Re: [f2fs-dev] [PATCH v5] f2fs: introduce fragment allocation mode mount option

[Chao Yu]

On 2021/9/30 2:12, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@xxxxxxxxxx>
>
> Added two options into "mode=" mount option to make it possible for
> developers to simulate filesystem fragmentation/after-GC situation
> itself. The developers use these modes to understand filesystem
> fragmentation/after-GC condition well, and eventually get some
> insights to handle them better.
>
> "fragment:segment": f2fs allocates a new segment in ramdom position.
> 		With this, we can simulate the after-GC condition.
> "fragment:block" : We can scatter block allocation with
> 		"max_fragment_chunk" and "max_fragment_hole" sysfs
> 		nodes. f2fs will allocate 1..<max_fragment_chunk>
> 		blocks in a chunk and make a hole in the length of
> 		1..<max_fragment_hole> by turns	in a newly allocated
> 		free segment. Plus, this mode implicitly enables
> 		"fragment:segment" option for more randomness.
>
> Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,