diff options
author | Andrew Morton <akpm@osdl.org> | 2006-01-08 01:04:36 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-08 20:14:04 -0800 |
commit | 349aef0bc4c7f07d685c977e12d0e2d0b5d0e6db (patch) | |
tree | 6bb266ed8826bb4e7355a07a0092acb3d5d92647 /include/linux | |
parent | 59d9136b9844d3a0376d93c945ab280decedb323 (diff) | |
download | linux-stable-349aef0bc4c7f07d685c977e12d0e2d0b5d0e6db.tar.gz linux-stable-349aef0bc4c7f07d685c977e12d0e2d0b5d0e6db.tar.bz2 linux-stable-349aef0bc4c7f07d685c977e12d0e2d0b5d0e6db.zip |
[PATCH] shrink struct page
Reduce the size of the pageframe for NR_CPUS>4, CONFIG_PREEMPT back to the
minimal size by unionising both ->private and ->mapping with the pagetable
lock.
It uses an anonymous struct and hence requires gcc-3.x.
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/mm.h | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 7ff54242c5d7..df80e63903b5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -223,24 +223,27 @@ struct page { * & limit reverse map searches. */ union { - unsigned long private; /* Mapping-private opaque data: - * usually used for buffer_heads - * if PagePrivate set; used for - * swp_entry_t if PageSwapCache - * When page is free, this indicates - * order in the buddy system. - */ + struct { + unsigned long private; /* Mapping-private opaque data: + * usually used for buffer_heads + * if PagePrivate set; used for + * swp_entry_t if PageSwapCache. + * When page is free, this + * indicates order in the buddy + * system. + */ + 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; + spinlock_t ptl; #endif - } u; - 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. - */ + }; pgoff_t index; /* Our offset within mapping. */ struct list_head lru; /* Pageout list, eg. active_list * protected by zone->lru_lock ! @@ -261,8 +264,8 @@ struct page { #endif /* WANT_PAGE_VIRTUAL */ }; -#define page_private(page) ((page)->u.private) -#define set_page_private(page, v) ((page)->u.private = (v)) +#define page_private(page) ((page)->private) +#define set_page_private(page, v) ((page)->private = (v)) /* * FIXME: take this include out, include page-flags.h in @@ -815,7 +818,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a * overflow into the next struct page (as it might with DEBUG_SPINLOCK). * When freeing, reset page->mapping so free_pages_check won't complain. */ -#define __pte_lockptr(page) &((page)->u.ptl) +#define __pte_lockptr(page) &((page)->ptl) #define pte_lock_init(_page) do { \ spin_lock_init(__pte_lockptr(_page)); \ } while (0) |