From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by kanga.kvack.org (Postfix) with ESMTP id 024688E0002 for ; Thu, 17 Jan 2019 11:29:15 -0500 (EST) Received: by mail-qt1-f200.google.com with SMTP id d31so9610513qtc.4 for ; Thu, 17 Jan 2019 08:29:14 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id u4si315473qkc.197.2019.01.17.08.29.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 17 Jan 2019 08:29:14 -0800 (PST) From: Jeff Moyer Subject: Re: [PATCH 0/4] Allow persistent memory to be used like normal RAM References: <20190116181859.D1504459@viggo.jf.intel.com> Date: Thu, 17 Jan 2019 11:29:10 -0500 In-Reply-To: <20190116181859.D1504459@viggo.jf.intel.com> (Dave Hansen's message of "Wed, 16 Jan 2019 10:18:59 -0800") Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: dave@sr71.net, thomas.lendacky@amd.com, mhocko@suse.com, linux-nvdimm@lists.01.org, tiwai@suse.de, ying.huang@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bp@suse.de, baiyaowei@cmss.chinamobile.com, zwisler@kernel.org, bhelgaas@google.com, fengguang.wu@intel.com, akpm@linux-foundation.org Dave Hansen writes: > Persistent memory is cool. But, currently, you have to rewrite > your applications to use it. Wouldn't it be cool if you could > just have it show up in your system like normal RAM and get to > it like a slow blob of memory? Well... have I got the patch > series for you! So, isn't that what memory mode is for? https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/ Why do we need this code in the kernel? -Jeff 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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 EA48FC43612 for ; Thu, 17 Jan 2019 16:29:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ADD5820855 for ; Thu, 17 Jan 2019 16:29:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADD5820855 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4A9CB8E000B; Thu, 17 Jan 2019 11:29:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 42F9A8E0002; Thu, 17 Jan 2019 11:29:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2F7FB8E000B; Thu, 17 Jan 2019 11:29:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by kanga.kvack.org (Postfix) with ESMTP id 024688E0002 for ; Thu, 17 Jan 2019 11:29:15 -0500 (EST) Received: by mail-qt1-f200.google.com with SMTP id d31so9610513qtc.4 for ; Thu, 17 Jan 2019 08:29:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:references:date:in-reply-to:message-id:user-agent :mime-version; bh=sF4B3kTinlBQONTKYJIx0PSeVWK4itW9iPsPCWk5Cg4=; b=qB1IyhOUOthX0LCDRAeJYN8/rSZkK0hF/o36U6bMSKLgoQvuEN15ClHy2pcRUbDysX poTwVBi3Y4ankLx66h/MXjFQNpJdeganitoq73ehp2uNQyjjn94Jp7d8Y89K/gII7Rm8 651WRT+USwoA4P3gDk4acaFlP7PHhyPissOLMdJ5RkI0sl0T9o1KKjc8UbNlwv112M5f 6yANIxO8BlL6EDCpUTP/1A4RhXTNLUYmY1TwUqa7rVXO75tCqJG4mNk0MPGop2ryqDLu lieYCAwxdoG4V+HB9JEVzMYDS15sxJ2qTmh0HaifYigHbTRhgqRJvn5dhNlIxEWV4/rQ zP1Q== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of jmoyer@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jmoyer@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Gm-Message-State: AJcUukcq55Jljv9oe75gCE/a3y5xT+YUWKRSQQdBsITilFqevpejksym AAi+vrtcZ0DizRHS+PDyl4EsACkeHVy+Pc/lLEDvbtLHxBiA0g19jDqXqfgYb/heByPEX4/tNaR BLcnYMG4sZ9fV+QzU349YA6lCxXCHETOlHmNuyW3YMd25/xVvG+Nx8Y473WJv/MR9zw== X-Received: by 2002:a37:4e58:: with SMTP id c85mr11671195qkb.27.1547742554735; Thu, 17 Jan 2019 08:29:14 -0800 (PST) X-Google-Smtp-Source: ALg8bN6zq/EcOQAvZ9lQZVHHgXqqj1p2gxACeYZMzWAI0G50nWYZeUtbeiRzQDNrQ6qx3WwwcqeY X-Received: by 2002:a37:4e58:: with SMTP id c85mr11671154qkb.27.1547742554238; Thu, 17 Jan 2019 08:29:14 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1547742554; cv=none; d=google.com; s=arc-20160816; b=thN4hDmhoVRpVuvtI98P+hTWhprOujTRigKs40x5TUhepJWhpu/czt1KbS520m1Otc WiaaNPZ6z/CV4dgQV8CMWKjTQhagonqGA9ilVNNY+tFTb1wz+72MaGZNo8/RrFbhsAh8 y7mwu3W4cVFBv7euFjTrGN+ctIzcRhUkRn/IWCcwvxg1AAa2hg9fPwPfAUMYEn/qAHzd X6NIWhr5PC3L+11Etwx8VChWVN4+dHdeBH3BA8KI5X430xjVdIXS2Vix1O2JjMnW2yg5 xvYFpVD+2sAQ+GR4WIn9oIjKGAAvKWhBwcEZNDDBOJmX+aIG77DO6Ges2dwUTUWJe8oc dNMw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from; bh=sF4B3kTinlBQONTKYJIx0PSeVWK4itW9iPsPCWk5Cg4=; b=ePN/VOu2BYnUTmCvpO8RmbkDiEfrr4E2p8Lku2nNbfTBgedtI3A7b6WmJFnpucdHBC jPR3i9tDNO9GU79bkgaCuxYse7KarBbFQPRsL5tauq1x2z/j8lcY98w4S5Vj0fL5hBYJ cILLSj4/ZJZjm8dXUT9n7rYaVMait22uKtu16loWOYl59MkbiSOcAlv3Hlwrq+B9AFCA 7IHkGO3tYv72e/wnk/0HHshGfKPeGMq+yM7vIaGcdm1b3IToaQXqikTbDp+1o3lqifcA XB71jI2dkIf82y/6sDFXM7gzOuPL7qhsu7p4Mn7pVSLIFKOJa2GNo7jhnm2im6Ha58Qi SJ5A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of jmoyer@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jmoyer@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id u4si315473qkc.197.2019.01.17.08.29.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 17 Jan 2019 08:29:14 -0800 (PST) Received-SPF: pass (google.com: domain of jmoyer@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jmoyer@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jmoyer@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 22911804F8; Thu, 17 Jan 2019 16:29:13 +0000 (UTC) Received: from segfault.boston.devel.redhat.com (segfault.boston.devel.redhat.com [10.19.60.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9CD1C60933; Thu, 17 Jan 2019 16:29:11 +0000 (UTC) From: Jeff Moyer To: Dave Hansen Cc: dave@sr71.net, thomas.lendacky@amd.com, mhocko@suse.com, linux-nvdimm@lists.01.org, tiwai@suse.de, ying.huang@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bp@suse.de, baiyaowei@cmss.chinamobile.com, zwisler@kernel.org, bhelgaas@google.com, fengguang.wu@intel.com, akpm@linux-foundation.org Subject: Re: [PATCH 0/4] Allow persistent memory to be used like normal RAM References: <20190116181859.D1504459@viggo.jf.intel.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 Date: Thu, 17 Jan 2019 11:29:10 -0500 In-Reply-To: <20190116181859.D1504459@viggo.jf.intel.com> (Dave Hansen's message of "Wed, 16 Jan 2019 10:18:59 -0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 17 Jan 2019 16:29:13 +0000 (UTC) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Message-ID: <20190117162910.s8_4djPiooye4V9HrZIrWQF6fVdnnyHohgmqiSV_K-8@z> Dave Hansen writes: > Persistent memory is cool. But, currently, you have to rewrite > your applications to use it. Wouldn't it be cool if you could > just have it show up in your system like normal RAM and get to > it like a slow blob of memory? Well... have I got the patch > series for you! So, isn't that what memory mode is for? https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/ Why do we need this code in the kernel? -Jeff