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>

1 files changed, 3 insertions, 4 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 70d4adc74639..f78777abe769 100644
--- 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)) {