From owner-freebsd-questions Tue Apr 21 12:04:45 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA20126 for freebsd-questions-outgoing; Tue, 21 Apr 1998 12:04:45 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from gdi.uoregon.edu (gdi.uoregon.edu [128.223.170.30]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA20006 for ; Tue, 21 Apr 1998 19:04:19 GMT (envelope-from dwhite@gdi.uoregon.edu) Received: from localhost (dwhite@localhost) by gdi.uoregon.edu (8.8.7/8.8.8) with SMTP id MAA04221; Tue, 21 Apr 1998 12:04:09 -0700 (PDT) (envelope-from dwhite@gdi.uoregon.edu) Date: Tue, 21 Apr 1998 12:04:09 -0700 (PDT) From: Doug White Reply-To: Doug White To: Steve Sims cc: freebsd-questions@FreeBSD.ORG Subject: Re: SILO Overflows In-Reply-To: <000301bd6d21$cd6c0a00$64468094@Elvis.RatsNest.VaBeach.Va.Us> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 21 Apr 1998, Steve Sims wrote: > Last week I installed a 56K/x2 USR Courier V.Everything internal modem in my > puny 486/66 and have been seeing repeated "x more silo overflow (n total)" > messages whenever the CPU gets even *slightly* loaded up. I need the whole message here-- you left off the important part. There are two classes of these: x more interrupt-level silo overflows x more tty-level silo overflows These point to problems with the kernel getting the data fast enough and a user process getting the data fast enough, respectively. > True Confession: I took a couple of stabs at tweaking sio.c to set the fifo > threshold lower, but after a while it dawned on me that tweaking the > tx_fifo_size setting was NEVER going to help receive errors, so I gave up. > D'oh! You actually can tune the tx/rx buffer size. You have a 16 byte buffer on the 16550 and you can define the split between tx and rx. So shrinking tx will increase the rx and vice versa. BTW, you *do* have a 16550 UART in there, right? Your dmesg should report: sio0 at 0x3f8-0x3ff irq 4 on isa sio0: type 16550A Doug White | University of Oregon Internet: dwhite@resnet.uoregon.edu | Residence Networking Assistant http://gladstone.uoregon.edu/~dwhite | Computer Science Major To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message