Re: Linux 3.10-rc6

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 17 Jun 2013 13:48:16 -0700 David Daney <ddaney@caviumnetworks.com> wrote:

> On 06/17/2013 01:30 PM, Andrew Morton wrote:
> [...]
> >
> > From: Andrew Morton <akpm@linux-foundation.org>
> > Subject: include/linux/smp.h:on_each_cpu(): switch back to a macro
> >
> > f21afc25f9ed4 ("smp.h: Use local_irq_{save,restore}() in !SMP version of
> > on_each_cpu()") converted on_each_cpu() to a C function.  This required
> > inclusion of irqflags.h, which broke ia64 and mn10300 (at least) due to
> > header ordering hell.
> >
> > Switch on_each_cpu() back to a macro to fix this.
> 
> FYI:  I have already sent a pair of patches that fix the include 
> dependencies:
> 
> https://lkml.org/lkml/2013/6/16/113
> https://lkml.org/lkml/2013/6/17/422

I wasn't cc'ed.

> Obviously, it is Linus' choice as to how best to handle the failure, but 
> I think it is important to know that there are two options (fixing ia64 
> and mn10300, or reverting the patch).

I certainly prefer the inline function over a crappy macro.  The
additional nested include is regrettable - more complexity.

Also, it's good to have the SMP and non-SMP versions either both using
macros or both using C.  Having them different can cause irritating
unused-variable compilation warnings when using the macro version.

I think switch-back-to-a-macro is simplest and safest for now.  Perhaps
you can queue a 3.11 patch which restores the C function and fixes up
mn10300 and ia64?