Re: Linux 3.10-rc6

[David Daney <ddaney@caviumnetworks.com>]

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

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).

David Daney



>
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: David Daney <david.daney@cavium.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
>   include/linux/smp.h |   20 ++++++++------------
>   1 file changed, 8 insertions(+), 12 deletions(-)
>
> diff -puN include/linux/smp.h~include-linux-smph-on_each_cpu-switch-back-to-a-macro include/linux/smp.h
> --- a/include/linux/smp.h~include-linux-smph-on_each_cpu-switch-back-to-a-macro
> +++ a/include/linux/smp.h
> @@ -11,7 +11,6 @@
>   #include <linux/list.h>
>   #include <linux/cpumask.h>
>   #include <linux/init.h>
> -#include <linux/irqflags.h>
>
>   extern void cpu_idle(void);
>
> @@ -140,17 +139,14 @@ static inline int up_smp_call_function(s
>   }
>   #define smp_call_function(func, info, wait) \
>   			(up_smp_call_function(func, info))
> -
> -static inline int on_each_cpu(smp_call_func_t func, void *info, int wait)
> -{
> -	unsigned long flags;
> -
> -	local_irq_save(flags);
> -	func(info);
> -	local_irq_restore(flags);
> -	return 0;
> -}
> -
> +#define on_each_cpu(func,info,wait)		\
> +	({					\
> +		unsigned long flags;		\
> +		local_irq_save(flags);		\
> +		func(info);			\
> +		local_irq_restore(flags);	\
> +		0;				\
> +	})
>   /*
>    * Note we still need to test the mask even for UP
>    * because we actually can get an empty mask from
> _
>
>