From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C75BC43387 for ; Thu, 3 Jan 2019 07:27:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06CFC2073D for ; Thu, 3 Jan 2019 07:27:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VVQq6MsK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728356AbfACH16 (ORCPT ); Thu, 3 Jan 2019 02:27:58 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:39122 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726284AbfACH15 (ORCPT ); Thu, 3 Jan 2019 02:27:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1TPZzdOpDPWLPOhH8mxvDnHt4hhXxuCtSeUDHqDjyNs=; b=VVQq6MsKqREbh+OCjpKp2k/0m TFSob1y3qINFvFlX7fOdPuuA2DiHb7+7/PWkhYBW2Qx5DHpKIX4xE6E3Q/2fX9Er++4j+H329h7BW Z5S4OZ2k4GAyLsXLiGL5/S3rg3QC/XRX5+UwMbgn/Y0HbdNMQ7CHeZM3gkpGEQNomnNc0PqCpqriH HYpDsBc0Ovg2spG2HXE6SwkJi1kEV0wfmhkH+8lvgVnkZs5m1ZydjXxe5EnncUKoH+NtJC1GP1zqV W9RhhDR2iAxgwwqn7eto7sDfC/Ss/CTNT/3Lf203qTaPIHe4iTTYhLd+MIm9K7bO6JW9omGMp9vHG AA852GB4A==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gexQ2-00023L-V4; Thu, 03 Jan 2019 07:27:54 +0000 Date: Wed, 2 Jan 2019 23:27:54 -0800 From: Christoph Hellwig To: Linus Torvalds Cc: Mikulas Patocka , Christoph Hellwig , Mike Snitzer , dm-devel@redhat.com, linux-block , Alasdair G Kergon , AliOS system security , Colin Ian King , Eric Biggers , Heinz Mauelshagen , Jaegeuk Kim , Milan Broz , Nikos Tsironis , Shenghui Wang , Sweet Tea , wuzhouhui Subject: Re: [git pull] device mapper changes for 4.21 Message-ID: <20190103072754.GA2667@infradead.org> References: <20181227160944.GA12190@redhat.com> <20181230090646.GB1022@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Sun, Dec 30, 2018 at 04:25:46PM -0800, Linus Torvalds wrote: > On Sun, Dec 30, 2018 at 11:15 AM Mikulas Patocka wrote: > > > > But you're right that 2TiB devices are common and that perhaps this option > > should go away. > > 2TiB devices are definitely not common in the one situation where this > option might matter: small embedded devices. > > I don't think the cost of 64 bit is in the arithmetic, but it might be > in some of the data structures. > > But my gut feel is that it probably doesn't much matter, and we could > get rid of the config option without anybody ever noticing. I don't > think we have that many data structures with 'sector_t' in them. > > We might try to first just force the option on, and see if anybody even cares. Our smallest embedded devices use raw flash using the MTD subsystem, and even that is using 64-bit size types everywhere. So I'd be really surprised if it is an issue. > > Linus ---end quoted text---