From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mta02-svc.ntlworld.com (mta02-svc.ntlworld.com [62.253.162.42]) by dsl2.external.hp.com (Postfix) with ESMTP id E111A4852 for ; Sat, 21 Feb 2004 00:58:48 -0700 (MST) Received: from calypso ([62.254.21.7]) by mta02-svc.ntlworld.com (InterMail vM.4.01.03.37 201-229-121-137-20020806) with ESMTP id <20040221075816.UQTH14417.mta02-svc.ntlworld.com@calypso> for ; Sat, 21 Feb 2004 07:58:16 +0000 Received: from sdb by calypso with local (Exim 3.36 #1 (Debian)) id 1AuS2D-0001H5-00 for ; Sat, 21 Feb 2004 07:58:49 +0000 Date: Sat, 21 Feb 2004 07:58:49 +0000 From: Stuart Brady To: parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] Hanging with kernels >= 2.4.22 Message-ID: <20040221075849.GA1642@calypso> References: <20040218235225.GA1623@calypso> <20040219062907.GC13916@colo.lackof.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20040219062907.GC13916@colo.lackof.org> Sender: Stuart Brady List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Feb 18, 2004 at 11:29:07PM -0700, Grant Grundler wrote: > On Wed, Feb 18, 2004 at 11:52:25PM +0000, Stuart Brady wrote: > > I'm having problems with kernels >= 2.4.22 on a 715/100. > > Stuart, > All your symptoms point at disk IO hanging. > Setting the default queue depth to 1 would be worth trying. > I've forgotten the details for setting queue depth. > > search parisc-linux mailing list archives "scsi queue tags". > http://lists.parisc-linux.org/pipermail/parisc-linux/2004-January/022087.html Thanks! Changing NCR_700_MAX_TAGS to 1 in drivers/scsi/53c700.h did the trick. Will I now have poor disk performance? If so, might I get away with setting it to something higher, like 2 or 4, maybe? I've not heard of tagged command queues before - the idea seems to be to transfer data to the drive as early as possible, but make decisions as to what should be written first at a later stage. Is that correct? http://lists.parisc-linux.org/pipermail/parisc-linux/2002-February/015465.html says that no tagged queue is a bad thing. Why is that? > btw, 715/50 is NOT the same as 715/100. > 715/100 should have "coherent" DMA and 715/50 does not. > > Maybe a FAQ entry for "715/xxx hangs" could be your first contribution? That's a good idea. Where should I send the entry? Here? -- Stuart Brady