[PATCH] hrtimers: optimize softirq runqueues
The hrtimer softirq is called from the timer softirq every tick. Retrieve the
current time from xtime and wall_to_monotonic instead of calling
base->get_time() for each timer base. Store the time in the base structure
and provide a hook once clock source abstractions are in place and to keep the
code open for new base clocks.
Based on a patch from: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 6401c31..64e2754 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -72,14 +72,16 @@
/**
* struct hrtimer_base - the timer base for a specific clock
*
- * @index: clock type index for per_cpu support when moving a timer
- * to a base on another cpu.
- * @lock: lock protecting the base and associated timers
- * @active: red black tree root node for the active timers
- * @first: pointer to the timer node which expires first
- * @resolution: the resolution of the clock, in nanoseconds
- * @get_time: function to retrieve the current time of the clock
- * @curr_timer: the timer which is executing a callback right now
+ * @index: clock type index for per_cpu support when moving a timer
+ * to a base on another cpu.
+ * @lock: lock protecting the base and associated timers
+ * @active: red black tree root node for the active timers
+ * @first: pointer to the timer node which expires first
+ * @resolution: the resolution of the clock, in nanoseconds
+ * @get_time: function to retrieve the current time of the clock
+ * @get_sofirq_time: function to retrieve the current time from the softirq
+ * @curr_timer: the timer which is executing a callback right now
+ * @softirq_time: the time when running the hrtimer queue in the softirq
*/
struct hrtimer_base {
clockid_t index;
@@ -88,7 +90,9 @@
struct rb_node *first;
ktime_t resolution;
ktime_t (*get_time)(void);
+ ktime_t (*get_softirq_time)(void);
struct hrtimer *curr_timer;
+ ktime_t softirq_time;
};
/*