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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 2989BC2D0E0 for ; Tue, 15 Sep 2020 10:31:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFBA82076C for ; Tue, 15 Sep 2020 10:31:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726281AbgIOKbv (ORCPT ); Tue, 15 Sep 2020 06:31:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:56026 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726153AbgIOKbu (ORCPT ); Tue, 15 Sep 2020 06:31:50 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 02318B0F2; Tue, 15 Sep 2020 10:32:04 +0000 (UTC) Date: Tue, 15 Sep 2020 12:31:45 +0200 From: Oscar Salvador To: Laurent Dufour Cc: akpm@linux-foundation.org, David Hildenbrand , mhocko@suse.com, Greg Kroah-Hartman , linux-mm@kvack.org, "Rafael J . Wysocki" , nathanl@linux.ibm.com, cheloha@linux.ibm.com, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3 2/3] mm: don't rely on system state to detect hot-plug operations Message-ID: <20200915103145.GB30015@linux> References: <20200915094143.79181-1-ldufour@linux.ibm.com> <20200915094143.79181-3-ldufour@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200915094143.79181-3-ldufour@linux.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2020 at 11:41:42AM +0200, Laurent Dufour wrote: > [1] According to Oscar Salvador, using this qemu command line, ACPI memory > hotplug operations are raised at SYSTEM_SCHEDULING state: I would like to stress that this is not the only way we can end up hotplugging memor while state = SYSTEM_SCHEDULING. According to David, we can end up doing this if we reboot a VM with hotplugged memory. (And I have seen other virtualization technologies do the same) > Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") > Signed-off-by: Laurent Dufour > Reviewed-by: David Hildenbrand > Cc: stable@vger.kernel.org > Cc: Greg Kroah-Hartman > Cc: "Rafael J. Wysocki" > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Oscar Salvador Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3