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| author | Eric Dumazet <dada1@cosmosbay.com> | 2006-12-06 20:38:53 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 08:39:41 -0800 |
| commit | 83b7b44e1c1e9e493ccd4146558481ab5af0116a (patch) | |
| tree | 8da0b4d9601d27073b14964fd43f64bb73540e22 | |
| parent | ea82c74093f48b28e632d03eeff22faf99727a8c (diff) | |
| download | linux-83b7b44e1c1e9e493ccd4146558481ab5af0116a.tar.bz2 | |
[PATCH] fs: reorder some 'struct inode' fields to speedup i_size manipulations
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@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/linux/fs.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index d791bae9de9c..3a1927e516d0 100644 --- a/include/linux/fs.h +++ b/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 }; /* |