The patch titled
fs: reorder some 'struct inode' fields to speedup i_size manipulations
has been added to the -mm tree. Its filename is
fs-reorder-some-struct-inode-fields-to-speedup-i_size-manipulations.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: fs: reorder some 'struct inode' fields to speedup i_size manipulations
From: Eric Dumazet <dada1@xxxxxxxxxxxxx>
On 32bits SMP platforms, 64bits i_size is protected by a seqcount
(i_size_seqcount).
When i_size is read or written, i_size_seqcount is read/written as well, so
it make sense to group these two fields together in the same cache line.
This patch moves i_size_seqcount next to i_size, and also moves i_version
to let offsetof(struct inode, i_size) being 0x40 instead of 0x3c (for
32bits platforms).
For 64 bits platforms, i_size_seqcount doesnt exist, and the move of a
'long i_version' should not introduce a new hole because of padding.
Signed-off-by: Eric Dumazet <dada1@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/fs.h | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff -puN include/linux/fs.h~fs-reorder-some-struct-inode-fields-to-speedup-i_size-manipulations include/linux/fs.h
--- a/include/linux/fs.h~fs-reorder-some-struct-inode-fields-to-speedup-i_size-manipulations
+++ a/include/linux/fs.h
@@ -548,12 +548,15 @@ struct inode {
uid_t i_uid;
gid_t i_gid;
dev_t i_rdev;
+ unsigned long i_version;
loff_t i_size;
+#ifdef __NEED_I_SIZE_ORDERED
+ seqcount_t i_size_seqcount;
+#endif
struct timespec i_atime;
struct timespec i_mtime;
struct timespec i_ctime;
unsigned int i_blkbits;
- unsigned long i_version;
blkcnt_t i_blocks;
unsigned short i_bytes;
spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
@@ -598,9 +601,6 @@ struct inode {
void *i_security;
#endif
void *i_private; /* fs or device private pointer */
-#ifdef __NEED_I_SIZE_ORDERED
- seqcount_t i_size_seqcount;
-#endif
};
/*
_
Patches currently in -mm which might be from dada1@xxxxxxxxxxxxx are
git-net.patch
rcu-add-a-prefetch-in-rcu_do_batch.patch
dont-insert-pipe-dentries-into-dentry_hashtable.patch
dcache-avoid-rcu-for-never-hashed-dentries.patch
net-dont-insert-socket-dentries-into-dentry_hashtable.patch
fs-reorder-some-struct-inode-fields-to-speedup-i_size-manipulations.patch
-
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