Re: [rfc] the kernel workflow & trivial "global -> static" patches

From: Adrian Bunk
Date: Tue May 06 2008 - 07:26:27 EST


On Tue, May 06, 2008 at 01:13:01PM +0200, Andi Kleen wrote:
> Adrian Bunk wrote:
> > On Tue, May 06, 2008 at 02:21:31AM +0200, Andi Kleen wrote:
>...
> >> I could see some advantage from static in future compiler versions
> >> though from better optimization, but it's quite remote.
> >> ...
> >
> > The best case I've actually seen in practice was a variable I made
> > static, and with CONFIG_DEBUG_FOOBAR=n gcc was now able to prove that
> > the value never changed resulting in the variable plus quite a chunk
> > of code no longer emitted.
>
> Sounds like the variable should just have been removed then in the source?

No, an #ifdef CONFIG_DEBUG_FOOBAR guarded some sysctl that allows users
to change the value.

(I'm not claiming this was a common case.)

> -Andi

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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