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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 81E49C433E9 for ; Mon, 11 Jan 2021 10:53:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47BC8221ED for ; Mon, 11 Jan 2021 10:53:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729566AbhAKKxX (ORCPT ); Mon, 11 Jan 2021 05:53:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:23417 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729306AbhAKKxV (ORCPT ); Mon, 11 Jan 2021 05:53:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610362314; 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=dw2Go3odg3xQMi8oKZf9V/+2r4MBnUAd+QSYJ2Ro4mk=; b=VFEF7adGCxt5rRD3DiV6/2isRp278+qFdI+tbiI4JgMtOVhNEMjPPu7ou0f1q3aAt4AVOr OQ6lqqGoPLknSraCae98xMuJkSI729nqAzclD+/AwEwCUdar5K/iQVG7TeFzgD/XX9DIrR g7yfE9Dqsb9X+AfIizE/TElCiH1OUhQ= 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-482-94NqtCM0NF23H57DTgUYyg-1; Mon, 11 Jan 2021 05:51:52 -0500 X-MC-Unique: 94NqtCM0NF23H57DTgUYyg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E87FF180A09F; Mon, 11 Jan 2021 10:51:50 +0000 (UTC) Received: from [10.36.115.103] (ovpn-115-103.ams2.redhat.com [10.36.115.103]) by smtp.corp.redhat.com (Postfix) with ESMTP id 94DC274AAC; Mon, 11 Jan 2021 10:51:48 +0000 (UTC) Subject: Re: [PATCH V2 1/3] mm/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: 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> <1608218912-28932-2-git-send-email-anshuman.khandual@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <10e733fa-4568-d38f-9b95-2ccc5dc627b8@redhat.com> Date: Mon, 11 Jan 2021 11:51:47 +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: <1608218912-28932-2-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 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.12.20 16:28, 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 > ensure that the range has been validated with memhp_range_allowed() earlier > in the call chain. Besides memhp_get_pluggable_range() also can be used by > potential memory hotplug callers to avail the allowed physical range which > would go through on a given platform. > > This does not really add any new range check in generic memory hotplug but > instead compensates for lost checks in arch_add_memory() where applicable > and check_hotplug_memory_addressable(), with unified memhp_range_allowed(). > Subject s/mm\/hotplug/mm\/memory_hotplug/ Everywhere in this patch: Use "true/false" for boolean values. > Cc: David Hildenbrand > Cc: Andrew Morton > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Suggested-by: David Hildenbrand > Signed-off-by: Anshuman Khandual > --- > include/linux/memory_hotplug.h | 10 +++++ > mm/memory_hotplug.c | 79 +++++++++++++++++++++++++--------- > mm/memremap.c | 6 +++ > 3 files changed, 75 insertions(+), 20 deletions(-) > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index 551093b74596..8d72354758c8 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -70,6 +70,9 @@ typedef int __bitwise mhp_t; > */ > #define MEMHP_MERGE_RESOURCE ((__force mhp_t)BIT(0)) > > +bool memhp_range_allowed(u64 start, u64 size, bool need_mapping); > +struct range memhp_get_pluggable_range(bool need_mapping); AFAIKs, all memhp_get_pluggable_range() users pass "1". What about the "add_pages()-only" path? -- Thanks, David / dhildenb