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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 E7D60C48BDF for ; Thu, 24 Jun 2021 05:37:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3045613E1 for ; Thu, 24 Jun 2021 05:37:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230118AbhFXFkE (ORCPT ); Thu, 24 Jun 2021 01:40:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhFXFkD (ORCPT ); Thu, 24 Jun 2021 01:40:03 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 510F3C061574; Wed, 23 Jun 2021 22:37:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description; bh=LzKmFEvfSqHE5WGD0woHAtqwFUsZUDbQDhrUeoqAXLU=; b=Qq5pr0qZePwVNkKzuKAolBa4m4 YNvbKkbB2jhWRkblkrfE8gWHJ9dj3iXfI7ghr5HOS3JBHwKZKZNmUx8g+MMe8po4+RuTAguV0kZ9u RybllMI6D5qJN7Jg2w6dNXTw97aaFYM2GyU8hcwVmzLexfBZm83w1GNtyzxzYGjeiciHLkvn+IHjp YC6+frbSy85QLu/PtnPFbe72+YxpaQqlQJC6tDdQeidFS8XCJ5PIrK4F6sfAV9AgO/uVvuTNRbApe EIgzUwjIwcPfqlLm0uB5g/AZw0/fKUOZx01kJHMYM2JNTQ+6k/XFmdypReBWthUXOodf5miEMYr+m FheM2fdQ==; Received: from [2601:1c0:6280:3f0::aefb] by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1lwI3a-00Cr18-0A; Thu, 24 Jun 2021 05:37:42 +0000 Subject: Re: [PATCH] Documentation, dt, numa: Add note to empty NUMA node To: Gavin Shan , devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, robh+dt@kernel.org, drjones@redhat.com, shan.gavin@gmail.com References: <20210624033740.20862-1-gshan@redhat.com> <435d4707-3871-26fe-e0e4-df93931ba49d@redhat.com> From: Randy Dunlap Message-ID: Date: Wed, 23 Jun 2021 22:37:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <435d4707-3871-26fe-e0e4-df93931ba49d@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 6/23/21 9:58 PM, Gavin Shan wrote: > On 6/24/21 12:14 PM, Randy Dunlap wrote: >> On 6/23/21 8:37 PM, Gavin Shan wrote: >>> The empty NUMA nodes, where no memory resides in, are allowed. For >>> these empty NUMA nodes, the 'len' of 'reg' property is zero. These >>> empty NUMA node IDs are still valid and parsed. I finds difficulty >>> to get where it's properly documented. >>> >>> So lets add note to empty NUMA nodes in the NUMA binding doc. >>> >>> Signed-off-by: Gavin Shan >>> --- >>>   Documentation/devicetree/bindings/numa.txt | 4 ++++ >>>   1 file changed, 4 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/numa.txt b/Documentation/devicetree/bindings/numa.txt >>> index 21b35053ca5a..c564705c0eac 100644 >>> --- a/Documentation/devicetree/bindings/numa.txt >>> +++ b/Documentation/devicetree/bindings/numa.txt >>> @@ -109,6 +109,10 @@ Example: >>>   Dual socket system consists of 2 boards connected through ccn bus and >>>   each board having one socket/soc of 8 cpus, memory and pci bus. >>>   +Note that the empty NUMA nodes, which no memory resides in, are allowed >> >> Missing period at end of the sentence above. >> > > Oh, Yes. Thanks, Randy. I will replace "resides in" with "resides in period" > in v2. Cute. Would it help if I replaced "period" with Missing "full stop" or '.' at the end of the sentence? >>> +Their NUMA node IDs are still valid so that memory can be added into these >>> +NUMA nodes through hotplug afterwards. >>> + >>>       memory@c00000 { >>>           device_type = "memory"; >>>           reg = <0x0 0xc00000 0x0 0x80000000>; > > By the way, I have one more question to check with you if I can. I'm not sure > if dummy and invalid 'unit-address' is allowed in the empty memory node name, > which follows the format "memory@unit-address'. > > (1) The 'unit-address' is same thing as to 'base address' for memory node, >     as specified in device-tree specification. I'm not sure if 'base address' >     can be dummy and invalid one since empty memory node doesn't have memory >     at all. > >     https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#node-names > > (2) I don't find the 'unit-address' is used in linux, but I'm not sure other >     software component like firmware uses it or not. I have no idea about that.