hrtimer: optimize the softirq time optimization

The previous optimization did not take the case into account where a
clock provides its own softirq_get_time() function.

Check for the availablitiy of the clock get time function first and
then check if we need to retrieve the time for both clocks via
hrtimer_softirq_gettime() to avoid a double evaluation of time in that
case as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 70d4adc..f78777a 100644 (file)
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1254,14 +1254,13 @@ void hrtimer_run_queues(void)
                if (!base->first)
                        continue;
 
-               if (gettime) {
+               if (base->get_softirq_time)
+                       base->softirq_time = base->get_softirq_time();
+               else if (gettime) {
                        hrtimer_get_softirq_time(cpu_base);
                        gettime = 0;
                }
 
-               if (base->get_softirq_time)
-                       base->softirq_time = base->get_softirq_time();
-
                spin_lock(&cpu_base->lock);
 
                while ((node = base->first)) {