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| author | Andrew Morton <akpm@linux-foundation.org> | 2009-01-09 12:27:08 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-11 03:41:58 +0100 |
| commit | 53ce3d9564908794ae7dd32969089b57df5fc098 (patch) | |
| tree | d0eb540d9743155eff6d3c454db3493bf75c9023 | |
| parent | abede81c4fb2e3b85d8760f25e3da39d2c69a134 (diff) | |
| download | lwn-53ce3d9564908794ae7dd32969089b57df5fc098.tar.gz lwn-53ce3d9564908794ae7dd32969089b57df5fc098.zip | |
smp_call_function_single(): be slightly less stupid
If you do
smp_call_function_single(expression-with-side-effects, ...)
then expression-with-side-effects never gets evaluated on UP builds.
As always, implementing it in C is the correct thing to do.
While we're there, uninline it for size and possible header dependency
reasons.
And create a new kernel/up.c, as a place in which to put
uniprocessor-specific code and storage. It should mirror kernel/smp.c.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/smp.h | 13 | ||||
| -rw-r--r-- | kernel/Makefile | 6 | ||||
| -rw-r--r-- | kernel/up.c | 18 |
3 files changed, 26 insertions, 11 deletions
diff --git a/include/linux/smp.h b/include/linux/smp.h index b82466968101..715196b09d67 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -24,6 +24,9 @@ struct call_single_data { /* total number of cpus in this system (may exceed NR_CPUS) */ extern unsigned int total_cpus; +int smp_call_function_single(int cpuid, void (*func) (void *info), void *info, + int wait); + #ifdef CONFIG_SMP #include <linux/preempt.h> @@ -79,8 +82,6 @@ smp_call_function_mask(cpumask_t mask, void(*func)(void *info), void *info, return 0; } -int smp_call_function_single(int cpuid, void (*func) (void *info), void *info, - int wait); void __smp_call_function_single(int cpuid, struct call_single_data *data); /* @@ -140,14 +141,6 @@ static inline int up_smp_call_function(void (*func)(void *), void *info) static inline void smp_send_reschedule(int cpu) { } #define num_booting_cpus() 1 #define smp_prepare_boot_cpu() do {} while (0) -#define smp_call_function_single(cpuid, func, info, wait) \ -({ \ - WARN_ON(cpuid != 0); \ - local_irq_disable(); \ - (func)(info); \ - local_irq_enable(); \ - 0; \ -}) #define smp_call_function_mask(mask, func, info, wait) \ (up_smp_call_function(func, info)) #define smp_call_function_many(mask, func, info, wait) \ diff --git a/kernel/Makefile b/kernel/Makefile index 2921d90ce32f..2aebc4cd7878 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -40,7 +40,11 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o -obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o +ifeq ($(CONFIG_USE_GENERIC_SMP_HELPERS),y) +obj-y += smp.o +else +obj-y += up.o +endif obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o diff --git a/kernel/up.c b/kernel/up.c new file mode 100644 index 000000000000..ce62cc9e9f71 --- /dev/null +++ b/kernel/up.c @@ -0,0 +1,18 @@ +/* + * Uniprocessor-only support functions. The counterpart to kernel/smp.c + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/smp.h> + +int smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int wait) +{ + WARN_ON(cpuid != 0); + local_irq_disable(); + (func)(info); + local_irq_enable(); + return 0; +} +EXPORT_SYMBOL(smp_call_function_single); |