diff options
| author | Eric Sandeen | 2010-08-05 07:46:37 +0200 |
|---|---|---|
| committer | Theodore Ts'o | 2010-08-05 07:46:37 +0200 |
| commit | 0cfc9255a1efb0467de2162950197750570ecec0 (patch) | |
| tree | 3bb2510d8b6d373d7db3a49bcda3cbbebd10330e /fs/ext4/ext4.h | |
| parent | jbd2: Remove t_handle_lock from start_this_handle() (diff) | |
| download | kernel-qcow2-linux-0cfc9255a1efb0467de2162950197750570ecec0.tar.gz kernel-qcow2-linux-0cfc9255a1efb0467de2162950197750570ecec0.tar.xz kernel-qcow2-linux-0cfc9255a1efb0467de2162950197750570ecec0.zip | |
ext4: re-inline ext4_rec_len_(to|from)_disk functions
commit 3d0518f4, "ext4: New rec_len encoding for very
large blocksizes" made several changes to this path, but from
a perf perspective, un-inlining ext4_rec_len_from_disk() seems
most significant. This function is called from ext4_check_dir_entry(),
which on a file-creation workload is called extremely often.
I tested this with bonnie:
# bonnie++ -u root -s 0 -f -x 200 -d /mnt/test -n 32
(this does 200 iterations) and got this for the file creations:
ext4 stock: Average = 21206.8 files/s
ext4 inlined: Average = 22346.7 files/s (+5%)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index ed14e1db0832..e03841d9f30b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1412,6 +1412,43 @@ struct ext4_dir_entry_2 { #define EXT4_MAX_REC_LEN ((1<<16)-1) /* + * If we ever get support for fs block sizes > page_size, we'll need + * to remove the #if statements in the next two functions... + */ +static inline unsigned int +ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize) +{ + unsigned len = le16_to_cpu(dlen); + +#if (PAGE_CACHE_SIZE >= 65536) + if (len == EXT4_MAX_REC_LEN || len == 0) + return blocksize; + return (len & 65532) | ((len & 3) << 16); +#else + return len; +#endif +} + +static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize) +{ + if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3)) + BUG(); +#if (PAGE_CACHE_SIZE >= 65536) + if (len < 65536) + return cpu_to_le16(len); + if (len == blocksize) { + if (blocksize == 65536) + return cpu_to_le16(EXT4_MAX_REC_LEN); + else + return cpu_to_le16(0); + } + return cpu_to_le16((len & 65532) | ((len >> 16) & 3)); +#else + return cpu_to_le16(len); +#endif +} + +/* * Hash Tree Directory indexing * (c) Daniel Phillips, 2001 */ @@ -1636,8 +1673,6 @@ extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long); extern int ext4_ext_migrate(struct inode *); /* namei.c */ -extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize); -extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize); extern int ext4_orphan_add(handle_t *, struct inode *); extern int ext4_orphan_del(handle_t *, struct inode *); extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, |