bench/perf: perf script nop sq entry

Signed-off-by: Nugraha <richiisei@gmail.com>

bench/perf/main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime"
+	"runtime/pprof"
+	"syscall"
+	"time"
+
+	"github.com/ii64/gouring"
+)
+
+// usage: go tool pprof -http=:9001 pprof.cpu
+
+var fs = flag.NewFlagSet("perf", flag.ExitOnError)
+
+var (
+	entries      uint
+	sqPoll       bool
+	sqThreadCpu  uint
+	sqThreadIdle uint
+
+	N    uint
+	noti uint
+)
+
+func init() {
+	fs.UintVar(&entries, "entries", 256, "Entries")
+	fs.BoolVar(&sqPoll, "sqpoll", false, "Enable SQPOLL")
+	fs.UintVar(&sqThreadCpu, "sqthreadcpu", 4, "SQ Thread CPU")
+	fs.UintVar(&sqThreadIdle, "sqthreadidle", 10_000, "SQ Thread idle")
+
+	fs.UintVar(&N, "n", 10_000, "N times")
+	fs.UintVar(&noti, "noti", 10_000, "Notify per attempt N")
+}
+
+func main() {
+	err := fs.Parse(os.Args[1:])
+	if err != nil {
+		panic(err)
+	}
+
+	// check entries size
+	if entries > uint(^uint32(0)) {
+		panic("entries overflow.")
+	}
+
+	params := &gouring.IoUringParams{}
+	if sqPoll {
+		params.Flags |= gouring.IORING_SETUP_SQPOLL
+		params.SqThreadCpu = uint32(sqThreadCpu)
+		params.SqThreadIdle = uint32(sqThreadIdle)
+	}
+
+	h, err := gouring.NewWithParams(uint32(entries), params)
+	if err != nil {
+		panic(err)
+	}
+	defer h.Close()
+
+	f, err := os.Create("pprof.cpu")
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("performing...")
+
+	pprof.StartCPUProfile(f)
+	defer pprof.StopCPUProfile()
+
+	var i, j uint
+	var sqe *gouring.IoUringSqe
+	var cqe *gouring.IoUringCqe
+	var submitted int
+
+	startTime := time.Now()
+	for i = 0; i < N; i++ {
+		if i%noti == 0 { // notify
+			fmt.Printf("n:%d e:%s\n", j, time.Now().Sub(startTime))
+		}
+
+		for j = 0; j < entries; j++ {
+			sqe = h.GetSQE()
+			if sqe == nil { // spinning wait...
+				runtime.Gosched()
+				continue
+			}
+			gouring.PrepNop(sqe)
+			sqe.UserData = uint64(i + j)
+		}
+		submitted, err = h.Submit()
+		if err != nil {
+			panic(err)
+		}
+
+		if i%noti == 0 { // notify
+			fmt.Printf(" >> submitted %d\n", submitted)
+		}
+
+		for j = 0; j < entries; j++ {
+			err = h.WaitCQE(&cqe)
+			if err != nil {
+				panic(err)
+			}
+			if cqe == nil {
+				panic("cqe is nil!")
+			}
+			if cqe.Res < 0 {
+				panic(syscall.Errno(-cqe.Res))
+			}
+			_ = cqe
+		}
+	}
+	_ = submitted
+	_ = err
+}