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hrtimer: Store cpu-number in struct hrtimer_cpu_base

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In lowres mode, hrtimers are serviced by the tick instead of a clock
event. Now it works well as long as the tick stays periodic but we
must also make sure that the hrtimers are serviced in dynticks mode.

Part of that job consist in kicking a dynticks hrtimer target in order
to make it reconsider the next tick to schedule to correctly handle the
hrtimer's expiring time. And that part isn't handled by the hrtimers
subsystem.

To prepare for fixing this, we need __hrtimer_start_range_ns() to be
able to resolve the CPU target associated to a hrtimer's object
'cpu_base' so that the kick can be centralized there.

So lets store it in the 'struct hrtimer_cpu_base' to resolve the CPU
without overhead. It is set once at CPU's online notification.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1403393357-2070-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Viresh Kumar 2014-06-22 01:29:15 +02:00 committed by Thomas Gleixner
parent 9f6d9baaa8
commit cddd02489f
2 changed files with 3 additions and 0 deletions
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2
include/linux/hrtimer.h
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@ -165,6 +165,7 @@ enum hrtimer_base_type {
* struct hrtimer_cpu_base - the per cpu clock bases
* @lock: lock protecting the base and associated clock bases
* and timers
* @cpu: cpu number
* @active_bases: Bitfield to mark bases with active timers
* @clock_was_set: Indicates that clock was set from irq context.
* @expires_next: absolute time of the next event which was scheduled
@ -179,6 +180,7 @@ enum hrtimer_base_type {
*/
struct hrtimer_cpu_base {
raw_spinlock_t lock;
unsigned int cpu;
unsigned int active_bases;
unsigned int clock_was_set;
#ifdef CONFIG_HIGH_RES_TIMERS

1
kernel/time/hrtimer.c
View File

@ -1680,6 +1680,7 @@ static void init_hrtimers_cpu(int cpu)
timerqueue_init_head(&cpu_base->clock_base[i].active);
}
cpu_base->cpu = cpu;
hrtimer_init_hres(cpu_base);
}