Re: [PATCH] Allow linker to eliminate unused functions in lib/*

From: Andi Kleen
Date: Mon Jan 11 2010 - 09:24:22 EST


On Mon, Jan 11, 2010 at 10:17:08AM +1100, Dave Chinner wrote:
> On Sat, Jan 09, 2010 at 05:51:56PM +0100, Andi Kleen wrote:
> > > Sneaky.
> > >
> > > It's a bit sad to reduce the code cleanliness and maintainability in
> > > this way, but 1k is 1k.
> >
> > Yes. I had actually hoped for more too. I think it might bring
> > more with -ffunction-sections/--gc-sections, but I haven't tried that.
> >
> > An alternative might be also to give some more of those explicit Kconfig
> > symbols -- then kernels with module loading enabled would benefit more
> > too -- but I haven't investigated how many changes that would need.
> >
> > But even with that it's a reasonable improvement and putting the exports
> > separately is not too bad.
> >
> > > The patch assumes a pre-existing lib-syms.c. Confused.
> >
> > Sorry, some day I'll learn how to operate quilt properly.
> >
> > Updated patch with all files included appended.
>
> Andi, how do you want to handle the overlap between this and the
> list_sort() patch I sent? I'm going to need a list_sort() available
> in the XFS tree well before the 2.6.34 merge window....

Shouldn't be difficult to merge, it's just a few lines. Someone will
do that.

It wou;ld be better if you put it into a separate file like I suggested
earlier though, then the list_sort() could be actually eliminated when
not needed.

-Andi
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