From owner-freebsd-current Wed Nov 13 08:06:17 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id IAA25512 for current-outgoing; Wed, 13 Nov 1996 08:06:17 -0800 (PST) Received: from freefall.freebsd.org (localhost.cdrom.com [127.0.0.1]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id IAA25507; Wed, 13 Nov 1996 08:06:12 -0800 (PST) Message-Id: <199611131606.IAA25507@freefall.freebsd.org> To: "=?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?=" (Andrey A. Chernov) cc: current@freebsd.org, scsi@freebsd.org Subject: Re: SCB paging is most dangerous option now! In-reply-to: Your message of "Wed, 13 Nov 1996 18:34:25 +0300." <199611131534.SAA00239@nagual.ru> Date: Wed, 13 Nov 1996 08:06:10 -0800 From: "Justin T. Gibbs" Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >I read only mode I got the almost same result with SCB paging as without it. >This bug affects _writing_only_, not reading. >And I can't start 8 dds for each drive in both modes, >3 dds per drive is enough to cause "Queue Full" in both modes, but >it is harmless due to read only. This is probably what is causing your corruption in the SCB Paging case. Which drive can only do 3 transactions at a time? I'm sure that your IBM can do more. It may very well be that one of your drives doesn't like the fact that the code with SCB paging turned on will basically continually pound on that drive, causing queue full conditions, until there aren't enough transactions queued to make this happen any more. The patch I posted for Andreas' problem may help in this regard. As for your problem happening on the "first write", are you sure this isn't the "first sync" after boot?? >If I increase dds count, I got "timed out in dataout phase" for SCB mode or >"timed out in message out phase" for non-SCB mode. That dataout phase one could actually be "while idle". I just found a bug in the diagnostic code that reports that. Hmmm. >-- >Andrey A. Chernov > >http://www.nagual.ru/~ache/ -- Justin T. Gibbs =========================================== FreeBSD: Turning PCs into workstations ===========================================