Re: [PATCH 2/3] FRV: Permit __do_IRQ() to be dispensed with

[Ingo Molnar <mingo@elte.hu>]

* Daniel Walker <dwalker@mvista.com> wrote:

> On Sat, 2006-09-09 at 07:12 +0200, Ingo Molnar wrote:
> 
> > The real solution would be to use gcc -ffunction-sections plus ld 
> > --gc-sections to automatically get rid of unused global functions, at 
> > link time. I'm wondering how hard it would be to enhance kbuild to do 
> > that - x86_64 already uses -ffunction-sections (if CONFIG_REORDER), so 
> > the big question is how usable is ld --gc-sections. Such a feature would 
> > be quite important for embedded systems (and for RAM footprint in 
> > general) as it would save a significant amount of .text and .data.
> 
> A patch to do this was submitted already by Marcelo Tosatti ..
> 
> http://lkml.org/lkml/2006/6/4/169

ah, i missed that patch in the June lock validator frenzy. The results 
are astounding:

>> vmlinux shrinks from 1090389 to 983933 bytes, or 106k (~= 10%).

Andrew, Linus, Kai, Sam: a must-have feature! This saves more kernel 
kernel image RAM than all the other kernel shrinking efforts of the past 
2 years combined - at zero cost.

	Ingo