> This is a complete pointless test. Use a bog standard 8250 UART on the > PC and connect a microcontroller on the other end which serves you an > continous stream of data at 115200 Baud. > > There is no way you can keep up with that without the low latency > option neither on old and nor on new machines if you have enough other > stuff going on in the system. Sorry but having done this in the past the reverse is true. On ancient machines with crap uarts the low_latency case would routinely overrun while the non low_latency case did not. That was half of the point of deferred processing - it pushed tty processing out of the IRQ handler so bytes were not lost and a 486DX could cope with a 56Kbit modem. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html