On 06/17/2013 01:59 PM, Andrew Morton wrote:
On Mon, 17 Jun 2013 13:48:16 -0700 David Daney <dda...@caviumnetworks.com>
wrote:
On 06/17/2013 01:30 PM, Andrew Morton wrote:
[...]
From: Andrew Morton <a...@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.
Although all these points are true, they are not why I wrote the patch.
The key difference, for me, between the SMP and !SMP versions is that
the !SMP version unconditionally enables interrupts, and this enabling
interrupts breaks my kernel
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?
If the patch is reverted, I will do that.
David Daney
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