From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH] Stop using num_physpages in aacraid Date: Fri, 09 May 2008 09:28:57 -0500 Message-ID: <1210343337.3069.9.camel@localhost.localdomain> References: <20080502185227.GN14976@parisc-linux.org> <20080503105135.GY14976@parisc-linux.org> <1210281511.3114.72.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:48423 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089AbYEIO3B (ORCPT ); Fri, 9 May 2008 10:29:01 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Mark Salyzyn Cc: Matthew Wilcox , "linux-scsi@vger.kernel.org" On Fri, 2008-05-09 at 02:39 -0400, Mark Salyzyn wrote: > ACK > > with comment, I had chosen to perform the sizeof check as it optimized > out the code on the 32 bit platforms and could have merged the > aac_scsi_32_64 and aac_scsi_32 functions (such considerations are my > penance for writing peephole optimizers and BIOS code in C/C++). Never > sacrifice clarity/maintainability for optimization if you can afford it. Yes ... I wish there were some way of getting the dma_get_required_mask() > DMA_32BIT_MASK to compile out in the 32 bit case. I'll think about it. Another thing to note is that your problem could be solved if we could adjust the queue mask per device (you want a 64 bit mask for the raid devices and a 32 bit one for the physical ones). This is analagous to the ATA MDMA problem with ATA/ATAPI (the protocol can only do 32 bits with ATAPI but the full 64 bits with ATA). I'll see if we can use this as a case to drive a fix for that. James