * to show when page is mapped + * & limit reverse map searches. + */ + union { + struct { + unsigned long private; /* Mapping-private opaque data: + * usually used for buffer_heads + * if PagePrivate set; used for + * swp_entry_t if PageSwapCache; + * indicates order in the buddy + * system if PG_buddy is set. + */ + struct address_space *mapping; /* If low bit clear, points to + * inode address_space, or NULL. + * If page mapped as anonymous + * memory, low bit is set, and + * it points to anon_vma object: + * see PAGE_MAPPING_ANON below. + */ + }; +#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS + spinlock_t ptl; +#endif + }; + pgoff_t index; /* Our offset within mapping. */ + struct list_head lru; /* Pageout list, eg. active_list + * protected by zone->lru_lock ! + */ + /* + * On machines where all RAM is mapped into kernel address space, + * we can simply calculate the virtual address. On machines with + * highmem some memory is mapped into kernel virtual memory + * dynamically, so we need a place to store that address. + * Note that this field could be 16 bits on x86 ... ;) + * + * Architectures with slow multiplication can define + * WANT_PAGE_VIRTUAL in asm/page.h + */ +#if defined(WANT_PAGE_VIRTUAL) + void *virtual; /* Kernel virtual address (NULL if + not kmapped, ie. highmem) */ +#endif /* WANT_PAGE_VIRTUAL */ +}; + +#endif /* _LINUX_MM_TYPES_H */ |