From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752240AbbCZQHi (ORCPT ); Thu, 26 Mar 2015 12:07:38 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:37012 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752123AbbCZQHe (ORCPT ); Thu, 26 Mar 2015 12:07:34 -0400 Message-ID: <55142EC2.8060507@plexistor.com> Date: Thu, 26 Mar 2015 18:07:30 +0200 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Dan Williams CC: Christoph Hellwig , Ingo Molnar , Jens Axboe , linux-nvdimm , X86 ML , "linux-kernel@vger.kernel.org" , linux-fsdevel Subject: Re: [Linux-nvdimm] [PATCH 2/3] x86: add a is_e820_ram() helper References: <1427358764-6126-1-git-send-email-hch@lst.de> <1427358764-6126-3-git-send-email-hch@lst.de> <20150326090215.GA11520@gmail.com> <20150326093424.GA28217@lst.de> <55142A92.4060607@plexistor.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/26/2015 06:02 PM, Dan Williams wrote: > On Thu, Mar 26, 2015 at 8:49 AM, Boaz Harrosh wrote: >> On 03/26/2015 11:34 AM, Christoph Hellwig wrote: >>> +/* >>> + * This is a non-standardized way to represent ADR or NVDIMM regions that >>> + * persist over a reboot. The kernel will ignore their special capabilities >>> + * unless the CONFIG_X86_PMEM_LEGACY option is set. >>> + * >>> + * Note that older platforms also used 6 for the same type of memory, >>> + * but newer versions switched to 12 as 6 was assigned differently. Some >>> + * time they will learn.. >>> + */ >>> +#define E820_PRAM 12 >> >> Why the PRAM Name. For one 2/3 of this patch say PMEM the Kconfig >> to enable is _PMEM_, the driver stack that gets loaded is pmem, >> so PRAM is unexpected. >> >> Also I do believe PRAM is not the correct name. Yes NvDIMMs are RAM, >> but there are other not RAM technologies that can be supported exactly >> the same way. >> MEM is a more general name meaning "on the memory bus". I think. >> >> I would love the consistency. > > One of nice side of effects of having a "PRAM" name is that we can > later add a UEFI "PMEM" type where the distinction is thsy "PRAM" is > included in the system memory map by default and "PMEM" is analogous > to "IOMEM". Just a thought... > Than lets say E820_PMEM_12, but not PRAM for sure. Also would UEFI be E820_XXX will it not be a UEFI_PMEM ?? For me I hate RAM because it became to mean a technology, maybe then the same name as the Kconfig PMEM_LEGACY Thanks Boaz