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author | Theodore Ts'o <tytso@mit.edu> | 2010-11-02 09:34:50 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-02 10:38:30 -0400 |
commit | eb8abb927ae2fd1730e24ea94cd9527f3c086292 (patch) | |
tree | e0ae72934040e8d840db503c311ac070d9850bc8 /fs/ext4 | |
parent | 7fe19da4ca38fc20cdbc7020fcf2eca8fc756410 (diff) | |
download | op-kernel-dev-eb8abb927ae2fd1730e24ea94cd9527f3c086292.zip op-kernel-dev-eb8abb927ae2fd1730e24ea94cd9527f3c086292.tar.gz |
ext4: Remove useless spinlock in ext4_getattr()
Linus noted, and complained to me, that doing while lots of "git diff"'s
of kernel sources, these spinlocks were responsible for 27% of the
spinlock cost on his two-processor system as reported by perf.
Git was doing lots of parallel stats, and this was putting a lot of
pressure on ext4_getattr(). A spinlock to protect a single
memory-to-memory copy is pointless, so remove it.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ext4')
-rw-r--r-- | fs/ext4/inode.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1916164..4d78342 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5410,9 +5410,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, * will return the blocks that include the delayed allocation * blocks for this file. */ - spin_lock(&EXT4_I(inode)->i_block_reservation_lock); delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks; - spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9; return 0; |