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=-7.4 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_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 5393AC433E0 for ; Tue, 19 Jan 2021 12:22:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CF19523104 for ; Tue, 19 Jan 2021 12:22:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF19523104 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CD4A96B00C2; Tue, 19 Jan 2021 07:22:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C84A86B00F7; Tue, 19 Jan 2021 07:22:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B9BB66B0105; Tue, 19 Jan 2021 07:22:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0199.hostedemail.com [216.40.44.199]) by kanga.kvack.org (Postfix) with ESMTP id A4A846B00C2 for ; Tue, 19 Jan 2021 07:22:05 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6083C180AD801 for ; Tue, 19 Jan 2021 12:22:05 +0000 (UTC) X-FDA: 77722436610.20.truck12_290d99b27551 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 416C3180C07AB for ; Tue, 19 Jan 2021 12:22:05 +0000 (UTC) X-HE-Tag: truck12_290d99b27551 X-Filterd-Recvd-Size: 3846 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf39.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 Jan 2021 12:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611058924; 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=N/Ldn6cKgGuq/aEJMSquo67YjjGGoJdj7Dnv+qTpdTU=; b=fuU5WUcHJeuSQIPiLgvtprQ2o9f2Ft8RpmnonPR2eZvaV5OI+Jny3C6m7k0tLHIfle1Y8F SKNdjXAcC6b41k2aGfVJC5+o83BY6op6A2UstzxT84I3xEMYLKmI3nWuMDh7pkr1dGMMGC rUYaOUaXdwcPcC//JCCbsr91QtbWROA= 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-419-IRQ3jEvWNeCuH6cJJWotVg-1; Tue, 19 Jan 2021 07:21:59 -0500 X-MC-Unique: IRQ3jEvWNeCuH6cJJWotVg-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 137AC107ACE8; Tue, 19 Jan 2021 12:21:57 +0000 (UTC) Received: from [10.36.114.143] (ovpn-114-143.ams2.redhat.com [10.36.114.143]) by smtp.corp.redhat.com (Postfix) with ESMTP id 671E260BF1; Tue, 19 Jan 2021 12:21:54 +0000 (UTC) Subject: Re: [PATCH V3 1/3] mm/memory_hotplug: Prevalidate the address range being added with platform To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com Cc: Oscar Salvador , Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> <1610975582-12646-2-git-send-email-anshuman.khandual@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <691872bb-b251-83e0-126e-afd54683c83e@redhat.com> Date: Tue, 19 Jan 2021 13:21:53 +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: <1610975582-12646-2-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 10.5.11.12 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 18.01.21 14:12, Anshuman Khandual wrote: > This introduces memhp_range_allowed() which can be called in various memory > hotplug paths to prevalidate the address range which is being added, with > the platform. Then memhp_range_allowed() calls memhp_get_pluggable_range() > which provides applicable address range depending on whether linear mapping > is required or not. For ranges that require linear mapping, it calls a new > arch callback arch_get_mappable_range() which the platform can override. So > the new callback, in turn provides the platform an opportunity to configure > acceptable memory hotplug address ranges in case there are constraints. > > This mechanism will help prevent platform specific errors deep down during > hotplug calls. This drops now redundant check_hotplug_memory_addressable() > check in __add_pages() but instead adds a VM_BUG_ON() check which would In this patch, you keep the __add_pages() checks. But as discussed, we could perform it in mm/memremap.c:pagemap_range() insted and convert it to a VM_BUG_ON(). Apart from that looks good to me. -- Thanks, David / dhildenb