From owner-freebsd-questions Sat Oct 11 17:05:12 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id RAA18124 for questions-outgoing; Sat, 11 Oct 1997 17:05:12 -0700 (PDT) (envelope-from owner-freebsd-questions) Received: from freebie.lemis.com (gregl1.lnk.telstra.net [139.130.136.133]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id RAA18117 for ; Sat, 11 Oct 1997 17:05:05 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: (from grog@localhost) by freebie.lemis.com (8.8.7/8.8.5) id JAA07404; Sun, 12 Oct 1997 09:34:54 +0930 (CST) Message-ID: <19971012093454.31985@lemis.com> Date: Sun, 12 Oct 1997 09:34:54 +0930 From: Greg Lehey To: parrothd@midwest.net Cc: freebsd-questions@FreeBSD.ORG Subject: Re: tty-level buffer overflows References: <3.0.3.32.19971001225109.006e88f0@midwest.net> <19971002142420.49578@lemis.com> <3433AF01.1578@midwest.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.84e In-Reply-To: <3433AF01.1578@midwest.net>; from bla bla on Thu, Oct 02, 1997 at 09:26:09AM -0500 Organisation: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8250 Fax: +61-8-8388-8250 Mobile: +61-41-739-7062 WWW-Home-Page: http://www.lemis.com/~grog Fight-Spam-Now: http://www.cauce.org Sender: owner-freebsd-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk 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. Greg