Jumbo in the size mix (MTU 9000 + module jumbo pinned), check-first module config trusting GET reads, cable diag async at startup through the reset path, MODULES table dissolved into SETTINGS/LINKS, per-driver NIC counter sets, comment cleanup

main.go

@@ -488,8 +488,8 @@ const (
 )
 
 // The mac appends the fcs, so 60 and 1514 here are the smallest and largest
-// standard frames, 64 and 1518 on the wire.
-var frameSizes = []int{60, 128, 256, 512, 1024, 1280, 1514}
+// standard frames, 64 and 1518 on the wire; 9014 fills the 9000 MTU.
+var frameSizes = []int{60, 128, 256, 512, 1024, 1280, 1514, 9014}
 
 func main() {
 	// Left empty, the test pair is found by driver name instead: as PID 1 there
@@ -576,13 +576,6 @@ func run(aName, bName string) (err error) {
 		return err
 	}
 	defer noise.close()
-	for _, e := range []endpoint{a, b} {
-		for _, s := range frameSizes {
-			if s > e.mtu+ethHdrLen {
-				return fmt.Errorf("size %d exceeds %s MTU %d (max frame %d)", s, e.name, e.mtu, e.mtu+ethHdrLen)
-			}
-		}
-	}
 
 	a.tag, b.tag = "TEST A", "TEST B"
 	noise.eps[0].tag, noise.eps[1].tag = "NOISE A", "NOISE B"
@@ -593,16 +586,34 @@ func run(aName, bName string) (err error) {
 		ethertypes[i] = uint16(etherBase + i)
 	}
 
-	if err := reportChecks("HOST SETTINGS",
-		append(configureSystem(ifnames, ethertypes), configureNoise(noise.names())...)); err != nil {
+	modules, moduleIDs, err := openModules([2]string{a.name, b.name})
+	if err != nil {
 		return err
 	}
 
-	modules, cable, moduleChecks := moduleBringup([2]string{a.name, b.name})
-	if err := reportChecks("MODULES", moduleChecks); err != nil {
+	checks := configureSystem(ifnames, ethertypes)
+	checks = append(checks, moduleChecks(modules, [2]string{a.name, b.name})...)
+	checks = append(checks, configureNoise(noise.names())...)
+	if err := reportChecks("SETTINGS", checks); err != nil {
 		return err
 	}
-	diag := newCableDiag(modules, cable)
+
+	// The MTU check may have just raised them, so both are re-read before the
+	// frame sizes are judged.
+	for _, e := range []*endpoint{&a, &b} {
+		fresh, err := lookupEndpoint(e.name)
+		if err != nil {
+			return err
+		}
+		e.mtu = fresh.mtu
+		for _, s := range frameSizes {
+			if s > e.mtu+ethHdrLen {
+				return fmt.Errorf("size %d exceeds %s MTU %d (max frame %d)", s, e.name, e.mtu, e.mtu+ethHdrLen)
+			}
+		}
+	}
+
+	diag := newCableDiag(modules, cableInfo{})
 
 	var dirs []*direction
 	for _, p := range [][2]endpoint{{a, b}, {b, a}} {
@@ -619,14 +630,18 @@ func run(aName, bName string) (err error) {
 	}()
 
 	var linkRows [][]string
-	for _, e := range []endpoint{a, b, noise.eps[0], noise.eps[1]} {
+	for i, e := range []endpoint{a, b, noise.eps[0], noise.eps[1]} {
+		mod := ""
+		if i < len(moduleIDs) {
+			mod = moduleIDs[i]
+		}
 		linkRows = append(linkRows, []string{
-			paint(e.tag, cCyan), e.name, e.macString(), fmt.Sprintf("%d", e.mtu),
+			paint(e.tag, cCyan), e.name, e.macString(), fmt.Sprintf("%d", e.mtu), mod,
 		})
 	}
 	fmt.Println(renderBox("LINKS",
-		[]string{"TAG", "INTERFACE", "MAC", "MTU"},
-		[]bool{false, false, false, true}, linkRows))
+		[]string{"TAG", "INTERFACE", "MAC", "MTU", "MODULE"},
+		[]bool{false, false, false, true, false}, linkRows))
 	fmt.Println()
 
 	// One row carries both directions, so line rate is both links at once.
@@ -657,8 +672,6 @@ func run(aName, bName string) (err error) {
 		defer holdPanic()
 		noise.run(&done)
 	}()
-	// Also ungated: SNR and temperature ride the module's own management bus,
-	// not the wire being measured.
 	for _, m := range modules {
 		wg.Add(1)
 		go func() {
@@ -716,6 +729,9 @@ func run(aName, bName string) (err error) {
 
 	start := time.Now()
 	close(startTx)
+	// The first measure rides the same async path as a reset, so startup never
+	// waits on it; counters re-baseline when its link blip is over.
+	diag.kick(&done)
 	tick := time.NewTicker(reportInterval)
 	defer tick.Stop()
 
@@ -728,14 +744,15 @@ func run(aName, bName string) (err error) {
 			return fmt.Errorf("%v", p)
 		case <-sig:
 			return nil
-		// A reset re-measures the cable first — the cable under a reset is
-		// usually a new one — and the counters re-baseline when the diag's own
-		// link blip is over, so it is never charged to the fresh run.
+		// A reset re-measures the cable first; the counters re-baseline at diag
+		// completion, so its link blip is never charged to the fresh run.
 		case <-space:
 			if diag.kick(&done) {
 				fmt.Println(stats.rule("measuring cable"))
 			}
 		case <-diag.completed:
+			info, _ := diag.snapshot()
+			fmt.Println(stats.rule("cable diag: " + cableLine(info)))
 			start = resetAll(dirs, modules, stats)
 		case <-disp.fb.flips:
 			now := time.Now()