From 182fea8f48332de085c0ae936605cb72671db9f2 Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Tue, 26 Oct 2010 14:21:55 -0700 Subject: [PATCH] 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: Richard Kennedy Reviewed-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/rmap.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 31b2fd7..5c98df6 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -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) /* -- 2.7.4