From 13e12d14e2dccc7995b8f15a5678a338ab4e6a8c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 8 Jun 2011 15:18:19 -0700 Subject: [PATCH] vfs: reorganize 'struct inode' layout a bit This tries to make the 'struct inode' accesses denser in the data cache by moving a commonly accessed field (i_security) closer to other fields that are accessed often. It also makes 'i_state' just an 'unsigned int' rather than 'unsigned long', since we only use a few bits of that field, and moves it next to the existing 'i_flags' so that we potentially get better structure layout (although depending on config options, i_flags may already have packed in the same word as i_lock, so this improves packing only for the case of spinlock debugging) Out 'struct inode' is still way too big, and we should probably move some other fields around too (the acl fields in particular) for better data cache access density. Other fields (like the inode hash) are likely to be entirely irrelevant under most loads. Signed-off-by: Linus Torvalds --- include/linux/fs.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 646a1836152a..1c777878f1ea 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -744,9 +744,13 @@ struct inode { spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ unsigned int i_flags; + unsigned int i_state; +#ifdef CONFIG_SECURITY + void *i_security; +#endif struct mutex i_mutex; - unsigned long i_state; + unsigned long dirtied_when; /* jiffies of first dirtying */ struct hlist_node i_hash; @@ -798,9 +802,6 @@ struct inode { atomic_t i_readcount; /* struct files open RO */ #endif atomic_t i_writecount; -#ifdef CONFIG_SECURITY - void *i_security; -#endif #ifdef CONFIG_FS_POSIX_ACL struct posix_acl *i_acl; struct posix_acl *i_default_acl; -- 2.30.2