From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: Bugs on Linux 2.6.18-rc2 sg code? Date: Sun, 20 Aug 2006 10:01:10 +0100 Message-ID: <20060820090110.GA18927@flint.arm.linux.org.uk> References: <8202f4270608101843r7df002d2l40e03eca3271b050@mail.gmail.com> <44E6388D.1000206@torque.net> <44E68F76.4010702@torque.net> <8202f4270608200051p688f4654ub6aecb604e0152f1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([217.147.92.249]:58642 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1751702AbWHTJBV (ORCPT ); Sun, 20 Aug 2006 05:01:21 -0400 Content-Disposition: inline In-Reply-To: <8202f4270608200051p688f4654ub6aecb604e0152f1@mail.gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Fajun Chen Cc: dougg@torque.net, linux-scsi@vger.kernel.org, akpm@osdl.org On Sun, Aug 20, 2006 at 01:51:33AM -0600, Fajun Chen wrote: > I've tested mmap code in both 2.6.15.4 and 2.6.18-rc2 with > sg_vma_nopage() from 2.6.15.4, this particular sg mmap bug seems to be > fixed?$B!%!!#S#i#n#c#e!!#y#o#u#r!!#p#a#t#c#h!!#f#o#r!!#2!%#6!%#1#8!]#r#c#4!!#i#s!!essentially not different This is unreadable... > from 2.6.15.4 (the only difference is sg->offset, which is always 0 > for sg mmap or indirect IO), this should fix the problem. I'll test > your patch next week to confirm it anyway. > > I would like to also report a potential cache coherency issue on sg > when running on some processors other than i386. I ran into cache > coherency issue on ARM XScale Iop80321. I no longer touch SCSI, partly because the only SCSI based systems I have are extremely (10 years) old now. All my SCSI knowledge is based on ancient 2.4 code and is no longer relevant. > Existing sg code for direct IO: I don't think direct-IO has ever been tested and debugged on ARM either. I wouldn't know where to start with direct-IO - never used and never looked at it. And more importantly (for me), I'd rather not get into another squabble with James over cache coherency ideas, so I want to stay well away from cache coherency and block devices, thanks. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core