Re: [RFC PATCH] x86: Unify include/asm-x86/linkage_[32|64].h

From: Ingo Molnar
Date: Tue Dec 04 2007 - 17:27:45 EST



* Harvey Harrison <harvey.harrison@xxxxxxxxx> wrote:

> On Tue, 2007-12-04 at 22:32 +0100, Ingo Molnar wrote:
> > * Harvey Harrison <harvey.harrison@xxxxxxxxx> wrote:
> >
> > > I'm not sure if the definition of asmlinkage and prevent_tail_call can
> > > be omitted as well and let the linux/linkage.h version get picked up
> > > instead.
> >
> > no, we cannot remove them - asmlinkage is needed for the syscall
> > entry (and other entry code) to work, the and the prevent_tail_call
> > works around a compiler bug. (which might or might not be fixed in
> > latest gcc - but we generally dont remove workarounds unless we are
> > really sure it's fine.)
>
> OK, but if this patch is acceptable, then there is no more places in
> the tree that define the FASTCALL macro, other than the empty default
> in include/linux/linkage.h. So I think a second step would be to
> start to get rid of FASTCALL callers elsewhere in the tree...thoughts?

the removal of FASTCALL is fine: the default (and only) compiler model
for x86 (32-bit) is regparm(3), so the regparm(3) macro is equivalent to
the empty one in linux/linkage.h.

btw., removal of FASTCALL from the tree is worthwile after this: it
should probably be done via the -mm tree, because it's more of a generic
kernel matter than an arch/x86 matter.

Ingo
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