Re: 2.0.30 serial.c, ppp.c and pppd-2.2 questions

Rogier Wolff (
Thu, 24 Jul 1997 09:13:02 +0200 (MET DST) wrote:
> Theodore Y. Ts'o:
> : Date: Wed, 23 Jul 1997 08:07:23 +0200 (MET DST)
> : From: (Rogier Wolff)
> : Yes, I agree. At 38k4 you need 130 ms to fill the flip buffer. And if
> : you see this kind of delays there is something "wrong". An easy
> : solution like increasing the buffer size may delay the fenomenon to
> : the point that it is hard to reproduce, but we haven't really fixed
> : anything. In some cases not receiving any chars for 130 ms can be
> : annoying too....
> : And at 115kbaud you need 44ms to fill the flip buffer. So you'd have to
> : miss 4 clock ticks before the flip buffer would be overflowing. I can
> : believe we're missing 1, or maybe even 2, but 4?
> Possibly entirely unrelated (you are talking about missed timer interrupts,
> probably I am talking about missed serial line interrupts) but

Andries, Are you seeing messages mentioning the flip buffer?

Some time ago, I was still running xntpd on my router, and back then I
was pretty sure that no actual (timer) interrupts were lost. A 10 ms
jump would show up in the xntp graphs that I would make occasionally
back then.