1 files changed, 26 insertions, 5 deletions

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c9583382141a..dda5c7130d93 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -553,6 +553,26 @@ static u64 clocksource_max_deferment(struct clocksource *cs)
 
 #ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
 
+static struct clocksource *clocksource_find_best(bool oneshot)
+{
+        struct clocksource *cs;
+
+        if (!finished_booting || list_empty(&clocksource_list))
+                return NULL;
+
+        /*
+         * We pick the clocksource with the highest rating. If oneshot
+         * mode is active, we pick the highres valid clocksource with
+         * the best rating.
+         */
+        list_for_each_entry(cs, &clocksource_list, list) {
+                if (oneshot && !(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES))
+                        continue;
+                return cs;
+        }
+        return NULL;
+}
+
 /**
  * clocksource_select - Select the best clocksource available
  *
@@ -563,12 +583,14 @@ static u64 clocksource_max_deferment(struct clocksource *cs)
  */
 static void clocksource_select(void)
 {
+        bool oneshot = tick_oneshot_mode_active();
         struct clocksource *best, *cs;
 
-        if (!finished_booting || list_empty(&clocksource_list))
+        /* Find the best suitable clocksource */
+        best = clocksource_find_best(oneshot);
+        if (!best)
                 return;
-        /* First clocksource on the list has the best rating. */
-        best = list_first_entry(&clocksource_list, struct clocksource, list);
+
         /* Check for the override clocksource. */
         list_for_each_entry(cs, &clocksource_list, list) {
                 if (strcmp(cs->name, override_name) != 0)
@@ -578,8 +600,7 @@ static void clocksource_select(void)
                  * capable clocksource if the tick code is in oneshot
                  * mode (highres or nohz)
                  */
-                if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
-                    tick_oneshot_mode_active()) {
+                if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && oneshot) {
                         /* Override clocksource cannot be used. */
                         printk(KERN_WARNING "Override clocksource %s is not "
                                "HRT compatible. Cannot switch while in "