From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030811AbbJ3Vfy (ORCPT ); Fri, 30 Oct 2015 17:35:54 -0400 Received: from e17.ny.us.ibm.com ([129.33.205.207]:49581 "EHLO e17.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030701AbbJ3Vfw (ORCPT ); Fri, 30 Oct 2015 17:35:52 -0400 X-IBM-Helo: d01dlp03.pok.ibm.com X-IBM-MailFrom: nacc@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;sparclinux@vger.kernel.org Date: Fri, 30 Oct 2015 14:35:46 -0700 From: Nishanth Aravamudan To: David Miller Cc: hch@infradead.org, keith.busch@intel.com, aik@ozlabs.ru, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, paulus@samba.org, sparclinux@vger.kernel.org, willy@linux.intel.com, linuxppc-dev@lists.ozlabs.org, david@gibson.dropbear.id.au Subject: Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA Message-ID: <20151030213546.GL7716@linux.vnet.ibm.com> References: <20151028135922.GA27909@localhost.localdomain> <20151029115536.GA28090@infradead.org> <20151029155701.GJ7716@linux.vnet.ibm.com> <20151029.184955.728736673434401711.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151029.184955.728736673434401711.davem@davemloft.net> X-Operating-System: Linux 3.13.0-40-generic (x86_64) User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15103021-0041-0000-0000-0000021E8FBA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29.10.2015 [18:49:55 -0700], David Miller wrote: > From: Nishanth Aravamudan > Date: Thu, 29 Oct 2015 08:57:01 -0700 > > > So, would that imply changing just the NVMe driver code rather than > > adding the dma_page_shift API at all? What about > > architectures that can support the larger page sizes? There is an > > implied performance impact, at least, of shifting the IO size down. > > > > Sorry for the continuing questions -- I got lots of conflicting feedback > > on the last series and want to make sure v4 is more acceptable. > > In the long term I would be very happy to see us having a real interface > for this stuff, just my opinion... Yep, I think I'll try and balance the two -- fix NVMe for now with a 4K page size as suggested by Christoph, and then work on the more complete API for the next merge. Thanks, Nish