Check and correct host tuning at startup and on drift

main.go

@@ -329,11 +329,27 @@ func main() {
 		rcvbuf   = flag.Int("rcvbuf", 64<<20, "SO_RCVBUFFORCE per rx socket")
 		txCPUs   = flag.String("txcpus", "", "comma-separated CPUs to pin tx workers to")
 		rxCPUs   = flag.String("rxcpus", "", "comma-separated CPUs to pin rx workers to")
+		tune     = flag.Bool("tune", true, "check host settings at startup and correct them; without this they are only reported")
+		governor = flag.String("governor", "performance", "required cpufreq governor")
+		coalesce = flag.Uint("coalesce-usecs", 25, "required fixed rx/tx coalesce usecs, with adaptive coalescing off")
+		rxRing   = flag.Uint("rx-ring", 8160, "required rx ring size, clamped to hardware maximum")
+		txRing   = flag.Uint("tx-ring", 4096, "required tx ring size, clamped to hardware maximum")
+		setRings = flag.Bool("set-rings", true, "allow ring resizing at startup, which resets the link")
 	)
 	flag.Parse()
 
+	tcfg := tuneConfig{
+		enabled:  *tune,
+		governor: *governor,
+		rxUsecs:  uint32(*coalesce),
+		txUsecs:  uint32(*coalesce),
+		rxRing:   uint32(*rxRing),
+		txRing:   uint32(*txRing),
+		setRings: *setRings,
+	}
+
 	if err := run(*aName, *bName, *sizesArg, *patArg, *fanout, *txCPUs, *rxCPUs,
-		*duration, *interval, *drain, *txN, *rxN, *batch, *sndbuf, *rcvbuf, *verify, *duplex); err != nil {
+		*duration, *interval, *drain, *txN, *rxN, *batch, *sndbuf, *rcvbuf, *verify, *duplex, tcfg); err != nil {
 		fmt.Fprintln(os.Stderr, "error:", err)
 		os.Exit(1)
 	}
@@ -341,7 +357,7 @@ func main() {
 
 func run(aName, bName, sizesArg, patArg, fanout, txCPUsArg, rxCPUsArg string,
 	duration, interval, drain time.Duration, txN, rxN, batch, sndbuf, rcvbuf int,
-	verify, duplex bool) error {
+	verify, duplex bool, tcfg tuneConfig) error {
 
 	if aName == "" || bName == "" {
 		return fmt.Errorf("both -a and -b are required")
@@ -378,6 +394,19 @@ func run(aName, bName, sizesArg, patArg, fanout, txCPUsArg, rxCPUsArg string,
 		}
 	}
 
+	ifnames := []string{a.name, b.name}
+	fmt.Println("host settings:")
+	var fatal []string
+	for _, r := range applyTuning(tcfg, ifnames) {
+		fmt.Println(r)
+		if r.fatal {
+			fatal = append(fatal, r.item)
+		}
+	}
+	if len(fatal) > 0 {
+		return fmt.Errorf("cannot test with %s in this state", strings.Join(fatal, ", "))
+	}
+
 	cfg := config{
 		txWorkers: txN,
 		rxWorkers: rxN,
@@ -464,6 +493,9 @@ loop:
 		case now := <-tick.C:
 			secs := now.Sub(last).Seconds()
 			last = now
+			for _, w := range verifyTuning(tcfg, ifnames) {
+				fmt.Println(w)
+			}
 			for _, d := range dirs {
 				fmt.Println(d.reportInterval(secs))
 				if s := d.reportNIC(); s != "" {