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

Gilad Ben-Yossef gilad at benyossef.com
Tue Jan 3 09:19:12 EST 2012


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.

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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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