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=-7.5 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 B077DC433DB for ; Wed, 20 Jan 2021 10:42:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4B1D323332 for ; Wed, 20 Jan 2021 10:42:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B1D323332 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 BDA5D6B0007; Wed, 20 Jan 2021 05:42:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B636C6B0008; Wed, 20 Jan 2021 05:42:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A2C3F6B000A; Wed, 20 Jan 2021 05:42:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 871426B0007 for ; Wed, 20 Jan 2021 05:42:04 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 4FDC98249980 for ; Wed, 20 Jan 2021 10:42:04 +0000 (UTC) X-FDA: 77725813368.08.space42_0306b3b27559 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 2959C1819E627 for ; Wed, 20 Jan 2021 10:42:04 +0000 (UTC) X-HE-Tag: space42_0306b3b27559 X-Filterd-Recvd-Size: 4375 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf50.hostedemail.com (Postfix) with ESMTP for ; Wed, 20 Jan 2021 10:42:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611139323; 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=PWzE1S6HXNzVdjyh7DmP7VYe4VGerymzd4mGWS9FWcU=; b=AlWIuuDQdEoKC+BDprVhw96M33lmt+GkcBWuyHNcPYPwm7lSk1aqC10p8aW3ZFaFB+7PkN nwh9gPw+jStDhHBHdosHd6Ao7wO2czgQ269NR4O7jYWDi4JbuHNRnc699cXNJ5k1JEgxmT 47EyXLBAbZ8PRZN4STPs2ecl62X6IME= 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-10-B2hc1i0KOzOdQmQlesWZ8A-1; Wed, 20 Jan 2021 05:41:59 -0500 X-MC-Unique: B2hc1i0KOzOdQmQlesWZ8A-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 050361800D42; Wed, 20 Jan 2021 10:41:57 +0000 (UTC) Received: from [10.36.115.161] (ovpn-115-161.ams2.redhat.com [10.36.115.161]) by smtp.corp.redhat.com (Postfix) with ESMTP id 402905D74B; Wed, 20 Jan 2021 10:41:54 +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> <691872bb-b251-83e0-126e-afd54683c83e@redhat.com> <3d4f3b14-0715-b2b3-b015-04b8a77abfb8@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <30bbf862-06a4-bd1d-b902-61aa4183b819@redhat.com> Date: Wed, 20 Jan 2021 11:41:53 +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: <3d4f3b14-0715-b2b3-b015-04b8a77abfb8@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 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 20.01.21 09:33, Anshuman Khandual wrote: > > > On 1/19/21 5:51 PM, David Hildenbrand wrote: >> 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(). > > Just to be sure, will the following change achieve what you are > suggesting here. pagemap_range() after this change, will again > be the same like the V1 series. Yeah, as we used to have in v1. Maybe other reviewers (@Oscar?) have a different opinion. If you decide to leave as-is, please fixup the patch description. Thanks! -- Thanks, David / dhildenb