From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:25158 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726162AbgLBUgf (ORCPT ); Wed, 2 Dec 2020 15:36:35 -0500 Date: Wed, 2 Dec 2020 21:35:40 +0100 From: Heiko Carstens Subject: Re: [RFC V2 0/3] mm/hotplug: Pre-validate the address range with platform Message-ID: <20201202203540.GC11274@osiris> References: <1606706992-26656-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1606706992-26656-1-git-send-email-anshuman.khandual@arm.com> List-ID: To: Anshuman Khandual Cc: linux-mm@kvack.org, akpm@linux-foundation.org, david@redhat.com, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland On Mon, Nov 30, 2020 at 08:59:49AM +0530, 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-rc6 and has been slightly tested on arm64. > But looking for some early feedback here. > > Changes in RFC V2: > > 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 Btw. please use git send-email's --cc-cover option to make sure that all patches of this series will be sent to all listed cc's. I really dislike to receive only the cover-letter and maybe on patch and then have to figure out where to find the rest. Thanks :)