diff options
| author | Yu Chao <chao2.yu@samsung.com> | 2013-09-12 11:17:51 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-09-24 17:45:48 +0900 |
| commit | e76eebee70948060d80b5f9edd2d97062049df53 (patch) | |
| tree | 0e553ac012ec66bbd50cc1ab0f3165c307b1b0e0 | |
| parent | 4a10c2ac2f368583138b774ca41fac4207911983 (diff) | |
| download | linux-e76eebee70948060d80b5f9edd2d97062049df53.tar.bz2 | |
f2fs: optimize fs_lock for better performance
There is a performance problem: when all sbi->fs_lock are holded, then
all the following threads may get the same next_lock value from sbi->next_lock_num
in function mutex_lock_op, and wait for the same lock(fs_lock[next_lock]),
it may cause performance reduce.
So we move the sbi->next_lock_num++ before getting lock, this will average the
following threads if all sbi->fs_lock are holded.
v1-->v2:
Drop the needless spin_lock as Jaegeuk suggested.
Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Yu Chao <chao2.yu@samsung.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
| -rw-r--r-- | fs/f2fs/f2fs.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 608f0df5b919..7fd99d8bd2ff 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -544,15 +544,15 @@ static inline void mutex_unlock_all(struct f2fs_sb_info *sbi) static inline int mutex_lock_op(struct f2fs_sb_info *sbi) { - unsigned char next_lock = sbi->next_lock_num % NR_GLOBAL_LOCKS; + unsigned char next_lock; int i = 0; for (; i < NR_GLOBAL_LOCKS; i++) if (mutex_trylock(&sbi->fs_lock[i])) return i; + next_lock = sbi->next_lock_num++ % NR_GLOBAL_LOCKS; mutex_lock(&sbi->fs_lock[next_lock]); - sbi->next_lock_num++; return next_lock; } |