Merge pull request #54778 from stewart-yu/addexplain

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. Add comment for preempt sunction. **What this PR does / why we need it**: Add explain for preempt sunction. **Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes # **Special notes for your reviewer**: **Release note**: ```release-note NONE ```

Merge pull request #54778 from stewart-yu/addexplain
aed9ad4b · Kubernetes Submit Queue · GitHub · 5691a8d4 · bc2845ee · aed9ad4b
Unverified Commit aed9ad4b authored Nov 04, 2017 by Kubernetes Submit Queue Committed by GitHub Nov 04, 2017
Hide whitespace changes
Inline Side-by-side

Showing with 3 additions and 0 deletions

scheduler.go plugin/pkg/scheduler/scheduler.go +3 -0

No files found.
--- a/plugin/pkg/scheduler/scheduler.go
+++ b/plugin/pkg/scheduler/scheduler.go
@@ -184,6 +184,9 @@ func (sched *Scheduler) schedule(pod *v1.Pod) (string, error) {
 	return host, err
 }

+// preempt tries to create room for a pod that has failed to schedule, by preempting lower priority pods if possible.
+// If it succeeds, it adds the name of the node where preemption has happened to the pod annotations.
+// It returns the node name and an error if any.
 func (sched *Scheduler) preempt(preemptor *v1.Pod, scheduleErr error) (string, error) {
 	if !utilfeature.DefaultFeatureGate.Enabled(features.PodPriority) {
 		glog.V(3).Infof("Pod priority feature is not enabled. No preemption is performed.")