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=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED, 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 2F2DDC2BBCA for ; Thu, 17 Dec 2020 17:33:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 039A3235DD for ; Thu, 17 Dec 2020 17:33:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729339AbgLQRdD (ORCPT ); Thu, 17 Dec 2020 12:33:03 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56413 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727723AbgLQRdD (ORCPT ); Thu, 17 Dec 2020 12:33:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608226295; 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: in-reply-to:in-reply-to:references:references; bh=LYVIiF4Gn/aHwBT0KTOHZFeFmIOQZceUilaaNh8vrQs=; b=fb8v9oM2AphQTF9XxEXMh+wqX7/EZJlaYUDkCskQ4N1K8DEAvPCcv/Om4y2CRURQ0WMr3N xtJUGsYV7gDYPXPnxuSYuN5H1m7hf17JWxG89fQJUJo6muORug8WPqovKHx1AXPZ8Zo6xs VKNk7yUKJuqGW9fUvtBGrz577YtxoCY= 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-311-zn8ouYE1OGS1ATyDHor-6g-1; Thu, 17 Dec 2020 12:31:31 -0500 X-MC-Unique: zn8ouYE1OGS1ATyDHor-6g-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 982C11936B85; Thu, 17 Dec 2020 17:31:29 +0000 (UTC) Received: from [10.36.113.93] (ovpn-113-93.ams2.redhat.com [10.36.113.93]) by smtp.corp.redhat.com (Postfix) with ESMTP id 209BD74E87; Thu, 17 Dec 2020 17:31:25 +0000 (UTC) Subject: Re: [PATCH V2 0/3] mm/hotplug: Pre-validate the address range with platform To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland References: <1608218912-28932-1-git-send-email-anshuman.khandual@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <5eba82eb-d807-087c-41ba-b79ea8510317@redhat.com> Date: Thu, 17 Dec 2020 18:31:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <1608218912-28932-1-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.12.20 16:28, Anshuman Khandual wrote: > This series adds a mechanism allowing platforms to weigh in and prevalidate > incoming address range before proceeding further with the memory hotplug. > This helps prevent potential platform errors for the given address range, > down the hotplug call chain, which inevitably fails the hotplug itself. > > This mechanism was suggested by David Hildenbrand during another discussion > with respect to a memory hotplug fix on arm64 platform. > > https://lore.kernel.org/linux-arm-kernel/1600332402-30123-1-git-send-email-anshuman.khandual@arm.com/ > > This mechanism focuses on the addressibility aspect and not [sub] section > alignment aspect. Hence check_hotplug_memory_range() and check_pfn_span() > have been left unchanged. Wondering if all these can still be unified in > an expanded memhp_range_allowed() check, that can be called from multiple > memory hot add and remove paths. > > This series applies on v5.10 and has been tested on arm64. But only > build tested on s390. > > Changes in V2: > > - Changed s390 version per Heiko and updated the commit message > - Called memhp_range_allowed() only for arch_add_memory() in pagemap_range() > - Exported the symbol memhp_get_pluggable_range() > > Changes in V1: > > https://lore.kernel.org/linux-mm/1607400978-31595-1-git-send-email-anshuman.khandual@arm.com/ > > - Fixed build problems with (MEMORY_HOTPLUG & !MEMORY_HOTREMOVE) > - Added missing prototype for arch_get_mappable_range() > - Added VM_BUG_ON() check for memhp_range_allowed() in arch_add_memory() per David > > Changes in RFC V2: > > https://lore.kernel.org/linux-mm/1606706992-26656-1-git-send-email-anshuman.khandual@arm.com/ > > Incorporated all review feedbacks from David. > > - Added additional range check in __segment_load() on s390 which was lost > - Changed is_private init in pagemap_range() > - Moved the framework into mm/memory_hotplug.c > - Made arch_get_addressable_range() a __weak function > - Renamed arch_get_addressable_range() as arch_get_mappable_range() > - Callback arch_get_mappable_range() only handles range requiring linear mapping > - Merged multiple memhp_range_allowed() checks in register_memory_resource() > - Replaced WARN() with pr_warn() in memhp_range_allowed() > - Replaced error return code ERANGE with E2BIG > > Changes in RFC V1: > > https://lore.kernel.org/linux-mm/1606098529-7907-1-git-send-email-anshuman.khandual@arm.com/ > > Cc: Heiko Carstens > Cc: Vasily Gorbik > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Ard Biesheuvel > Cc: Mark Rutland > Cc: David Hildenbrand > Cc: Andrew Morton > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-s390@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > > Anshuman Khandual (3): > mm/hotplug: Prevalidate the address range being added with platform > arm64/mm: Define arch_get_mappable_range() > s390/mm: Define arch_get_mappable_range() Thanks, I'm planning on reviewing + sending a virtio-mem patch to use memhp_get_mappable_range() in the new year. I assume we also have restrictions when it comes to x86-64, will have a look. -- Thanks, David / dhildenb