From owner-freebsd-hackers Sat Dec 4 9:37:16 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from feral.com (feral.com [192.67.166.1]) by hub.freebsd.org (Postfix) with ESMTP id CF0CF14D3F; Sat, 4 Dec 1999 09:37:08 -0800 (PST) (envelope-from mjacob@feral.com) Received: from semuta.feral.com (semuta [192.67.166.70]) by feral.com (8.8.7/8.8.7) with ESMTP id JAA10192; Sat, 4 Dec 1999 09:36:30 -0800 Date: Sat, 4 Dec 1999 09:36:30 -0800 (PST) From: Matthew Jacob Reply-To: mjacob@feral.com To: Mike Smith Cc: hackers@FreeBSD.ORG Subject: Re: tty level buffer overflows In-Reply-To: <199912040758.XAA00511@mass.cdrom.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Er, you should read the sio(4) manpage too. tty-level buffer overflows > have nothing to do with interrupt latency/execution time. You mean this: sio%d: tty-level buffer overflow. Problem in the application. Input has arrived faster than the given module could process it and some has been lost. Normally I might agree with this, but I use a tty line on a 150Mhz i386 to be a serial console for another freebsd box. This is a NS16550A with a 16 byte fifo. This systems is effectively idle except for this task. So, I'm running tip and I get constant tty-level buffer overflows at 9600 baud. I also have a 8 (well, 6 now since I moved and one of the system boards blew a backplane interface chip) 50 Mhz processor SS1000 running Solaris 2.6. It has 5 Zilog (2 byte fifo) 8530 chips running constant console sessions with regular large amounts of output (debugging and panicing other solaris systems for Fibre Channel work) via tip. There has never been a lost character that I can see except due to power outage. I am convinced to a moral certainty and beyond a reasonable doubt that if I had a single 50Mhz processor I'd have the same experience. Since the Solaris tip and the FreeBSD tip are essentially identical (both derive from BSD 4.X tip), I'd like to try and understand how this is an application problem :-). -matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message