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=-5.6 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 32C69C433E7 for ; Sat, 17 Oct 2020 09:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D409A2074A for ; Sat, 17 Oct 2020 09:36:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MgYxuAxR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437799AbgJQJgt (ORCPT ); Sat, 17 Oct 2020 05:36:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:44915 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437763AbgJQJgt (ORCPT ); Sat, 17 Oct 2020 05:36:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602927407; 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=56DeDJ546FnlLJEUXisq/vRqsIQGDX0v5Ga48J4Hjlg=; b=MgYxuAxRHGzGmwr5gMH9BKBBcSM1Vy1DjJqd3F+OH7+vl/s0XXxTj7H9m6u1XJuK59A4BS b00wsOWw4UHby05AoppA1Vbsk3JjBiiwZnM7nhTOJIkTiUug1j/2r6mnkAD4u2ONSjBNgN jvHhtqcejClOm5sV/RnC1kQqGXHy3Bs= 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-542-NdvBizmWN6O4WjHIbSM9Pw-1; Sat, 17 Oct 2020 05:36:43 -0400 X-MC-Unique: NdvBizmWN6O4WjHIbSM9Pw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0A0B757053; Sat, 17 Oct 2020 09:36:42 +0000 (UTC) Received: from [10.36.112.50] (ovpn-112-50.ams2.redhat.com [10.36.112.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id F34E81002C00; Sat, 17 Oct 2020 09:36:39 +0000 (UTC) Subject: Re: [PATCH 1/2] mm/memory_hotplug: allow marking of memory sections as hotpluggable To: Mike Rapoport , Sudarshan Rajagopalan Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , Anshuman Khandual , Mark Rutland , Steven Price , Logan Gunthorpe , Suren Baghdasaryan References: <2cba881c51e42cfe5ba213e09273642136e8ef93.1602899443.git.sudaraja@codeaurora.org> <20201017082600.GB16395@kernel.org> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <51333360-bcf6-0d21-923c-ce8aca4c8719@redhat.com> Date: Sat, 17 Oct 2020 11:36:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201017082600.GB16395@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.10.20 10:26, Mike Rapoport wrote: > On Fri, Oct 16, 2020 at 07:02:23PM -0700, Sudarshan Rajagopalan wrote: >> Certain architectures such as arm64 doesn't allow boot memory to be >> offlined and removed. Distinguish certain memory sections as >> "hotpluggable" which can be marked by module drivers stating to memory >> hotplug layer that these sections can be offlined and then removed. > > I don't quite follow why marking sections as hotpluggable or not should > be done by a device driver. Can you describe in more details your > use-case and why there is a need to add a flag to the memory map? > This seems to be related to https://lkml.kernel.org/r/de8388df2fbc5a6a33aab95831ba7db4@codeaurora.org After reading how the driver is trying to abuse memory hot(un)plug infrastructure, my tentative Nacked-by: David Hildenbrand -- Thanks, David / dhildenb