Re: Linux 3.10-rc6

From: David Daney
Date: Mon Jun 17 2013 - 16:48:26 EST

On 06/17/2013 01:30 PM, Andrew Morton wrote:

From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
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:

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@xxxxxxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

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

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