From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by kanga.kvack.org (Postfix) with ESMTP id 5709E8E0002 for ; Wed, 16 Jan 2019 16:44:38 -0500 (EST) Received: by mail-wm1-f71.google.com with SMTP id f6so1926591wmj.5 for ; Wed, 16 Jan 2019 13:44:38 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id r4sor21202567wmr.10.2019.01.16.13.44.36 for (Google Transport Security); Wed, 16 Jan 2019 13:44:37 -0800 (PST) MIME-Version: 1.0 References: <20190116181859.D1504459@viggo.jf.intel.com> <20190116181905.12E102B4@viggo.jf.intel.com> <98ab9bc8-8a17-297c-da7c-2e6b5a03ef24@intel.com> In-Reply-To: <98ab9bc8-8a17-297c-da7c-2e6b5a03ef24@intel.com> From: Bjorn Helgaas Date: Wed, 16 Jan 2019 15:44:24 -0600 Message-ID: Subject: Re: [PATCH 4/4] dax: "Hotplug" persistent memory for use like normal RAM Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Dave Hansen , Dave Hansen , Dan Williams , Dave Jiang , zwisler@kernel.org, vishal.l.verma@intel.com, thomas.lendacky@amd.com, Andrew Morton , mhocko@suse.com, linux-nvdimm@lists.01.org, Linux Kernel Mailing List , linux-mm@kvack.org, Huang Ying , Wu Fengguang , Borislav Petkov , baiyaowei@cmss.chinamobile.com, Takashi Iwai On Wed, Jan 16, 2019 at 3:40 PM Dave Hansen wrote: > On 1/16/19 1:16 PM, Bjorn Helgaas wrote: > > On Wed, Jan 16, 2019 at 12:25 PM Dave Hansen > > wrote: > >> From: Dave Hansen > >> Currently, a persistent memory region is "owned" by a device driver, > >> either the "Direct DAX" or "Filesystem DAX" drivers. These drivers > >> allow applications to explicitly use persistent memory, generally > >> by being modified to use special, new libraries. > > > > Is there any documentation about exactly what persistent memory is? > > In Documentation/, I see references to pstore and pmem, which sound > > sort of similar, but maybe not quite the same? > > One instance of persistent memory is nonvolatile DIMMS. They're > described in great detail here: Documentation/nvdimm/nvdimm.txt Thanks! Some bread crumbs in the changelog to lead there would be great. Bjorn 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=-8.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,USER_IN_DEF_DKIM_WL 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 8DE37C43387 for ; Wed, 16 Jan 2019 21:44:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 492D720652 for ; Wed, 16 Jan 2019 21:44:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WvrRJZck" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 492D720652 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CAE5C8E0003; Wed, 16 Jan 2019 16:44:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C5CCA8E0002; Wed, 16 Jan 2019 16:44:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B25F88E0003; Wed, 16 Jan 2019 16:44:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by kanga.kvack.org (Postfix) with ESMTP id 5709E8E0002 for ; Wed, 16 Jan 2019 16:44:38 -0500 (EST) Received: by mail-wm1-f71.google.com with SMTP id f6so1926591wmj.5 for ; Wed, 16 Jan 2019 13:44:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:mime-version:references :in-reply-to:from:date:message-id:subject:to:cc; bh=amyYQ0mfOwL3n6qC0TXaw+DPRTwqAe3I4F6HyJ5F61I=; b=YBbX3+FwPp231Iu0XqUL0MAc+lSdkdO2rE1XyRdnCNiHMLwBIewIdRRtAVX41lQyCp ku6aQ/soWODoynHC6ktbk86OQfRRQ9IcBgI4rnRQb+d+pmO108l4Go6ctxT9lD/cIcXR qpWQDbbNlixeIHcaq9KgjObuoM9EfwapP2ZiR4EWETF5f30EWr93WM5pT36mNdygU9nd pzmTPbHnkm6GD47G8rHiYNCl895G0fBKpV08Tl5zZcvAanjMyNS+nq1/D7cOiW786Lop e3eXOb5U2x3hufZoG/FSb5w/F/Hf5pclvYDbjhYg6T3PCLw9yJRg+0LiFudxz7BKV1tK 50NQ== X-Gm-Message-State: AJcUuke0Vgomf5soI0m/1k7StgYwGgvexLxkQ5U8Xp8zqy02rDCKsanS BfSaddcgRf/KXFhbqwWqukjT2c50dIazvZpl1j4R2r+3ND0RIaN+IZJnzq5R+4P3Xy7PILvBwB2 7lxM1Ljx+zlAf1ktLPMGEAvPbthdbc7shtEfikskG777NgGgC9jrQwQHUCWj0QQeCTf4hItJ92x Bdzr028NIvEAuEG5yYMCCmh9ocZFLRpUu+6Sj3emHeACxNpVhfJr6vR5XMiAS1YfRVJH4lXWfxB f67qjQvwcobVke5hiHhHxePCJTRnnoDa7mdPbw79SpK6SrHAEgoKhh92CLr6BQLFLGbrUPSm70o 0FdweaJs7wRpLWnBocNgKgYpbu3D7fyqi7qPQ5FynDQ2BJHv2DndoSvmJGvwZlTfaeta4KtwVW4 W X-Received: by 2002:a1c:2902:: with SMTP id p2mr9037415wmp.19.1547675077917; Wed, 16 Jan 2019 13:44:37 -0800 (PST) X-Received: by 2002:a1c:2902:: with SMTP id p2mr9037385wmp.19.1547675077045; Wed, 16 Jan 2019 13:44:37 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1547675077; cv=none; d=google.com; s=arc-20160816; b=ba1AQxvoVReW7/CHzb69M0PTDFFtkyPSnk0zdiO2HyNZ77YwrqSv8gawj2xiKj5Ud4 Wb1F7c8+t2vOrm4rYEwkft9m6JDxq4LbizeOddm5/H2MkpL+YFl/YBcK6WGzB1fBwVqo 3jYz/KbFL01CUqoEUwUG2UdjR3Sh7mMzUQcqef0eE4xjOEzvErA5C7/YcU/nxMIupI8d vDV6CnmGTjBJyMfFit3LV+NAMsFPIvH6/Z6mbDpz289azufxi9Lua4CLcgSUBfa7do0l oNBlhAm8rtKOpt1AjVcuUWxCLrkw9r9bv9eRh/85p6S7s3+Md00j8JuNaoBZ2Y8uHz0k 9diA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=amyYQ0mfOwL3n6qC0TXaw+DPRTwqAe3I4F6HyJ5F61I=; b=0ZcKOrxPwOrkYFX7cRCjGn5g0G7F1lYdprnQAZy97S+ThW45cdVMvw+W5ZOKbAv1zX xkJ/hoWROFChyj6gw1yInLrDfMqyaG0KKv95pdy+iBAPycj5fyr5iWWDeAQAl1ZhTvkN eMtHMktm90kr4v6ri5OuUVsuMovcB+aSrEr/a27fYkd7iG3E03TcrrH1fcSFSMfS2cS+ 8AZeT0sb8MsyQGa7E84PDRchlAWLisQwx9imJbJwiVxKG8iel4DzIGO/Yi2qGKhuINph WlSWqq7Tso27wOGWZEWAAP8vVvZSGbo2Xh38+oW7RdSwy15xAfJuoSLuxngfpq0Km4ZT 6p5A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=WvrRJZck; spf=pass (google.com: domain of bhelgaas@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=bhelgaas@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id r4sor21202567wmr.10.2019.01.16.13.44.36 for (Google Transport Security); Wed, 16 Jan 2019 13:44:37 -0800 (PST) Received-SPF: pass (google.com: domain of bhelgaas@google.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=WvrRJZck; spf=pass (google.com: domain of bhelgaas@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=bhelgaas@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=amyYQ0mfOwL3n6qC0TXaw+DPRTwqAe3I4F6HyJ5F61I=; b=WvrRJZckgwYnrL8o7H1BhdjbnhUOYZ5cIpiQdXpURKsYQUjBW2kOU4fugchO1Cl4cG I/S6SqE+nOQTxvbLPDMfKOPzbnDzFkZhooeD8XGQ0EnzNKKCEgkkxvJALkT0CMe6Kywr ZwpQ7x9EkJMHlUql89jGO5p0M7ATjqCAxzwGzychKyRuj536GlWdmov6D4A5G48RGA97 yEP1BQ9JK95B5AA8idfBRF6opo+UmIX1Yk1OQs2uZg0aUdP7Anmr3dK8UbeQ4ymZS/yC qAIv2cbK03txqy/MH7MrDZL0H6nUWVgBTCVY28kOU8wgJ15IeorgnSEIIvrhQrC3iIS/ Szxw== X-Google-Smtp-Source: ALg8bN4aRs8NjUoaYnVv6BJ5a7G4g1K/+JOsgkZQhu8PJhsiMXYYgLxhSUX8+eErltERHwUCx6l/99SRc8QVR567Q/A= X-Received: by 2002:a1c:5984:: with SMTP id n126mr8815661wmb.62.1547675076484; Wed, 16 Jan 2019 13:44:36 -0800 (PST) MIME-Version: 1.0 References: <20190116181859.D1504459@viggo.jf.intel.com> <20190116181905.12E102B4@viggo.jf.intel.com> <98ab9bc8-8a17-297c-da7c-2e6b5a03ef24@intel.com> In-Reply-To: <98ab9bc8-8a17-297c-da7c-2e6b5a03ef24@intel.com> From: Bjorn Helgaas Date: Wed, 16 Jan 2019 15:44:24 -0600 Message-ID: Subject: Re: [PATCH 4/4] dax: "Hotplug" persistent memory for use like normal RAM To: Dave Hansen Cc: Dave Hansen , Dave Hansen , Dan Williams , Dave Jiang , zwisler@kernel.org, vishal.l.verma@intel.com, thomas.lendacky@amd.com, Andrew Morton , mhocko@suse.com, linux-nvdimm@lists.01.org, Linux Kernel Mailing List , linux-mm@kvack.org, Huang Ying , Wu Fengguang , Borislav Petkov , baiyaowei@cmss.chinamobile.com, Takashi Iwai Content-Type: text/plain; charset="UTF-8" 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: <20190116214424.bKyo-l8XBWwilauWDQ_I0FcWv0Zw7QfxjtjlU1y5RF4@z> On Wed, Jan 16, 2019 at 3:40 PM Dave Hansen wrote: > On 1/16/19 1:16 PM, Bjorn Helgaas wrote: > > On Wed, Jan 16, 2019 at 12:25 PM Dave Hansen > > wrote: > >> From: Dave Hansen > >> Currently, a persistent memory region is "owned" by a device driver, > >> either the "Direct DAX" or "Filesystem DAX" drivers. These drivers > >> allow applications to explicitly use persistent memory, generally > >> by being modified to use special, new libraries. > > > > Is there any documentation about exactly what persistent memory is? > > In Documentation/, I see references to pstore and pmem, which sound > > sort of similar, but maybe not quite the same? > > One instance of persistent memory is nonvolatile DIMMS. They're > described in great detail here: Documentation/nvdimm/nvdimm.txt Thanks! Some bread crumbs in the changelog to lead there would be great. Bjorn