Re: [patch] x86: phase out forced inlining

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 3 Mar 2008 13:13:35 +0100 Ingo Molnar <mingo@elte.hu> wrote:

> +config OPTIMIZE_INLINING
> +	bool "Allow gcc to uninline functions marked 'inline'"
> +	default y
> +	help
> +	  This option determines if the kernel forces gcc to inline the functions
> +	  developers have marked 'inline'. Doing so takes away freedom from gcc to
> +	  do what it thinks is best, which is desirable for the gcc 3.x series of
> +	  compilers. The gcc 4.x series have a rewritten inlining algorithm and
> +	  disabling this option will generate a smaller kernel there. Hopefully
> +	  this algorithm is so good that allowing gcc4 to make the decision can
> +	  become the default in the future, until then this option is there to
> +	  test gcc for this.

urgh.  This will cause whatever problem
4507a6a59cfc6997e532cd812a8bd244181e6205 fixed five years ago to resurface
for incautious gcc-3.x users.

I'd suggest that this

> +#ifndef CONFIG_OPTIMIZE_INLINING

become something along the lines of

> +#ifndef CONFIG_OPTIMIZE_INLINING && (__GNUC__ > 3)

It would be nice to be able to feed the gcc version into the Kconfig logic,
really..