Hi,
On Sun, Sep 07, 2014 at 11:38:30AM +0800, Huang Ying wrote:
> Only one bit is read in check_valid_map, holding a lock to do that
> doesn't help anything except decreasing performance.
>
> Signed-off-by: Huang, Ying <ying.hu...@intel.com>
> ---
>
> v2: Fixed a build warning.
>
> ---
> fs/f2fs/gc.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -378,14 +378,11 @@ static void put_gc_inode(struct list_hea
> static int check_valid_map(struct f2fs_sb_info *sbi,
> unsigned int segno, int offset)
> {
> - struct sit_info *sit_i = SIT_I(sbi);
> struct seg_entry *sentry;
> int ret;
>
> - mutex_lock(&sit_i->sentry_lock);
> sentry = get_seg_entry(sbi, segno);
> ret = f2fs_test_bit(offset, sentry->cur_valid_map);
> - mutex_unlock(&sit_i->sentry_lock);
> return ret;
The f2fs_test_bit is not atomic, so I'm not sure this is a good approach.
How about introducing rw_semaphore?
> }
>
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