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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 E28ADC43215 for ; Wed, 27 Nov 2019 22:15:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE62D215F2 for ; Wed, 27 Nov 2019 22:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574892936; bh=tzkKiC5bw0wXwgBywju5t0wQAzDG3AO9cKzzRulLeJ0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=JHMW98grlD2FWXE6Giui0FejhNRSGBmv4ZjgrYwe1pjE1iVUuDfnfYfiv6DhlmVy4 UnzOcETlvWQL6dwidFEWnbrVbzsWOR8K+Vf5TP/i4F8VUmzbsW5asCz3cJ5fbv35y0 3uVfchj8JbhAb3MNkPSMrA1dOPTgiBmuT61VJ5xA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727337AbfK0WPf (ORCPT ); Wed, 27 Nov 2019 17:15:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:39088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727051AbfK0WPf (ORCPT ); Wed, 27 Nov 2019 17:15:35 -0500 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 602FF206F0; Wed, 27 Nov 2019 22:15:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574892933; bh=tzkKiC5bw0wXwgBywju5t0wQAzDG3AO9cKzzRulLeJ0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BBiSldletvBXjGw0DWsofLb8V9rzhy9b/rEvoUWEBEUeujA12g4vGti4+gs4xcubU kVjiPKf4X7ojfrD3ssXbKUVBJ/apWq28gwF6w5zTG62sgJ/bLmSmf4zlsDjpLxCFGz F8PGxTb1w6+mPeiw0FJ5mgfAhkErEhyyWaA72yG8= Date: Wed, 27 Nov 2019 14:15:32 -0800 From: Andrew Morton To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Stephen Rothwell , Pavel Tatashin , Michal Hocko , Oscar Salvador , Chris von Recklinghausen Subject: Re: [PATCH v2] drivers/base/node.c: Simplify unregister_memory_block_under_nodes() Message-Id: <20191127141532.525708b65a96fd614595bae8@linux-foundation.org> In-Reply-To: References: <20190719135244.15242-1-david@redhat.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Nov 2019 17:53:12 +0100 David Hildenbrand wrote: > Just a note that this was actually also a bugfix as noted by Chris. > > If the memory we are removing was never onlined, > get_nid_for_pfn()->pfn_to_nid() will return garbage. Removing will > succeed but links will remain in place. > > Can be triggered by > > 1. hotplugging a DIMM to node 1 > 2. not onlining the memory blocks > 3. unplugging it > 4. re-plugging it to node 1 > > We will trigger the BUG_ON(ret) in add_memory_resource(), because > link_mem_sections() will return with -EEXIST. Oh. In that case case we please redo the patch as a bugfix? Appropriate title and changelog? And perhaps the bugfix can be split from the cleanup, to make the former more backportable?