Merge pull request #89070 from alculquicondor/static-partitioning

Add chunk size option to ParallelizeUntil

pkg/scheduler/BUILD

@@ -123,6 +123,7 @@ filegroup(
         "//pkg/scheduler/framework:all-srcs",
         "//pkg/scheduler/internal/cache:all-srcs",
         "//pkg/scheduler/internal/heap:all-srcs",
+        "//pkg/scheduler/internal/parallelize:all-srcs",
         "//pkg/scheduler/internal/queue:all-srcs",
         "//pkg/scheduler/listers:all-srcs",
         "//pkg/scheduler/metrics:all-srcs",

pkg/scheduler/core/BUILD

@@ -13,6 +13,7 @@ go_library(
         "//pkg/scheduler/apis/config:go_default_library",
         "//pkg/scheduler/framework/v1alpha1:go_default_library",
         "//pkg/scheduler/internal/cache:go_default_library",
+        "//pkg/scheduler/internal/parallelize:go_default_library",
         "//pkg/scheduler/internal/queue:go_default_library",
         "//pkg/scheduler/listers:go_default_library",
         "//pkg/scheduler/metrics:go_default_library",
@@ -28,7 +29,6 @@ go_library(
         "//staging/src/k8s.io/client-go/listers/core/v1:go_default_library",
         "//staging/src/k8s.io/client-go/listers/policy/v1beta1:go_default_library",
         "//staging/src/k8s.io/client-go/rest:go_default_library",
-        "//staging/src/k8s.io/client-go/util/workqueue:go_default_library",
         "//staging/src/k8s.io/kube-scheduler/extender/v1:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
         "//vendor/k8s.io/utils/trace:go_default_library",

pkg/scheduler/core/generic_scheduler.go

@@ -28,6 +28,7 @@ import (
 	"time"
 
 	"k8s.io/klog"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 
 	v1 "k8s.io/api/core/v1"
 	policy "k8s.io/api/policy/v1beta1"
@@ -35,7 +36,6 @@ import (
 	"k8s.io/apimachinery/pkg/labels"
 	corelisters "k8s.io/client-go/listers/core/v1"
 	policylisters "k8s.io/client-go/listers/policy/v1beta1"
-	"k8s.io/client-go/util/workqueue"
 	extenderv1 "k8s.io/kube-scheduler/extender/v1"
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
@@ -479,7 +479,7 @@ func (g *genericScheduler) findNodesThatPassFilters(ctx context.Context, prof *p
 
 	// Stops searching for more nodes once the configured number of feasible nodes
 	// are found.
-	workqueue.ParallelizeUntil(ctx, 16, len(allNodes), checkNode)
+	parallelize.Until(ctx, len(allNodes), checkNode)
 	processedNodes := int(filteredLen) + len(statuses)
 	g.nextStartNodeIndex = (g.nextStartNodeIndex + processedNodes) % len(allNodes)
 
@@ -870,7 +870,7 @@ func (g *genericScheduler) selectNodesForPreemption(
 			resultLock.Unlock()
 		}
 	}
-	workqueue.ParallelizeUntil(context.TODO(), 16, len(potentialNodes), checkNode)
+	parallelize.Until(ctx, len(potentialNodes), checkNode)
 	return nodeToVictims, nil
 }
 

pkg/scheduler/framework/plugins/interpodaffinity/BUILD

@@ -11,6 +11,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/scheduler/framework/v1alpha1:go_default_library",
+        "//pkg/scheduler/internal/parallelize:go_default_library",
         "//pkg/scheduler/listers:go_default_library",
         "//pkg/scheduler/nodeinfo:go_default_library",
         "//pkg/scheduler/util:go_default_library",
@@ -20,7 +21,6 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
-        "//staging/src/k8s.io/client-go/util/workqueue:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
         "//vendor/k8s.io/utils/pointer:go_default_library",
     ],

pkg/scheduler/framework/plugins/interpodaffinity/filtering.go

@@ -25,9 +25,9 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 	schedutil "k8s.io/kubernetes/pkg/scheduler/util"
 )
@@ -240,7 +240,7 @@ func getTPMapMatchingExistingAntiAffinity(pod *v1.Pod, allNodes []*nodeinfo.Node
 			}
 		}
 	}
-	workqueue.ParallelizeUntil(ctx, 16, len(allNodes), processNode)
+	parallelize.Until(ctx, len(allNodes), processNode)
 
 	if err := errCh.ReceiveError(); err != nil {
 		return nil, err
@@ -304,7 +304,7 @@ func getTPMapMatchingIncomingAffinityAntiAffinity(pod *v1.Pod, allNodes []*nodei
 			appendResult(node.Name, nodeTopologyPairsAffinityPodsMap, nodeTopologyPairsAntiAffinityPodsMap)
 		}
 	}
-	workqueue.ParallelizeUntil(context.Background(), 16, len(allNodes), processNode)
+	parallelize.Until(context.Background(), len(allNodes), processNode)
 
 	return topologyPairsAffinityPodsMap, topologyToMatchedExistingAntiAffinityTerms, nil
 }

pkg/scheduler/framework/plugins/interpodaffinity/scoring.go

@@ -22,9 +22,9 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 	schedutil "k8s.io/kubernetes/pkg/scheduler/util"
 )
@@ -259,7 +259,7 @@ func (pl *InterPodAffinity) PreScore(
 			pl.Unlock()
 		}
 	}
-	workqueue.ParallelizeUntil(ctx, 16, len(allNodes), processNode)
+	parallelize.Until(ctx, len(allNodes), processNode)
 	if err := errCh.ReceiveError(); err != nil {
 		return framework.NewStatus(framework.Error, err.Error())
 	}

pkg/scheduler/framework/plugins/podtopologyspread/BUILD

@@ -13,6 +13,7 @@ go_library(
     deps = [
         "//pkg/scheduler/framework/plugins/helper:go_default_library",
         "//pkg/scheduler/framework/v1alpha1:go_default_library",
+        "//pkg/scheduler/internal/parallelize:go_default_library",
         "//pkg/scheduler/listers:go_default_library",
         "//pkg/scheduler/nodeinfo:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
@@ -25,7 +26,6 @@ go_library(
         "//staging/src/k8s.io/client-go/informers:go_default_library",
         "//staging/src/k8s.io/client-go/listers/apps/v1:go_default_library",
         "//staging/src/k8s.io/client-go/listers/core/v1:go_default_library",
-        "//staging/src/k8s.io/client-go/util/workqueue:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
     ],
 )

pkg/scheduler/framework/plugins/podtopologyspread/filtering.go

@@ -24,10 +24,10 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog"
 	pluginhelper "k8s.io/kubernetes/pkg/scheduler/framework/plugins/helper"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 )
 
@@ -267,7 +267,7 @@ func (pl *PodTopologySpread) calPreFilterState(pod *v1.Pod) (*preFilterState, er
 			addTopologyPairMatchNum(pair, matchTotal)
 		}
 	}
-	workqueue.ParallelizeUntil(context.Background(), 16, len(allNodes), processNode)
+	parallelize.Until(context.Background(), len(allNodes), processNode)
 
 	// calculate min match for each topology pair
 	for i := 0; i < len(constraints); i++ {

pkg/scheduler/framework/plugins/podtopologyspread/scoring.go

@@ -25,10 +25,10 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog"
 	pluginhelper "k8s.io/kubernetes/pkg/scheduler/framework/plugins/helper"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 )
 
 const preScoreStateKey = "PreScore" + Name
@@ -153,7 +153,7 @@ func (pl *PodTopologySpread) PreScore(
 			atomic.AddInt64(state.TopologyPairToPodCounts[pair], matchSum)
 		}
 	}
-	workqueue.ParallelizeUntil(ctx, 16, len(allNodes), processAllNode)
+	parallelize.Until(ctx, len(allNodes), processAllNode)
 
 	cycleState.Write(preScoreStateKey, state)
 	return nil

pkg/scheduler/framework/v1alpha1/BUILD

@@ -15,6 +15,7 @@ go_library(
     deps = [
         "//pkg/controller/volume/scheduling:go_default_library",
         "//pkg/scheduler/apis/config:go_default_library",
+        "//pkg/scheduler/internal/parallelize:go_default_library",
         "//pkg/scheduler/listers:go_default_library",
         "//pkg/scheduler/metrics:go_default_library",
         "//pkg/scheduler/nodeinfo:go_default_library",
@@ -26,7 +27,6 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//staging/src/k8s.io/client-go/informers:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
-        "//staging/src/k8s.io/client-go/util/workqueue:go_default_library",
         "//staging/src/k8s.io/component-base/metrics:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
         "//vendor/sigs.k8s.io/yaml:go_default_library",

pkg/scheduler/framework/v1alpha1/framework.go

@@ -28,10 +28,10 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/informers"
 	clientset "k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog"
 	"k8s.io/kubernetes/pkg/controller/volume/scheduling"
 	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+	"k8s.io/kubernetes/pkg/scheduler/internal/parallelize"
 	schedulerlisters "k8s.io/kubernetes/pkg/scheduler/listers"
 	"k8s.io/kubernetes/pkg/scheduler/metrics"
 	schedulernodeinfo "k8s.io/kubernetes/pkg/scheduler/nodeinfo"
@@ -513,7 +513,7 @@ func (f *framework) RunScorePlugins(ctx context.Context, state *CycleState, pod
 	errCh := schedutil.NewErrorChannel()
 
 	// Run Score method for each node in parallel.
-	workqueue.ParallelizeUntil(ctx, 16, len(nodes), func(index int) {
+	parallelize.Until(ctx, len(nodes), func(index int) {
 		for _, pl := range f.scorePlugins {
 			nodeName := nodes[index].Name
 			s, status := f.runScorePlugin(ctx, pl, state, pod, nodeName)
@@ -534,7 +534,7 @@ func (f *framework) RunScorePlugins(ctx context.Context, state *CycleState, pod
 	}
 
 	// Run NormalizeScore method for each ScorePlugin in parallel.
-	workqueue.ParallelizeUntil(ctx, 16, len(f.scorePlugins), func(index int) {
+	parallelize.Until(ctx, len(f.scorePlugins), func(index int) {
 		pl := f.scorePlugins[index]
 		nodeScoreList := pluginToNodeScores[pl.Name()]
 		if pl.ScoreExtensions() == nil {
@@ -554,7 +554,7 @@ func (f *framework) RunScorePlugins(ctx context.Context, state *CycleState, pod
 	}
 
 	// Apply score defaultWeights for each ScorePlugin in parallel.
-	workqueue.ParallelizeUntil(ctx, 16, len(f.scorePlugins), func(index int) {
+	parallelize.Until(ctx, len(f.scorePlugins), func(index int) {
 		pl := f.scorePlugins[index]
 		// Score plugins' weight has been checked when they are initialized.
 		weight := f.pluginNameToWeightMap[pl.Name()]

pkg/scheduler/internal/parallelize/BUILD

@@ -0,0 +1,23 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["parallelism.go"],
+    importpath = "k8s.io/kubernetes/pkg/scheduler/internal/parallelize",
+    visibility = ["//pkg/scheduler:__subpackages__"],
+    deps = ["//staging/src/k8s.io/client-go/util/workqueue:go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

pkg/scheduler/internal/parallelize/parallelism.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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 parallelize
+
+import (
+	"context"
+	"math"
+
+	"k8s.io/client-go/util/workqueue"
+)
+
+const parallelism = 16
+
+// chunkSizeFor returns a chunk size for the given number of items to use for
+// parallel work. The size aims to produce good CPU utilization.
+func chunkSizeFor(n int) workqueue.Options {
+	s := int(math.Sqrt(float64(n)))
+	if r := n/parallelism + 1; s > r {
+		s = r
+	} else if s < 1 {
+		s = 1
+	}
+	return workqueue.WithChunkSize(s)
+}
+
+// Until is a wrapper around workqueue.ParallelizeUntil to use in scheduling algorithms.
+func Until(ctx context.Context, pieces int, doWorkPiece workqueue.DoWorkPieceFunc) {
+	workqueue.ParallelizeUntil(ctx, parallelism, pieces, doWorkPiece, chunkSizeFor(pieces))
+}

staging/src/k8s.io/client-go/go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/golang/groupcache v0.0.0-20160516000752-02826c3e7903
 	github.com/golang/protobuf v1.3.2
 	github.com/google/btree v1.0.0 // indirect
+	github.com/google/go-cmp v0.3.1
 	github.com/google/gofuzz v1.1.0
 	github.com/google/uuid v1.1.1
 	github.com/googleapis/gnostic v0.1.0

staging/src/k8s.io/client-go/util/workqueue/BUILD

@@ -13,6 +13,7 @@ go_test(
         "delaying_queue_test.go",
         "main_test.go",
         "metrics_test.go",
+        "parallelizer_test.go",
         "queue_test.go",
         "rate_limiting_queue_test.go",
     ],
@@ -20,6 +21,7 @@ go_test(
     deps = [
         "//staging/src/k8s.io/apimachinery/pkg/util/clock:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//vendor/github.com/google/go-cmp/cmp:go_default_library",
     ],
 )
 

staging/src/k8s.io/client-go/util/workqueue/parallelizer.go

@@ -25,39 +25,77 @@ import (
 
 type DoWorkPieceFunc func(piece int)
 
+type options struct {
+	chunkSize int
+}
+
+type Options func(*options)
+
+// WithChunkSize allows to set chunks of work items to the workers, rather than
+// processing one by one.
+// It is recommended to use this option if the number of pieces significantly
+// higher than the number of workers and the work done for each item is small.
+func WithChunkSize(c int) func(*options) {
+	return func(o *options) {
+		o.chunkSize = c
+	}
+}
+
 // ParallelizeUntil is a framework that allows for parallelizing N
 // independent pieces of work until done or the context is canceled.
-func ParallelizeUntil(ctx context.Context, workers, pieces int, doWorkPiece DoWorkPieceFunc) {
+func ParallelizeUntil(ctx context.Context, workers, pieces int, doWorkPiece DoWorkPieceFunc, opts ...Options) {
-	var stop <-chan struct{}
+	if pieces == 0 {
-	if ctx != nil {
+		return
-		stop = ctx.Done()
+	}
+	o := options{}
+	for _, opt := range opts {
+		opt(&o)
+	}
+	chunkSize := o.chunkSize
+	if chunkSize < 1 {
+		chunkSize = 1
 	}
 
-	toProcess := make(chan int, pieces)
+	chunks := ceilDiv(pieces, chunkSize)
-	for i := 0; i < pieces; i++ {
+	toProcess := make(chan int, chunks)
+	for i := 0; i < chunks; i++ {
 		toProcess <- i
 	}
 	close(toProcess)
 
-	if pieces < workers {
+	var stop <-chan struct{}
-		workers = pieces
+	if ctx != nil {
+		stop = ctx.Done()
+	}
+	if chunks < workers {
+		workers = chunks
 	}
-
 	wg := sync.WaitGroup{}
 	wg.Add(workers)
 	for i := 0; i < workers; i++ {
 		go func() {
 			defer utilruntime.HandleCrash()
 			defer wg.Done()
-			for piece := range toProcess {
+			for chunk := range toProcess {
-				select {
+				start := chunk * chunkSize
-				case <-stop:
+				end := start + chunkSize
-					return
+				if end > pieces {
-				default:
+					end = pieces
-					doWorkPiece(piece)
+				}
+				for p := start; p < end; p++ {
+					select {
+					case <-stop:
+						return
+					default:
+						doWorkPiece(p)
+					}
 				}
 			}
 		}()
 	}
 	wg.Wait()
 }
+
+func ceilDiv(a, b int) int {
+	return (a + b - 1) / b
+}

staging/src/k8s.io/client-go/util/workqueue/parallelizer_test.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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 workqueue
+
+import (
+	"context"
+	"fmt"
+	"sync/atomic"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type testCase struct {
+	pieces    int
+	workers   int
+	chunkSize int
+}
+
+func (c testCase) String() string {
+	return fmt.Sprintf("pieces:%d,workers:%d,chunkSize:%d", c.pieces, c.workers, c.chunkSize)
+}
+
+var cases = []testCase{
+	{
+		pieces:    1000,
+		workers:   10,
+		chunkSize: 1,
+	},
+	{
+		pieces:    1000,
+		workers:   10,
+		chunkSize: 10,
+	},
+	{
+		pieces:    1000,
+		workers:   10,
+		chunkSize: 100,
+	},
+	{
+		pieces:    999,
+		workers:   10,
+		chunkSize: 13,
+	},
+}
+
+func TestParallelizeUntil(t *testing.T) {
+	for _, tc := range cases {
+		t.Run(tc.String(), func(t *testing.T) {
+			seen := make([]int32, tc.pieces)
+			ctx := context.Background()
+			ParallelizeUntil(ctx, tc.workers, tc.pieces, func(p int) {
+				atomic.AddInt32(&seen[p], 1)
+			}, WithChunkSize(tc.chunkSize))
+
+			wantSeen := make([]int32, tc.pieces)
+			for i := 0; i < tc.pieces; i++ {
+				wantSeen[i] = 1
+			}
+			if diff := cmp.Diff(wantSeen, seen); diff != "" {
+				t.Errorf("bad number of visits (-want,+got):\n%s", diff)
+			}
+		})
+	}
+}
+
+func BenchmarkParallelizeUntil(b *testing.B) {
+	for _, tc := range cases {
+		b.Run(tc.String(), func(b *testing.B) {
+			ctx := context.Background()
+			isPrime := make([]bool, tc.pieces)
+			b.ResetTimer()
+			for c := 0; c < b.N; c++ {
+				ParallelizeUntil(ctx, tc.workers, tc.pieces, func(p int) {
+					isPrime[p] = calPrime(p)
+				}, WithChunkSize(tc.chunkSize))
+			}
+			b.StopTimer()
+			want := []bool{false, false, true, true, false, true, false, true, false, false, false, true}
+			if diff := cmp.Diff(want, isPrime[:len(want)]); diff != "" {
+				b.Errorf("miscalculated isPrime (-want,+got):\n%s", diff)
+			}
+		})
+	}
+}
+
+func calPrime(p int) bool {
+	if p <= 1 {
+		return false
+	}
+	for i := 2; i*i <= p; i++ {
+		if p%i == 0 {
+			return false
+		}
+	}
+	return true
+}

test/e2e/framework/.import-restrictions

@@ -187,6 +187,7 @@
 				"k8s.io/kubernetes/pkg/scheduler/framework/plugins/nodeports",
 				"k8s.io/kubernetes/pkg/scheduler/framework/plugins/noderesources",
 				"k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1",
+				"k8s.io/kubernetes/pkg/scheduler/internal/parallelize",
 				"k8s.io/kubernetes/pkg/scheduler/listers",
 				"k8s.io/kubernetes/pkg/scheduler/metrics",
 				"k8s.io/kubernetes/pkg/scheduler/nodeinfo",

test/integration/scheduler_perf/scheduler_bench_test.go

@@ -47,6 +47,7 @@ var (
 
 	defaultTests = []struct{ nodes, existingPods, minPods int }{
 		{nodes: 500, existingPods: 500, minPods: 1000},
+		{nodes: 600, existingPods: 10000, minPods: 1000},
 		{nodes: 5000, existingPods: 5000, minPods: 1000},
 	}
 	testNamespace  = "sched-test"