Merge pull request #617 from k82cn/automated-cherry-pick-of-#615-upstream-release-0.4

Automated cherry pick of #615: Handled minAvailable task everytime.

Author: k8s-ci-robot

pkg/scheduler/actions/allocate/allocate.go

@@ -175,13 +175,14 @@ func (alloc *allocateAction) Execute(ssn *framework.Session) {
 				}
 			}
 
-			if assigned {
-				jobs.Push(job)
-				// Handle one assigned task in each loop.
+			if !assigned {
 				break
 			}
 
-			// If current task is not assgined, try to fit all rest tasks.
+			if ssn.JobReady(job) {
+				jobs.Push(job)
+				break
+			}
 		}
 
 		// Added Queue back until no job in Queue.

pkg/scheduler/plugins/gang/gang.go

@@ -107,7 +107,7 @@ func (gp *gangPlugin) OnSessionOpen(ssn *framework.Session) {
 		for _, preemptee := range preemptees {
 			job := ssn.Jobs[preemptee.Job]
 			occupid := readyTaskNum(job)
-			preemptable := job.MinAvailable <= occupid-1
+			preemptable := job.MinAvailable <= occupid-1 || job.MinAvailable == 1
 
 			if !preemptable {
 				glog.V(3).Infof("Can not preempt task <%v/%v> because of gang-scheduling",
@@ -148,17 +148,6 @@ func (gp *gangPlugin) OnSessionOpen(ssn *framework.Session) {
 			return -1
 		}
 
-		if !lReady && !rReady {
-			if lv.CreationTimestamp.Equal(&rv.CreationTimestamp) {
-				if lv.UID < rv.UID {
-					return -1
-				}
-			} else if lv.CreationTimestamp.Before(&rv.CreationTimestamp) {
-				return -1
-			}
-			return 1
-		}
-
 		return 0
 	}