From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965079AbdKCCcv (ORCPT ); Thu, 2 Nov 2017 22:32:51 -0400 Received: from ozlabs.org ([103.22.144.67]:59303 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964922AbdKCCct (ORCPT ); Thu, 2 Nov 2017 22:32:49 -0400 From: Michael Ellerman To: Dan Williams , linux-nvdimm@lists.01.org Cc: Benjamin Herrenschmidt , Heiko Carstens , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, Paul Mackerras , Martin Schwidefsky , linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, hch@lst.de, Arnd Bergmann Subject: Re: [PATCH 02/15] mm, dax: introduce pfn_t_special() In-Reply-To: <150949210553.24061.5992572975056748512.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150949209290.24061.6283157778959640151.stgit@dwillia2-desk3.amr.corp.intel.com> <150949210553.24061.5992572975056748512.stgit@dwillia2-desk3.amr.corp.intel.com> Date: Fri, 03 Nov 2017 13:32:44 +1100 Message-ID: <87ines6qib.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dan Williams writes: > In support of removing the VM_MIXEDMAP indication from DAX VMAs, > introduce pfn_t_special() for drivers to indicate that _PAGE_SPECIAL > should be used for DAX ptes. This also helps identify drivers like > dccssblk that only want to use DAX in a read-only fashion without > get_user_pages() support. > > Ideally we could delete axonram and dcssblk DAX support, but if we need > to keep it better make it explicit that axonram and dcssblk only support > a sub-set of DAX due to missing _PAGE_DEVMAP support. I sent a patch to remove axonram (sorry meant to Cc you): http://patchwork.ozlabs.org/patch/833588/ Will see if there's any feedback. cheers