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

[Ingo Molnar]

* David Howells <dhowells@xxxxxxxxxx> wrote:

> +#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ

> +#ifdef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ

> +#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ

I think the myriad of arch switches and the resulting #ifdef noise, just 
to get rid of a _single_ unused global function, is pretty lame. (and 
that's of course not your fault)

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.

	Ingo
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