Re: [PATCH 3/6] Add support for LZO-compressed kernels

Albin Tonnerre
2009-08-05T09:19:37Z

On Tue, Aug 04, 2009 at 04:00:43PM -0700, Andrew Morton wrote :
> On Mon, 3 Aug 2009 16:58:18 +0200
> Albin Tonnerre <albin.tonnerre@free-electrons.com> wrote:

> > This is the first part of the lzo patch
> > The lzo compressor is worse than gzip at compression, but faster at
> > extraction. Here are some figures for an ARM board I'm working on:

> > Uncompressed size: 3.24Mo
> > gzip 1.61Mo 0.72s
> > lzo 1.75Mo 0.48s

> > So for a compression ratio that is still relatively close to gzip, it's
> > much faster to extract, at least in that case.

> Is 3.2Mb a typical kernel size for small systems? It sounds large.

This one actually embeds an initramfs which accounts for about half of the size.

> > +#ifdef STATIC

> What is this STATIC thing for?

That's what is currently used to test whether you're compiling the pre-boot
environment. eg. include/linux/decompress/mm.h uses this to determine whether it
should provide a malloc() implementation or simply #define malloc(a) kmalloc(a, GFP_KERNEL),
and a lot of similar things

--
Albin Tonnerre, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.