Re: [patch] x86: phase out forced inlining

From: Ingo Molnar
Date: Tue Mar 04 2008 - 02:33:33 EST



* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

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

hm, commit 4507a6a59cfc6997e532cd812a8bd244181e6205 does not exist:

fatal: bad object 4507a6a59cfc6997e532cd812a8bd244181e6205

but i suspect it must be something along the lines of the known problem
of really old gcc versions creating huge stackframes? Those pristine gcc
versions were practically unusable for distro kernels anyway (and were
patched by distros) - but i have no problem with restricting this
feature to gcc4x. gcc4x creates more compact -Os code too, so it's
recommended for smaller image sizes.

> I'd suggest that this
>
> > +#ifndef CONFIG_OPTIMIZE_INLINING
>
> become something along the lines of
>
> > +#ifndef CONFIG_OPTIMIZE_INLINING && (__GNUC__ > 3)

good point, fixed that.

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

yeah, instead of littering our include files with those quirks.

Ingo
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