From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by kanga.kvack.org (Postfix) with ESMTP id 773A38E0002 for ; Wed, 16 Jan 2019 16:59:42 -0500 (EST) Received: by mail-wr1-f72.google.com with SMTP id l1so3720332wrn.3 for ; Wed, 16 Jan 2019 13:59:42 -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 69sor23830735wmy.3.2019.01.16.13.59.41 for (Google Transport Security); Wed, 16 Jan 2019 13:59:41 -0800 (PST) MIME-Version: 1.0 References: <20190116181859.D1504459@viggo.jf.intel.com> <20190116181905.12E102B4@viggo.jf.intel.com> In-Reply-To: From: Bjorn Helgaas Date: Wed, 16 Jan 2019 15:59:28 -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 3:53 PM Dave Hansen wrote: > > On 1/16/19 1:16 PM, Bjorn Helgaas wrote: > >> + /* > >> + * Set flags appropriate for System RAM. Leave ..._BUSY clear > >> + * so that add_memory() can add a child resource. > >> + */ > >> + new_res->flags = IORESOURCE_SYSTEM_RAM; > > IIUC, new_res->flags was set to "IORESOURCE_MEM | ..." in the > > devm_request_mem_region() path. I think you should keep at least > > IORESOURCE_MEM so the iomem_resource tree stays consistent. > > I went to look at fixing this. It looks like "IORESOURCE_SYSTEM_RAM" > includes IORESOURCE_MEM: > > > #define IORESOURCE_SYSTEM_RAM (IORESOURCE_MEM|IORESOURCE_SYSRAM) > > Did you want the patch to expand this #define, or did you just want to > ensure that IORESORUCE_MEM got in there somehow? The latter. Since it's already included, forget I said anything :) Although if your intent is only to clear IORESOURCE_BUSY, maybe it would be safer to just clear that bit instead of overwriting everything? That might also help people grepping for IORESOURCE_BUSY usage. 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[209.85.220.65]) by mx.google.com with SMTPS id 69sor23830735wmy.3.2019.01.16.13.59.41 for (Google Transport Security); Wed, 16 Jan 2019 13:59:41 -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="f/BWr3r+"; 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=6qIfL8Zi2BtD5K9xGzCCu2hOnxmvhp5ChjrJu31awZE=; b=f/BWr3r+8ex/j4S381sHZg6EeV8ry9z0Atj7CQIjjMV7CZ+VkFOL626b6L+T9/e8qH AV55WLrud4Z4wCUYOTIx70Ml2zS1spEnZ4VVP8XBn8jY5XvSwp3OoEPj+K7Bi4auqhxf PYbpsbR6Uhwn3TT3iH7OOzj+6mUTRGkdMWYxbpAmgVfWkXJDvOmFcAGfvI34+w5d7ieB QpIkx+ZHiFXH1BUhTDbv1uBfRRLvHsd2DrcWWtc1EU6tw/zlRRSrsnT0jfByq5fhujJV XI37In3FiNudTdvS0CgWnxzHiqTZXSzGllKziYiEvehtdcadEXf+dT9BsYM0VtfUwTFt YsBg== X-Google-Smtp-Source: ALg8bN7DFQ+VFScKFhjl+kHX02LbzQtshD6fLYiI7hu9xwk9q+DRsE0s/fr3ogHGivCalOmsl3MbopOjws5wT8biNJA= X-Received: by 2002:a1c:5984:: with SMTP id n126mr8847488wmb.62.1547675980793; Wed, 16 Jan 2019 13:59:40 -0800 (PST) MIME-Version: 1.0 References: <20190116181859.D1504459@viggo.jf.intel.com> <20190116181905.12E102B4@viggo.jf.intel.com> In-Reply-To: From: Bjorn Helgaas Date: Wed, 16 Jan 2019 15:59:28 -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: <20190116215928.Q1NfIyme6aTxR0yzTvla0_Q9W45HrFho3eDwYOm4Nq8@z> On Wed, Jan 16, 2019 at 3:53 PM Dave Hansen wrote: > > On 1/16/19 1:16 PM, Bjorn Helgaas wrote: > >> + /* > >> + * Set flags appropriate for System RAM. Leave ..._BUSY clear > >> + * so that add_memory() can add a child resource. > >> + */ > >> + new_res->flags = IORESOURCE_SYSTEM_RAM; > > IIUC, new_res->flags was set to "IORESOURCE_MEM | ..." in the > > devm_request_mem_region() path. I think you should keep at least > > IORESOURCE_MEM so the iomem_resource tree stays consistent. > > I went to look at fixing this. It looks like "IORESOURCE_SYSTEM_RAM" > includes IORESOURCE_MEM: > > > #define IORESOURCE_SYSTEM_RAM (IORESOURCE_MEM|IORESOURCE_SYSRAM) > > Did you want the patch to expand this #define, or did you just want to > ensure that IORESORUCE_MEM got in there somehow? The latter. Since it's already included, forget I said anything :) Although if your intent is only to clear IORESOURCE_BUSY, maybe it would be safer to just clear that bit instead of overwriting everything? That might also help people grepping for IORESOURCE_BUSY usage.