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=-6.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 6F588C433E1 for ; Mon, 24 Aug 2020 04:10:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56A3C20768 for ; Mon, 24 Aug 2020 04:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726225AbgHXEKD (ORCPT ); Mon, 24 Aug 2020 00:10:03 -0400 Received: from foss.arm.com ([217.140.110.172]:51932 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726413AbgHXEKB (ORCPT ); Mon, 24 Aug 2020 00:10:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BB4231063; Sun, 23 Aug 2020 21:10:00 -0700 (PDT) Received: from [10.163.67.29] (unknown [10.163.67.29]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D58BE3F66B; Sun, 23 Aug 2020 21:09:57 -0700 (PDT) Subject: Re: [PATCH V2] arm64/hotplug: Improve memory offline event notifier To: linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas , Will Deacon , Mark Rutland , Marc Zyngier , Steve Capper , Mark Brown , linux-kernel@vger.kernel.org, Will Deacon References: <1598241869-28416-1-git-send-email-anshuman.khandual@arm.com> From: Anshuman Khandual Message-ID: <15c8debd-b388-ec75-742f-5401a5546db4@arm.com> Date: Mon, 24 Aug 2020 09:39:25 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1598241869-28416-1-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/24/2020 09:34 AM, Anshuman Khandual wrote: > This brings about three different changes to the sole memory event notifier > for arm64 platform and improves it's robustness while also enhancing debug > capabilities during potential memory offlining error conditions. > > This moves the memory notifier registration bit earlier in the boot process > from device_initcall() to setup_arch() which will help in guarding against > potential early boot memory offline requests. > > This enables MEM_OFFLINE memory event handling. It will help intercept any > possible error condition such as if boot memory some how still got offlined > even after an expilicit notifier failure, potentially by a future change in > generic hotplug framework. This would help detect such scenarious and help > debug further. > > It also adds a validation function which scans entire boot memory and makes > sure that early memory sections are online. This check is essential for the > memory notifier to work properly as it cannot prevent boot memory offlining > if they are not online to begin with. But this additional sanity check is > enabled only with DEBUG_VM. > > Cc: Catalin Marinas > Cc: Will Deacon Wrong email address here for Will. + Will Deacon s/will@kernel.com/will@kernel.org next time around.