Commit 182fea8f authored by Richard Kennedy's avatar Richard Kennedy Committed by Linus Torvalds

mm: remove alignment padding from anon_vma on (some) 64 bit builds

Reorder structure anon_vma to remove alignment padding on 64 builds when
(CONFIG_KSM || CONFIG_MIGRATION).
This will shrink the size of the anon_vma structure from 40 to 32 bytes
& allow more objects per slab in its kmem_cache.

Under slub the objects in the anon_vma kmem_cache will then be 40 bytes
with 102 objects per slab.  (On v2.6.36 without this patch,the size is 48
bytes and 85 objects/slab.)
Signed-off-by: default avatarRichard Kennedy <richard@rsk.demon.co.uk>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ea05c844
......@@ -25,8 +25,8 @@
* pointing to this anon_vma once its vma list is empty.
*/
struct anon_vma {
spinlock_t lock; /* Serialize access to vma list */
struct anon_vma *root; /* Root of this anon_vma tree */
spinlock_t lock; /* Serialize access to vma list */
#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION)
/*
......
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