Re: [PATCH 7/7] erofs: lzma compression support

From: Chao Yu
Date: Tue Oct 19 2021 - 09:04:16 EST


On 2021/10/11 5:31, Gao Xiang wrote:
From: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>

Add MicroLZMA support in order to maximize compression ratios for
specific scenarios. For example, it's useful for low-end embedded
boards and as a secondary algorithm in a file for specific access
patterns.

MicroLZMA is a new container format for raw LZMA1, which was created
by Lasse Collin aiming to minimize old LZMA headers and get rid of
unnecessary EOPM (end of payload marker) as well as to enable
fixed-sized output compression, especially for 4KiB pclusters.

Similar to LZ4, inplace I/O approach is used to minimize runtime
memory footprint when dealing with I/O. Overlapped decompression is
handled with 1) bounced buffer for data under processing or 2) extra
short-lived pages from the on-stack pagepool which will be shared in
the same read request (128KiB for example).

Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>

Acked-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,