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| author | Thomas Gleixner <tglx@linutronix.de> | 2011-06-15 10:36:06 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-05-14 18:38:15 (GMT) |
| commit | e5d85d672ec063f0e9bb7e9a58ab5bc0db41f8d5 (patch) | |
| tree | 9cab67340ab25fe3fe4de9db042a1461eac2f9c8 /include/linux | |
| parent | 8fbe5399232b6c30f7b964a8736eb981d0b4e4ce (diff) | |
| download | linux-fsl-qoriq-e5d85d672ec063f0e9bb7e9a58ab5bc0db41f8d5.tar.xz | |
hotplug: Lightweight get online cpus
get_online_cpus() is a heavy weight function which involves a global
mutex. migrate_disable() wants a simpler construct which prevents only
a CPU from going doing while a task is in a migrate disabled section.
Implement a per cpu lockless mechanism, which serializes only in the
real unplug case on a global mutex. That serialization affects only
tasks on the cpu which should be brought down.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cpu.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 801ff9e..0c2b05c 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -179,6 +179,8 @@ extern void get_online_cpus(void); extern void put_online_cpus(void); extern void cpu_hotplug_disable(void); extern void cpu_hotplug_enable(void); +extern void pin_current_cpu(void); +extern void unpin_current_cpu(void); #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri) #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) @@ -206,6 +208,8 @@ static inline void cpu_hotplug_done(void) {} #define put_online_cpus() do { } while (0) #define cpu_hotplug_disable() do { } while (0) #define cpu_hotplug_enable() do { } while (0) +static inline void pin_current_cpu(void) { } +static inline void unpin_current_cpu(void) { } #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) /* These aren't inline functions due to a GCC bug. */ #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) |