Re: [f2fs-dev] [PATCH 1/2] f2fs: do not select same victim right again

From: Chao Yu
Date: Sun Sep 08 2019 - 22:57:24 EST


On 2019/9/9 9:25, Jaegeuk Kim wrote:
> GC must avoid select the same victim again.

Blocks in previous victim will occupy addition free segment, I doubt after this
change, FGGC may encounter out-of-free space issue more frequently.

Thanks,

>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/gc.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index e88f98ddf396..15ca8bbb0b22 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -274,6 +274,9 @@ static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
> static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
> unsigned int segno, struct victim_sel_policy *p)
> {
> + if (sbi->cur_victim_sec == GET_SEC_FROM_SEG(sbi, segno))
> + return UINT_MAX;
> +
> if (p->alloc_mode == SSR)
> return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
>
> @@ -1326,9 +1329,6 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> round++;
> }
>
> - if (gc_type == FG_GC)
> - sbi->cur_victim_sec = NULL_SEGNO;
> -
> if (sync)
> goto stop;
>
>