Date: Wed, 15 Oct 1997 00:19:14 -0500 (CDT) From: "Matthew D. Fuller" <fullermd@futuresouth.com> To: Greg Lehey <grog@lemis.com> Cc: parrothd@midwest.net, freebsd-questions@FreeBSD.ORG Subject: Re: tty-level buffer overflows Message-ID: <Pine.BSF.3.96.971015001645.27275E-100000@shell.futuresouth.com> In-Reply-To: <19971012093454.31985@lemis.com>
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On Sun, 12 Oct 1997, Greg Lehey wrote: > On Thu, Oct 02, 1997 at 09:26:09AM -0500, bla bla wrote: > > Greg Lehey wrote: > >> > >> On Wed, Oct 01, 1997 at 10:51:09PM -0500, Jonathan E. Lyons wrote: > >>> Is this anything to be concerned about? I've got an X2 modem, with the port > >>> speed set at 57600..... > >>> > >>> > >>> Sep 28 16:42:11 cplkagan /kernel: sio0: 660 more tty-level buffer overflows > >>> (total 660) > >>> Sep 29 13:52:41 cplkagan /kernel: pid 18534 (ping), uid 0: exited on signal 3 > >>> Sep 30 21:05:02 cplkagan /kernel: sio0: 100 more tty-level buffer overflows > >>> (total 760) > >>> Sep 30 22:00:02 cplkagan /kernel: sio0: 198 more tty-level buffer overflows > >>> (total 958) > >>> Sep 30 22:05:01 cplkagan /kernel: sio0: 199 more tty-level buffer overflows > >>> (total 1157) > >>> Sep 30 22:05:02 cplkagan /kernel: sio0: 1076 more tty-level buffer > >>> overflows (total 2233) > >>> Oct 1 05:30:02 cplkagan /kernel: sio0: 940 more tty-level buffer overflows > >>> (total 3173) > >> > >> Yes. With PPP, each of these means a lost packet, which is expensive. > >> This shouldn't happen. Is the machine slow or heavily loaded? > >> Otherwise you might be losing interrupts. > >> > >> Greg > > > > Depends on your version of slow,:), it's a 486/66 8megs of ram, running > > ppp -alias, for a small house LAN. It does however has other processes > > running, but whenever I do a top -s 1 about %90 of the machine is idle, > > until someone starts to dl, or hits the Web server from the local LAN. > > Could it be the serial ports itself? The board it self has one built-in > > serial port, but I didn't think it could handle the speed(it's an old > > Packard Hell MB) so I threw in a multi I/O card, trying to avoid serial > > problems... > > The CPU has enough power, but with 8 MB you're going to be doing a lot > of swapping, during which I think the async interrupts are locked out. > I'd consider this fits my description of "heavily loaded", even if the > CPU is 90% idle. This could be your problem. I had a problem with overflows. I have a 28.8 modem, and if I set the port speed to 115200, I get overflows over-flowing on my xconsole. But only on incoming packets, which would seem to me to be the opposite of what you'd expect. If I set it to 28800, no problems. If I set it to 14400, no problems. I know it's not my system that's slow; Cyrix 6x86 166, 72 megs RAM, the serial ports are both 16550. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* | FreeBSD; the way computers were meant to be | * "The only reason I'm burning my candle at both ends, is * | that I haven't figured out how to light the middle yet."| * fullermd@futuresouth.com :-} MAtthew Fuller * | http://keystone.westminster.edu/~fullermd | *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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