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authorArun R Bharadwaj <arun@linux.vnet.ibm.com>2009-04-16 12:16:41 +0530
committerThomas Gleixner <tglx@linutronix.de>2009-05-13 16:52:42 +0200
commiteea08f32adb3f97553d49a4f79a119833036000a (patch)
tree4e6af5185309d7abe49a8fa19634ea38582381e4 /kernel/time/clockevents.c
parentcd1bb94b4a0531e8211a3774f17de831f8285f76 (diff)
timers: Logic to move non pinned timers
* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch migrates all non pinned timers and hrtimers to the current idle load balancer, from all the idle CPUs. Timers firing on busy CPUs are not migrated. While migrating hrtimers, care should be taken to check if migrating a hrtimer would result in a latency or not. So we compare the expiry of the hrtimer with the next timer interrupt on the target cpu and migrate the hrtimer only if it expires *after* the next interrupt on the target cpu. So, added a clockevents_get_next_event() helper function to return the next_event on the target cpu's clock_event_device. [ tglx: cleanups and simplifications ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/clockevents.c')
-rw-r--r--kernel/time/clockevents.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index d13be216a79..ab20ded013b 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -18,6 +18,7 @@
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/sysdev.h>
+#include <linux/tick.h>
/* The registered clock event devices */
static LIST_HEAD(clockevent_devices);
@@ -251,4 +252,15 @@ void clockevents_notify(unsigned long reason, void *arg)
spin_unlock(&clockevents_lock);
}
EXPORT_SYMBOL_GPL(clockevents_notify);
+
+ktime_t clockevents_get_next_event(int cpu)
+{
+ struct tick_device *td;
+ struct clock_event_device *dev;
+
+ td = &per_cpu(tick_cpu_device, cpu);
+ dev = td->evtdev;
+
+ return dev->next_event;
+}
#endif