Benchmark_Key-4 32955 36670 ns/op 109 B/op 0 allocs/op
Benchmark_Value-4 25776 47899 ns/op 140 B/op 0 allocs/op
It seems that by key requires is much better.
Also, it seems that the larger the size of the pod matters, I've tried with larger pods size and the results are worse for Value.
Most of the time is spent in runtime.duffcopy when iterating by value
| package main | |
| import ( | |
| "fmt" | |
| "math/rand" | |
| "testing" | |
| v1 "k8s.io/api/core/v1" | |
| metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" | |
| ) | |
| func generatePods(n int) map[int]v1.Pod { | |
| result := map[int]v1.Pod{} | |
| fakeData := RandStringRunes(10000) | |
| for i := 0; i < n; i++ { | |
| result[i] = v1.Pod{ | |
| ObjectMeta: metav1.ObjectMeta{ | |
| Name: fmt.Sprintf("pod%d", i), | |
| Namespace: "testns", | |
| }, | |
| Spec: v1.PodSpec{ | |
| Containers: []v1.Container{ | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| { | |
| Command: []string{"/bin/bash", "-c", "exec sleep 10000", fakeData}, | |
| Name: "hostexec", | |
| Image: "centos:7", | |
| ImagePullPolicy: v1.PullIfNotPresent, | |
| }, | |
| }, | |
| HostNetwork: true, | |
| }, | |
| } | |
| } | |
| return result | |
| } | |
| var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ") | |
| func RandStringRunes(n int) string { | |
| b := make([]rune, n) | |
| for i := range b { | |
| b[i] = letterRunes[rand.Intn(len(letterRunes))] | |
| } | |
| return string(b) | |
| } | |
| func IterateValue(pods map[int]v1.Pod) { | |
| found := false | |
| for _, pod := range pods { | |
| if pod.Name == "hola" { | |
| found = true | |
| } | |
| } | |
| if found { | |
| } | |
| } | |
| func IterateKey(pods map[int]v1.Pod) { | |
| found := false | |
| for i, _ := range pods { | |
| if pods[i].Name == "hola" { | |
| found = true | |
| } | |
| } | |
| if found { | |
| } | |
| } | |
| func Benchmark_Key(b *testing.B) { | |
| pods := generatePods(1000) | |
| for i := 0; i < b.N; i++ { | |
| IterateKey(pods) | |
| } | |
| } | |
| func Benchmark_Value(b *testing.B) { | |
| pods := generatePods(1000) | |
| for i := 0; i < b.N; i++ { | |
| IterateValue(pods) | |
| } | |
| } |
go test -benchmem -run=^$ -bench Benchmark_Key -cpuprofile profile_key.out . -v
goos: linux
goarch: amd64
pkg: k8s.io/kubernetes
cpu: AMD Ryzen 3 3200G with Radeon Vega Graphics
Benchmark_Key
Benchmark_Key-4 32955 36670 ns/op 109 B/op 0 allocs/op
PASS
ok k8s.io/kubernetes 1.515s
go test -benchmem -run=^$ -bench Benchmark_Value -cpuprofile profile_value.out . -v
goos: linux
goarch: amd64
pkg: k8s.io/kubernetes
cpu: AMD Ryzen 3 3200G with Radeon Vega Graphics
Benchmark_Value
Benchmark_Value-4 25776 47899 ns/op 140 B/op 0 allocs/op
PASS
ok k8s.io/kubernetes 1.934s
go tool pprof profile_key.out
File: kubernetes.test
Type: cpu
Time: Jun 17, 2021 at 9:56am (CEST)
Duration: 1.51s, Total samples = 1.41s (93.67%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 1.39s, 98.58% of 1.41s total
Showing top 10 nodes out of 30
flat flat% sum% cum cum%
0.49s 34.75% 34.75% 1.35s 95.74% k8s.io/kubernetes.IterateKey
0.37s 26.24% 60.99% 0.57s 40.43% runtime.mapaccess1
0.21s 14.89% 75.89% 0.29s 20.57% runtime.mapiternext
0.10s 7.09% 82.98% 0.10s 7.09% runtime.memequal64
0.08s 5.67% 88.65% 0.08s 5.67% runtime.memhash64
0.05s 3.55% 92.20% 0.05s 3.55% runtime.add (partial-inline)
0.04s 2.84% 95.04% 0.04s 2.84% runtime.isEmpty (inline)
0.03s 2.13% 97.16% 0.03s 2.13% runtime.suspendG
0.01s 0.71% 97.87% 0.01s 0.71% runtime.(*consistentHeapStats).acquire
0.01s 0.71% 98.58% 0.01s 0.71% runtime.bucketShift (inline)
go tool pprof profile_value.out
File: kubernetes.test
Type: cpu
Time: Jun 17, 2021 at 9:56am (CEST)
Duration: 1.92s, Total samples = 1.71s (88.98%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 1.71s, 100% of 1.71s total
Showing top 10 nodes out of 26
flat flat% sum% cum cum%
0.96s 56.14% 56.14% 0.96s 56.14% runtime.duffcopy
0.32s 18.71% 74.85% 1.67s 97.66% k8s.io/kubernetes.IterateValue
0.29s 16.96% 91.81% 0.39s 22.81% runtime.mapiternext
0.05s 2.92% 94.74% 0.05s 2.92% runtime.add (partial-inline)
0.03s 1.75% 96.49% 0.04s 2.34% runtime.(*bmap).overflow
0.02s 1.17% 97.66% 0.02s 1.17% runtime.isEmpty (inline)
0.01s 0.58% 98.25% 1.69s 98.83% k8s.io/kubernetes.Benchmark_Value
0.01s 0.58% 98.83% 0.01s 0.58% runtime.(*mheap).freeMSpanLocked
0.01s 0.58% 99.42% 0.01s 0.58% runtime.mallocgc
0.01s 0.58% 100% 0.01s 0.58% runtime.markrootSpans