Messages in this thread | | | Date | Sat, 14 Mar 1998 22:02:35 +0100 | From | Peter Endeborg <> | Subject | Serial problem => Slow PPP |
| |
In the newer kernels I have a realy bad PPP performance. And it is caused by some problems in the serial drivers, or interrupt handling.
pme@pescadero$ cat /proc/net/dev /proc/tty/driver/serial Inter-| Receive | Transmit face |bytes packets errs drop fifo frame|bytes packets errs drop fifo colls carrier multicast lo: 2704 43 0 0 0 0 2704 43 0 0 0 0 0 0 eth0: 0 67 0 0 0 0 0 60 0 0 0 0 0 0 sl0: 0 0 0 0 0 0 700 13 0 0 0 0 0 0 ppp0: 1493737 994 90 0 0 87 18605 936 0 0 0 0 0 0 serinfo:1.0 driver:4.24 0: uart:16450 port:3F8 irq:4 tx:0 rx:0 1: uart:16550A port:2F8 irq:3 tx:0 rx:0 2: uart:16550A port:3E8 irq:15 baud:9600 tx:0 rx:0 3: uart:16550A port:2E8 irq:7 baud:57600 tx:18651 rx:1694460 oe:216 RTS|CTS|DTR|DSR|CD
0.13 % of the characters are dropped. This causes a retrasmit timeout, and that gives a performance of about 1.8Kbyte/s on a line running at 48kbit/s, and 56700 on the serial link. (I got a lot more running MSWindos) I have tryed the 2.1.89 kernel with SMP and without SMP. I have also tryed to use a other UART, and changed the flowcontrol. Always the same speed. The machine is maybe not the most hot one today, but it have been running a lot better before. The CPU is a Pentium 120MHz. I have also tryed the unmaskirq on the disk. I do not help me at all.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu
| |