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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, 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 81A0DC433E0 for ; Fri, 12 Feb 2021 10:18:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5002964E14 for ; Fri, 12 Feb 2021 10:18:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230433AbhBLKSK (ORCPT ); Fri, 12 Feb 2021 05:18:10 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59586 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229959AbhBLKSF (ORCPT ); Fri, 12 Feb 2021 05:18:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613124999; 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=K89LA8Ozpxu/REPXjq8jdde5J4XMhRa6v2Bjz/+EfdE=; b=hltD04bbzSQM1rj+UyKrK27o48wWB/aJ6qFml2SOcmHTLOY8xCgIiUzzXYgiIj/6GyUarB m+XhDOP5Plzq+I0FNh8COE5Rjt0mi+lkixUK/mjgP4F/DTYtGhw/fZAVcaIBalb/Zc8DmF WFZfLEybD5nKW6CTHEsgr3jKl8gWaSo= 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-31-vkweBHaqPKi87kqAwe3uCw-1; Fri, 12 Feb 2021 05:16:35 -0500 X-MC-Unique: vkweBHaqPKi87kqAwe3uCw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EF137801962; Fri, 12 Feb 2021 10:16:32 +0000 (UTC) Received: from [10.36.114.178] (ovpn-114-178.ams2.redhat.com [10.36.114.178]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D34B1F456; Fri, 12 Feb 2021 10:16:28 +0000 (UTC) Subject: Re: [PATCH v5 1/1] mm: refactor initialization of struct page for holes in memory layout To: Michal Hocko Cc: Mike Rapoport , Andrew Morton , Andrea Arcangeli , Baoquan He , Borislav Petkov , Chris Wilson , "H. Peter Anvin" , Ingo Molnar , Linus Torvalds , =?UTF-8?Q?=c5=81ukasz_Majczak?= , Mel Gorman , Mike Rapoport , Qian Cai , "Sarvela, Tomi P" , Thomas Gleixner , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, x86@kernel.org References: <20210208110820.6269-1-rppt@kernel.org> <5dccbc93-f260-7f14-23bc-6dee2dff6c13@redhat.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <1523f1a6-41be-1fc7-08b9-b777a5b4ef24@redhat.com> Date: Fri, 12 Feb 2021 11:16:28 +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: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12.02.21 11:11, Michal Hocko wrote: > On Fri 12-02-21 10:56:19, David Hildenbrand wrote: >> On 12.02.21 10:55, David Hildenbrand wrote: >>> On 08.02.21 12:08, Mike Rapoport wrote: > [...] >>>> @@ -6519,8 +6581,19 @@ void __init get_pfn_range_for_nid(unsigned int nid, >>>> *end_pfn = max(*end_pfn, this_end_pfn); >>>> } >>>> - if (*start_pfn == -1UL) >>>> + if (*start_pfn == -1UL) { >>>> *start_pfn = 0; >>>> + return; >>>> + } >>>> + >>>> +#ifdef CONFIG_SPARSEMEM >>>> + /* >>>> + * Sections in the memory map may not match actual populated >>>> + * memory, extend the node span to cover the entire section. >>>> + */ >>>> + *start_pfn = round_down(*start_pfn, PAGES_PER_SECTION); >>>> + *end_pfn = round_up(*end_pfn, PAGES_PER_SECTION); >>> >>> Does that mean that we might create overlapping zones when one node >> >> s/overlapping zones/overlapping nodes/ > > I didn't get to review the patch yet. Just wanted to note that we can > interleave nodes/zone. Or what kind of concern do you have in mind? I know that we can have it after boot, when hotplugging memory. How about during boot? For example, which node will a PFN then actually be assigned to? I was just wondering if this might result in issues - if that can already happen, then it's just fine I guess. -- Thanks, David / dhildenb