Re: [PATCH] f2fs: fix heap mode to reset it back

[Chao Yu <yuchao0@huawei.com>]

Hi Yunlong,

On 2018/1/29 11:37, Yunlong Song wrote:
> Commit 7a20b8a61eff81bdb7097a578752a74860e9d142 ("f2fs: allocate node
> and hot data in the beginning of partition") introduces another mount
> option, heap, to reset it back. But it does not do anything for heap
> mode, so fix it.

I think Jaegeuk did three things in that patch:
a) add missing heap mount option handling in ->show_options.
b) set noheap by default.
c) change allocation policy to the one that allocate hotdata & nodes in the
front of main are intensively.

They could be separated, independent, and I don't see such intention that
we can only use c) the new introduced allocation policy in noheap mode.

Anyway, I think Jaegeuk can help to double check that.

Thanks,

> 
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
> ---
>  fs/f2fs/gc.c      | 5 +++--
>  fs/f2fs/segment.c | 3 ++-
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index aa720cc..b9d93fd 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -191,8 +191,9 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
>  	if (gc_type != FG_GC && p->max_search > sbi->max_victim_search)
>  		p->max_search = sbi->max_victim_search;
>  
> -	/* let's select beginning hot/small space first */
> -	if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
> +	/* let's select beginning hot/small space first in no_heap mode*/
> +	if (test_opt(sbi, NOHEAP) &&
> +		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
>  		p->offset = 0;
>  	else
>  		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index e5739ce..77a48c4 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2167,7 +2167,8 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
>  	if (sbi->segs_per_sec != 1)
>  		return CURSEG_I(sbi, type)->segno;
>  
> -	if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
> +	if (test_opt(sbi, NOHEAP) &&
> +		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
>  		return 0;
>  
>  	if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
>