Re: [RFC PATCH v2 0/4] Add support for LZ4-compressed kernel

Russell King - ARM Linux
2013-02-27T09:53:20Z

On Wed, Feb 27, 2013 at 04:36:47PM +0900, Kyungsik Lee wrote:
> Compiler: Linaro ARM gcc 4.6.2
> 2. ARMv7, 1.7GHz based board
> Kernel: linux 3.7
> Uncompressed Kernel Size: 14MB
> Compressed Size Decompression Speed
> LZO 6.0MB 34.1MB/s Old
> ----------------------------------------
> 6.0MB 34.7MB/s New
> 6.0MB 52.2MB/s(UA)
> =============================================
> LZ4 6.5MB 86.7MB/s
> UA: Unaligned memory Access support

That is pretty conclusive - it shows an 8% increase in image size vs a
66% increase in decompression speed. It will take a _lot_ to offset
that increase in decompression speed.

So, what I think is that yes, we should accept LZ4 and drop LZO from
the kernel - the "fast but may not be small" compression title has
clearly been taken by LZ4.

Akpm - what's your thoughts?