Re: [PATCH] Compress kernel modules on installation.

Sam Ravnborg
2009-01-18T21:02:43Z

On Fri, Dec 26, 2008 at 08:50:34PM +0100, Jan Engelhardt wrote:
>
> On Friday 2008-12-26 20:48, Sam Ravnborg wrote:
> >> >>
> >> >> 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.
> >>
> >> I recently started compressing my kernel modules and that saved me
> >> at least 70 MB of disk space on mostlyallmodconfig.
> >> (And no, the argument of disks being cheap is not so true with
> >> CF or SSD.)
> >> Distro is lazy and wants to wait for upstream to have it,
> >> so is there any chance of getting this proposal in?
> >
> >Steve said he wanted to try to make the solution more
> >scalable so I am awaiting a new patch.
>
> Hm, all I needed was this patch. It might fire up some people,
> but it's got all the scalability I could think of..

Can I ask you to redo this patch.
I want a way to swith off compression, but it should default be enable.
So if KBUILD_MODULE_NOCOMPRESS is undefined we will compress the modules
when we install them.

Something like:

cmd_modules_install = \
mkdir -p $(2); cp $@ $(2) ; \
$(mod_strip_cmd) $(2)/$(notdir $@) \
$(if $(KBUILD_MODULES_NOCOMPRESS),, ;gzip -9f $(2)/$(notdir $@))

And add documentation to Documentation/kbuild/kbuild.txt too...

Thanks,
Sam