>I'm running macbsd on a IIcx with 8mb RAM, and 20 mb of swap, using the
>WORMHOLE
>kernel. Every so often, I seem to get ring buffer overrun errors. These don't
>occur extremely often, or seem to cause any major problem, but they are
>slightly
>disconcerting nonetheless. The errors seem to occur irregardless of load or the
>number of users online. Is this anything to worry about? If so, what can I
>do to
>fix the problem? Thanks for any help anyone can offer.
>
>Sincerely,
>
>
>
>Daniel Bell

I used to get this problem a lot on my Mac IIx, especially when I used both
serial ports simultaneously (one ppp line to another machine, another to my
modem and out to the world beyond...)

The problem lessened when I switched the ppp scripts to 38400 baud, rather
than 57600.  (I've been told by others in this list that the 57600 rate
REALLY bogs down the kernel, so it spends more time receiving data than it
does processing it and sending it on to wherever its supposed to go.)

I later made the following changes to my kernel sources, and haven't seen
the problem since:

In /usr/src/sys/arch/mac68k/dev/zsvar.h, change the following lines:
#define ZLRB_RING_SIZE 512              /* ZS line ring buffer size */
#define ZLRB_RING_MASK 511              /* mask for same */

to:
#define ZLRB_RING_SIZE 1024             /* ZS line ring buffer size */
#define ZLRB_RING_MASK 1023             /* mask for same */

This fix was mailed to me by Bill Studenmund, and he explained that they
have the effect of increasing the ring buffer's size.

Hope this helps you!

Aaron


--
Aaron Scott Magill                                             amagill@uiuc.edu
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