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Date:   Thu, 21 Oct 2021 19:29:33 +0800
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Subject: Re: [f2fs-dev] [PATCH v5] f2fs: introduce fragment allocation mode
 mount option
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To:     Daeho Jeong <daeho43@gmail.com>, linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc:     Daeho Jeong <daehojeong@google.com>
References: <20210929181203.1606675-1-daeho43@gmail.com>
From:   Chao Yu <chao@kernel.org>
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On 2021/9/30 2:12, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
> 
> 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@google.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,