Re: [PATCH] Compress kernel modules on installation.

[Sam Ravnborg <sam@ravnborg.org>]

On Mon, Feb 25, 2008 at 09:42:09PM +0000, Steve Brokenshire wrote:
> Hi,
> 
> (I've sent this to the linux-kbuild and linux-kernel lists as this
> patch modifies the Makefile.modinst file. I also don't subscribe to the 
> linux-kbuild and linux-kernel mailing lists so can I have any replies
> CC'ed to me please)
> 
> This patch allows kernel modules to be compressed when 'make
> modules_install' is run after being copied to
> the /lib/module/<version>/<...> directory which is useful if you have
> module-init-tools installed with --enable-zlib. This patch adds an
> option (MODULE_COMPRESS) to the kernel configuration file (specifically
> init/Kconfig) so that the kernel modules will compressed if
> MODULE_COMPRESS is set.
> 
> When MODULE_COMPRESS is set the output of 'make modules_install' will
> go as the following:
> 
> INSTALL  drivers/fs/xfs/xfs.ko
> COMPRESS drivers/fs/xfs/xfs.ko
> INSTALL  drivers/fs/fat/fat.ko
> COMPRESS drivers/fs/fat/fat.ko
> ...
> 
> I've tested my patch on kernel versions 2.6.24.2, 2.6.24-git12, 2.6.23.14 and
> 2.6.19 and they compile, install and compress into the respective
> module directories without any errors.
> 
> I've also tested this with the uvcvideo (linux-uvc) kernel module (from
> the SVN branch and with kernel versions 2.6.24.2, 2.6.24-git12, 2.6.23.14 and
> 2.6.19) as that uses Kbuild properly when installing the module and
> after installing the uvcvideo the module is then compressed.
> Unfortunately, I couldn't find any other kernel modules which used the
> Kbuild system for installing their kernel modules. :(
> 
> I've included include/config/auto.conf in Makefile.modinst so that it
> can check if MODULE_COMPRESS is set when installing the kernel modules.

Should we mention this possibility in Documentation/kbuild/modules.txt also?

Otherwise from a quick scan it looks OK.
As module-init-tols are our userspae counterpart we should align the
functionality with that tool.
I assume this gives us a simple choice of compression method and naming.

	Sam