From owner-freebsd-current Fri Aug 8 17:24:26 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id RAA25446 for current-outgoing; Fri, 8 Aug 1997 17:24:26 -0700 (PDT) Received: from zippy.dyn.ml.org (garbanzo@sfmax4-221.ppp.wenet.net [206.169.224.221]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id RAA25431 for ; Fri, 8 Aug 1997 17:24:20 -0700 (PDT) Received: from localhost (garbanzo@localhost) by zippy.dyn.ml.org (8.8.7/8.8.7) with SMTP id RAA07511; Fri, 8 Aug 1997 17:24:10 -0700 (PDT) X-Authentication-Warning: zippy.dyn.ml.org: garbanzo owned process doing -bs Date: Fri, 8 Aug 1997 17:24:08 -0700 (PDT) From: Alex X-Sender: garbanzo@zippy.dyn.ml.org To: Tom cc: "John W. DeBoskey" , freebsd-current@FreeBSD.ORG Subject: Re: scsi time-out & lockup under smp In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Fri, 8 Aug 1997, Tom wrote: > > This is a fairly well known problem with the 2940U/UW, and probably > > anything else based on the 7880. All I can say is that for heavy disk io, > > don't use that controller, two controllers might be causing some of those > > problems too. However I'd also suggest that you take the number of busses > > down a notch, unless you have devices on bus 255, and that you cvsup the > > most recent FreeBSD sources,as I think some improvments have been made to > > this driver, and many improvments have been made to the smp code. > > > > - alex > > Well known problem? I've never seen it, even with heavy io on a 3940UW. > I use AHC_TAGENABLE, but NOT AHC_SCBPAGING. I use both with no problems on an aic-7880 (2940UW). However I've seen many reports of people having problems with the 2940U/UW doing this sort of thing under _continuous heavy_ io. However there's a really great explaination of what scb paging is in the aic7xxx driver. Stuff like that deserves a place in either a.) the man pages or b.) the texinfo database (or whatever it's called). > I don't believe that any changes have been made to the ahc driver > lately. True. > I think this problem is device dependant. Certain devices will seize > the bus, and driver is unable to get it back. - alex