From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757095AbbJ3BdO (ORCPT ); Thu, 29 Oct 2015 21:33:14 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:59338 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751917AbbJ3BdM (ORCPT ); Thu, 29 Oct 2015 21:33:12 -0400 Date: Thu, 29 Oct 2015 18:49:55 -0700 (PDT) Message-Id: <20151029.184955.728736673434401711.davem@davemloft.net> To: nacc@linux.vnet.ibm.com 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 From: David Miller In-Reply-To: <20151029155701.GJ7716@linux.vnet.ibm.com> References: <20151028135922.GA27909@localhost.localdomain> <20151029115536.GA28090@infradead.org> <20151029155701.GJ7716@linux.vnet.ibm.com> X-Mailer: Mew version 6.4 on Emacs 23.4 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 29 Oct 2015 18:33:12 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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...