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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 65673C4360F for ; Thu, 4 Apr 2019 13:11:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 20CA520855 for ; Thu, 4 Apr 2019 13:11:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="L8DH14U/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20CA520855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kD35+pe/N38TXpwdlWuJDNpe6/ikC2fdf971p8jA0iY=; b=L8DH14U/5AnWNo YuV/g7EJOWXO1omx5bCqaarcczMLfAL1RcQLFkfGpghOuNNz6xf7qD8zFHdOYjbegs0CFQal3UMhS r46jvc0iSBUv05l9f1oU3qjQJ750fJ56dXp+NlIwgcj02us4wx3l3XzOHxF0feN0jNvrTgU/WrH7m aKs6FLoF3JAdTJm62QtbcZWCz8NUpI/3BlvVSX33KwtxoNyIISRwRrIqNOEVsjNkQoICXXUFAK09W jZMtRqQ8AZdjAHN/x2GMoYUYlpdwtcxLo1b3fRvrfmth3+VJSr+e6YKF3rxK4lH63ZxTHGmxjSA2X GUk0spPxOuatD1jvYzig==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hC29b-000151-Fs; Thu, 04 Apr 2019 13:11:39 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hC29T-0000sq-6e for linux-arm-kernel@lists.infradead.org; Thu, 04 Apr 2019 13:11:35 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 38A17A78; Thu, 4 Apr 2019 06:11:29 -0700 (PDT) Received: from [10.162.40.100] (p8cg001049571a15.blr.arm.com [10.162.40.100]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CA5593F68F; Thu, 4 Apr 2019 06:11:23 -0700 (PDT) Subject: Re: [PATCH 0/6] arm64/mm: Enable memory hot remove and ZONE_DEVICE To: Dan Williams References: <1554265806-11501-1-git-send-email-anshuman.khandual@arm.com> From: Anshuman Khandual Message-ID: <6d46fc37-91e2-c44c-6e01-bfbd5c022f39@arm.com> Date: Thu, 4 Apr 2019 18:41:25 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190404_061131_907997_832E55AA X-CRM114-Status: GOOD ( 20.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Michal Hocko , David Hildenbrand , Catalin Marinas , cai@lca.pw, Will Deacon , Linux Kernel Mailing List , Pavel Tatashin , Linux MM , Logan Gunthorpe , james.morse@arm.com, cpandya@codeaurora.org, arunks@codeaurora.org, Andrew Morton , osalvador@suse.de, Mel Gorman , linux-arm-kernel@lists.infradead.org, Robin Murphy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 04/03/2019 11:38 PM, Dan Williams wrote: > On Tue, Apr 2, 2019 at 9:30 PM Anshuman Khandual > wrote: >> >> This series enables memory hot remove on arm64, fixes a memblock removal >> ordering problem in generic __remove_memory(), enables sysfs memory probe >> interface on arm64. It also enables ZONE_DEVICE with struct vmem_altmap >> support. >> >> Testing: >> >> Tested hot remove on arm64 for all 4K, 16K, 64K page config options with >> all possible VA_BITS and PGTABLE_LEVELS combinations. Tested ZONE_DEVICE >> with ARM64_4K_PAGES through a dummy driver. >> >> Build tested on non arm64 platforms. I will appreciate if folks can test >> arch_remove_memory() re-ordering in __remove_memory() on other platforms. >> >> Dependency: >> >> V5 series in the thread (https://lkml.org/lkml/2019/2/14/1096) will make >> kernel linear mapping loose pgtable_page_ctor() init. When this happens >> the proposed functions free_pte|pmd|pud_table() in [PATCH 2/6] will have >> to stop calling pgtable_page_dtor(). > > Hi Anshuman, Hello Dan, > > I'd be interested to integrate this with the sub-section hotplug > support [1]. Otherwise the padding implementation in libnvdimm can't > be removed unless all ZONE_DEVICE capable archs also agree on the > minimum arch_add_memory() granularity. I'd prefer not to special case > which archs support which granularity, but it unfortunately > complicates what you're trying to achieve. Sorry I have not been following your series on sub-section hotplug support. Hence might not have the full context here. Could you please give some more details on what exactly might be a problem. > > I think at a minimum we, mm hotplug co-travellers, need to come to a > consensus on whether sub-section support is viable for v5.2 and / or a > pre-requisite for new arch-ZONE_DEVICE implementations I would need to go through sub-section hotplug series first to understand the pre-requisite. Do we need to support sub-section hotplug first before being able to enable ZONE_DEVICE ? - Anshuman _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel