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smp: Implement kick_all_cpus_sync()

Will replace the misnomed cpu_idle_wait() function which is copied a gazillion times all over arch/*

Thomas Gleixner committed 14 years ago

Commit f37f4351 parent 9cd75e12 files · +27 −0Browse files

Unified · Split

2 files
  1. include/linux/smp.h +4 −0
  2. kernel/smp.c +23 −0
include/linux/smp.h+4−0
@@ -81,6 +81,8 @@ void __smp_call_function_single(int cpuid, struct call_single_data *data, · 80 unmodified lines
81int smp_call_function_any(const struct cpumask *mask,81int smp_call_function_any(const struct cpumask *mask,
82 smp_call_func_t func, void *info, int wait);82 smp_call_func_t func, void *info, int wait);
83 83
84void kick_all_cpus_sync(void);
85
84/*86/*
85 * Generic and arch helpers87 * Generic and arch helpers
86 */88 */
@@ -192,6 +194,8 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, · 105 unmodified lines
192 return smp_call_function_single(0, func, info, wait);194 return smp_call_function_single(0, func, info, wait);
193}195}
194 196
197static inline void kick_all_cpus_sync(void) { }
198
195#endif /* !SMP */199#endif /* !SMP */
196 200
197/*201/*
kernel/smp.c+23−0
@@ -795,3 +795,26 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), · 794 unmodified lines
795 }795 }
796}796}
797EXPORT_SYMBOL(on_each_cpu_cond);797EXPORT_SYMBOL(on_each_cpu_cond);
798
799static void do_nothing(void *unused)
800{
801}
802
803/**
804 * kick_all_cpus_sync - Force all cpus out of idle
805 *
806 * Used to synchronize the update of pm_idle function pointer. It's
807 * called after the pointer is updated and returns after the dummy
808 * callback function has been executed on all cpus. The execution of
809 * the function can only happen on the remote cpus after they have
810 * left the idle function which had been called via pm_idle function
811 * pointer. So it's guaranteed that nothing uses the previous pointer
812 * anymore.
813 */
814void kick_all_cpus_sync(void)
815{
816 /* Make sure the change is visible before we kick the cpus */
817 smp_mb();
818 smp_call_function(do_nothing, NULL, 1);
819}
820EXPORT_SYMBOL_GPL(kick_all_cpus_sync);