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=-16.1 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,SPF_HELO_NONE,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 38701C49EA7 for ; Fri, 25 Jun 2021 05:23:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D00361421 for ; Fri, 25 Jun 2021 05:23:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233030AbhFYF0N (ORCPT ); Fri, 25 Jun 2021 01:26:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44750 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230172AbhFYF0M (ORCPT ); Fri, 25 Jun 2021 01:26:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624598631; h=from:from: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; bh=JEzA3/KcHqjV1NTgdCCaV4I2K2xF2kBaxzJKUrI7KNU=; b=YY9H2maviywsYbXtPGTiTgJyfmyTWscx08YR2RGDkKt89EaQBOLIisW49GKtPcfvjORH6Q Qx83G8FXaOBA8iULU1oyNsXiOHz72kgPaxieZGgUFwhv8r49R7K0tE0K824QqS4+ry3HmL r4Un2Ukha+GETEaMOPk9emGB0HfQRA4= 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-487-gp0CA3GcNw-ynVpkfZy3kA-1; Fri, 25 Jun 2021 01:23:49 -0400 X-MC-Unique: gp0CA3GcNw-ynVpkfZy3kA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 79FC3802C89; Fri, 25 Jun 2021 05:23:48 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-233.bne.redhat.com [10.64.54.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3503760C05; Fri, 25 Jun 2021 05:23:45 +0000 (UTC) From: Gavin Shan To: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, rdunlap@infradead.org, robh+dt@kernel.org, drjones@redhat.com, shan.gavin@gmail.com Subject: [PATCH v4] Documentation, dt, numa: Add note to empty NUMA node Date: Fri, 25 Jun 2021 13:23:38 +0800 Message-Id: <20210625052338.4875-1-gshan@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The empty memory nodes, where no memory resides in, are allowed. For these empty memory nodes, the 'len' of 'reg' property is zero. The NUMA node IDs are still valid and parsed, but memory can be added to them through hotplug afterwards. I finds difficulty to get where it's properly documented. So lets add note to empty memory 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..0fc882e44270 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 empty memory nodes, which no memory resides in, are allowed. +The NUMA node IDs in these empty memory nodes are still valid, but +memory can be added into them through hotplug afterwards. + memory@c00000 { device_type = "memory"; reg = <0x0 0xc00000 0x0 0x80000000>; -- 2.23.0