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=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 EE101C48BC2 for ; Thu, 24 Jun 2021 02:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6E4F61209 for ; Thu, 24 Jun 2021 02:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229800AbhFXC67 (ORCPT ); Wed, 23 Jun 2021 22:58:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46753 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229907AbhFXC64 (ORCPT ); Wed, 23 Jun 2021 22:58:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624503398; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2eSA6/HlHvadNSOU/l/uauEc2fo4rHElHGAVhTWFqfg=; b=hI2qLnSlyUevs6SkqqHWuTINXyzAltnkrpBf2WKe16k4c587VgT3Rxhyf69w7ld+4V9djv zNklHF7CqjeK52cLQSMr6fursPtovyev51sN9sjcc0LQEigMNLHt236MIo6GgWL4Xh/gXX 8tdOs1EU/HuQ5ugZzCpMApVel6jL9c0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-475-pBXycZq0PzWfpTXSRvXuVQ-1; Wed, 23 Jun 2021 22:56:36 -0400 X-MC-Unique: pBXycZq0PzWfpTXSRvXuVQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 49F86802C88; Thu, 24 Jun 2021 02:56:35 +0000 (UTC) Received: from [10.64.54.70] (vpn2-54-70.bne.redhat.com [10.64.54.70]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 64B0A1001281; Thu, 24 Jun 2021 02:56:33 +0000 (UTC) Reply-To: Gavin Shan Subject: Re: [PATCH] Documentation, dt, numa: Add note to empty NUMA node To: Randy Dunlap , 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> From: Gavin Shan Message-ID: <435d4707-3871-26fe-e0e4-df93931ba49d@redhat.com> Date: Thu, 24 Jun 2021 14:58:02 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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. >> +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. Thanks, Gavin