Re: [patch 00/2] improve .text size on gcc 4.0 and newer compilers

Adrian Bunk
2005-12-31T14:38:03Z

On Fri, Dec 30, 2005 at 08:49:16AM +0100, Ingo Molnar wrote:
>
> * Tim Schmielau <tim@physik3.uni-rostock.de> wrote:
>
> > What about the previous suggestion to remove inline from *all* static
> > inline functions in .c files?
>
> i think this is a way too static approach. Why go from one extreme to
> the other, when my 3 simple patches (which arguably create a more
> flexible scenario) gives us savings of 7.7%?

This point only discusses the inline change, which were (without
unit-at-a-time) in your measurements 2.9%.

Your patch might be simple, but it also might have side effects in cases
where we _really_ want the code forced to be inlined. How simple is it
to prove that your uninline patch doesn't cause a subtle breakage
somewhere?

inline's in .c files are nearly always wrong (there might be very few
exceptions), and this should simply be fixed.

Applying Arjan's uninlining patch [1] against 2.6.15-rc5-mm3 (ignoring a
few rejects at applying the patch), I'm getting more than 0.6% .text
savings (this is with a "compile everything .config", without
unit-at-a-time and with -Os).

> Ingo

cu
Adrian

[1] http://www.fenrus.org/noinline

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