Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753909AbbFVTLQ (ORCPT ); Mon, 22 Jun 2015 15:11:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50249 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522AbbFVTLH (ORCPT ); Mon, 22 Jun 2015 15:11:07 -0400 From: Jeff Moyer To: Dan Williams Cc: Christoph Hellwig , Jens Axboe , "linux-nvdimm\@lists.01.org" , "linux-kernel\@vger.kernel.org" , Linux ACPI , linux-fsdevel , Ingo Molnar Subject: Re: [PATCH 14/15] libnvdimm: support read-only btt backing devices References: <20150622063028.GA30434@lst.de> <20150622072844.GA31263@lst.de> <20150622154138.GC7952@lst.de> <20150622163224.GA9168@lst.de> <20150622164804.GA9393@lst.de> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 22 Jun 2015 15:11:05 -0400 In-Reply-To: (Dan Williams's message of "Mon, 22 Jun 2015 12:04:05 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) 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 Content-Length: 807 Lines: 21 Dan Williams writes: >>> Direct I/O using application can make assumption if they know the sector >>> size, and we must have a way for them to be able to see our new >>> "subsector sector size". >> >> You need to let them determine that when NOT using the btt, yes. Right >> now, I don't think there's a way to determine what the underlying atomic >> write unit is. That's something the NFIT spec probably should have >> defined. > > There are no atomic write units for NFIT to advertise beyond cpu register width. That would be useful information for the platform to provide, instead of requiring the o/s or applications to infer it. Cheers, Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/