Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752686AbbFVPCh (ORCPT ); Mon, 22 Jun 2015 11:02:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56031 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbbFVPC0 (ORCPT ); Mon, 22 Jun 2015 11:02:26 -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: <20150617235209.12943.24419.stgit@dwillia2-desk3.amr.corp.intel.com> <20150617235602.12943.24958.stgit@dwillia2-desk3.amr.corp.intel.com> <20150621101346.GF5915@lst.de> <20150621135406.GA9572@lst.de> <20150622063028.GA30434@lst.de> <20150622072844.GA31263@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 11:02:24 -0400 In-Reply-To: (Dan Williams's message of "Mon, 22 Jun 2015 00:39:34 -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: 772 Lines: 18 Dan Williams writes: >> Sounds like we simply shouldn't merge btt at all for now and wait for >> a real use case, which would simplify the whole issue a lot. > > The sinister aspect of sector tearing is that most applications don't > know they have this dependency. At least today's disk's rarely ever > tear sectors and if they do you almost certainly get a CRC error on > access. NVDIMMs will always tear and always silently. I think not > merging BTT at all to see what happens is simply wrong. Agreed, we can't audit all code, and springing this potential data corruptor on people seems irresponsible. -Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/