diff options
| author | Sebastien Buisson <sebastien.buisson@bull.net> | 2014-10-09 15:29:38 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 22:26:02 -0400 |
| commit | 86cf78d73de8c6bfa89804b91ee0ace71a459961 (patch) | |
| tree | 2cb7facefd7c5609bde031400b8a4130da67ef21 | |
| parent | 2c0346a36cc8ac6cb85ab585964590974c84bdf0 (diff) | |
fs/buffer.c: increase the buffer-head per-CPU LRU size
Increase the buffer-head per-CPU LRU size to allow efficient filesystem
operations that access many blocks for each transaction. For example,
creating a file in a large ext4 directory with quota enabled will access
multiple buffer heads and will overflow the LRU at the default 8-block LRU
size:
* parent directory inode table block (ctime, nlinks for subdirs)
* new inode bitmap
* inode table block
* 2 quota blocks
* directory leaf block (not reused, but pollutes one cache entry)
* 2 levels htree blocks (only one is reused, other pollutes cache)
* 2 levels indirect/index blocks (only one is reused)
The buffer-head per-CPU LRU size is raised to 16, as it shows in metadata
performance benchmarks up to 10% gain for create, 4% for lookup and 7% for
destroy.
Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/buffer.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 7bd5c4685e98..44c14a87750e 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1253,7 +1253,7 @@ static struct buffer_head *__bread_slow(struct buffer_head *bh) * a local interrupt disable for that. */ -#define BH_LRU_SIZE 8 +#define BH_LRU_SIZE 16 struct bh_lru { struct buffer_head *bhs[BH_LRU_SIZE]; |