From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [PATCH] sg driver for large page_size, lk 2.6.18 Date: Fri, 22 Sep 2006 16:23:00 -0500 Message-ID: <45145434.4080007@us.ibm.com> References: <4511BEC1.8030809@torque.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:53477 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S932177AbWIVVXO (ORCPT ); Fri, 22 Sep 2006 17:23:14 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e32.co.us.ibm.com (8.13.8/8.12.11) with ESMTP id k8MLN5PD021048 for ; Fri, 22 Sep 2006 17:23:05 -0400 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by westrelay02.boulder.ibm.com (8.13.6/8.13.6/NCO v8.1.1) with ESMTP id k8MLN5Vb375114 for ; Fri, 22 Sep 2006 15:23:05 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id k8MLN5h5007567 for ; Fri, 22 Sep 2006 15:23:05 -0600 In-Reply-To: <4511BEC1.8030809@torque.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dougg@torque.net Cc: linux-scsi@vger.kernel.org, david.falkinder@hp.com Douglas Gilbert wrote: > This sg driver patch addresses the problem with larger > page sizes reported by Brian King in this post: > http://marc.theaimsgroup.com/?l=linux-scsi&m=115867718623631&w=2 This fixes the oops I was seeing on PPC64 with 64k pages enabled. Brian > Some other related matters are also addressed. Some of these > prevent oopses when the SG_SCATTER_SZ or scatter_elem_sz are > set to inappropriate values. > > The scatter_elem_sz has been tested up to 4 MB which should > make the largest data transfer with one SCSI command, 32 MB > less one block, achievable with a relatively small number > of elements in the scatter gather list. > > For consideration in lk 2.6.19 . The patch is against lk 2.6.18 . > > ChangeLog: > - add scatter_elem_sz boot time parameter and sysfs module > parameter that is initialized to SG_SCATTER_SZ > - the driver will then adjust scatter_elem_sz to be the > max(given(scatter_elem_sz), PAGE_SIZE) > It will also round it up, if necessary, to be a power > of two > - clean up sg.h header, correct bad urls and some statements > that are no longer valid > - make the def_reserved_size sysfs module attribute writable > > Signed-off-by: Douglas Gilbert > > Doug Gilbert > -- Brian King eServer Storage I/O IBM Linux Technology Center