Fail loudly on a touch read, stop the workers before their sockets close, and file down the small edges

render.go

@@ -75,8 +75,10 @@ func commas(v uint64) string {
 // on the label. Below a thousand no letter is left dangling, since a trailing
 // space would push the figure off centre.
 func scaleSI(v float64) string {
+	// %.2f rounds 999.995 and up to a fourth digit, so the magnitude rolls over
+	// where the rounding does rather than at the bare thousand.
 	for _, mag := range []string{"", "k", "M", "G", "T"} {
-		if v < 1000 {
+		if v < 999.995 {
 			if mag == "" {
 				return fmt.Sprintf("%.2f", v)
 			}