priorities: move getNonzeroRequests() into util/ package

plugin/pkg/scheduler/algorithm/priorities/util/non_zero.go

@@ -0,0 +1,52 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
+)
+
+// For each of these resources, a pod that doesn't request the resource explicitly
+// will be treated as having requested the amount indicated below, for the purpose
+// of computing priority only. This ensures that when scheduling zero-request pods, such
+// pods will not all be scheduled to the machine with the smallest in-use request,
+// and that when scheduling regular pods, such pods will not see zero-request pods as
+// consuming no resources whatsoever. We chose these values to be similar to the
+// resources that we give to cluster addon pods (#10653). But they are pretty arbitrary.
+// As described in #11713, we use request instead of limit to deal with resource requirements.
+const DefaultMilliCpuRequest int64 = 100             // 0.1 core
+const DefaultMemoryRequest int64 = 200 * 1024 * 1024 // 200 MB
+
+// TODO: Consider setting default as a fixed fraction of machine capacity (take "capacity api.ResourceList"
+// as an additional argument here) rather than using constants
+func GetNonzeroRequests(requests *api.ResourceList) (int64, int64) {
+	var out_millicpu, out_memory int64
+	// Override if un-set, but not if explicitly set to zero
+	if (*requests.Cpu() == resource.Quantity{}) {
+		out_millicpu = DefaultMilliCpuRequest
+	} else {
+		out_millicpu = requests.Cpu().MilliValue()
+	}
+	// Override if un-set, but not if explicitly set to zero
+	if (*requests.Memory() == resource.Quantity{}) {
+		out_memory = DefaultMemoryRequest
+	} else {
+		out_memory = requests.Memory().Value()
+	}
+	return out_millicpu, out_memory
+}