[RFC PATCH 8/9] smp: refactor on_each_cpu to void returning func

From: Gilad Ben-Yossef
Date: Tue Jan 03 2012 - 09:21:40 EST


on_each_cpu returns the retunr value of smp_call_function
which is hard coded to 0.

Refactor on_each_cpu to a void function and the few callers
that check the return value to save compares and branches.

CC: Michal Nazarewicz <mina86@xxxxxxxxxx>
CC: David Airlie <airlied@xxxxxxxx>
CC: dri-devel@xxxxxxxxxxxxxxxxxxxxx
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Grant Likely <grant.likely@xxxxxxxxxxxx>
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CC: Tony Luck <tony.luck@xxxxxxxxx>
CC: Fenghua Yu <fenghua.yu@xxxxxxxxx>
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CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
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---
include/linux/smp.h | 7 +++----
kernel/smp.c | 6 ++----
2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/include/linux/smp.h b/include/linux/smp.h
index 8cc38d3..050ddd4 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -99,7 +99,7 @@ static inline void call_function_init(void) { }
/*
* Call a function on all processors
*/
-int on_each_cpu(smp_call_func_t func, void *info, int wait);
+void on_each_cpu(smp_call_func_t func, void *info, int wait);

/*
* Mark the boot cpu "online" so that it can call console drivers in
@@ -126,12 +126,11 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
#define smp_call_function(func, info, wait) \
(up_smp_call_function(func, info))
#define on_each_cpu(func,info,wait) \
- ({ \
+ { \
local_irq_disable(); \
func(info); \
local_irq_enable(); \
- 0; \
- })
+ }
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
#define smp_prepare_boot_cpu() do {} while (0)
diff --git a/kernel/smp.c b/kernel/smp.c
index db197d6..f66a1b2 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -687,17 +687,15 @@ void __init smp_init(void)
* early_boot_irqs_disabled is set. Use local_irq_save/restore() instead
* of local_irq_disable/enable().
*/
-int on_each_cpu(void (*func) (void *info), void *info, int wait)
+void on_each_cpu(void (*func) (void *info), void *info, int wait)
{
unsigned long flags;
- int ret = 0;

preempt_disable();
- ret = smp_call_function(func, info, wait);
+ smp_call_function(func, info, wait);
local_irq_save(flags);
func(info);
local_irq_restore(flags);
preempt_enable();
- return ret;
}
EXPORT_SYMBOL(on_each_cpu);
--
1.7.0.4

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