Max active spinning ns/op in go runtime 1.6

max_spin_test.go

// proc_test.s

#include "go_asm.h"
#include "go_tls.h"
#include "funcdata.h"
#include "textflag.h"

TEXT runtime·ProcYield(SB),NOSPLIT,$0-0
	MOVL	cycles+0(FP), AX
again:
	PAUSE
	SUBL	$1, AX
	JNZ	again
	RET
	
// proc.go
package runtime

func ProcYield(cycles uint32)
	
// proc_test.go
package runtime_test

const (
	active_spin     = 4
	active_spin_cnt = 30
	passive_spin    = 1
)

func MaxSpin() {
	for i := 0; i < active_spin; i ++ {
		runtime.ProcYield(active_spin_cnt)
	}
}

func BenchmarkMaxSpin(b *testing.B) {
	for i := 0; i < b.N; i ++ {
		MaxSpin()
	}
}

// Results
// go test -run ! -bench MaxSpin . -v

BenchmarkMaxSpin-8       3000000               420 ns/op