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=-7.5 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 D5D51C433DB for ; Mon, 4 Jan 2021 15:45:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA2B32245C for ; Mon, 4 Jan 2021 15:45:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727265AbhADPpX (ORCPT ); Mon, 4 Jan 2021 10:45:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:28800 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726098AbhADPpW (ORCPT ); Mon, 4 Jan 2021 10:45:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1609775036; 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=F64o4iIcbY4ifKBh0Jo3J+CYfbSeoigrg9hqqLOwqkU=; b=dODK93bDmhDbC6RAwL+kOkoDNE3/DIUPsWZWtzz2PpDdA6Y5kQofVbQYgteAeohVMtDfkV or+Rrx9Auyhzc/Nqsi9g2UQFzvA3eUd305NoW+D0h4c/Vn60TWO9kGQOEyGVHbHfuvccg+ 6qb/Y34DJkT1zD44snc/JsqkZdXET24= 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-278-pAlaefTrMouQlR9f8BSXzw-1; Mon, 04 Jan 2021 10:43:52 -0500 X-MC-Unique: pAlaefTrMouQlR9f8BSXzw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 553FAC281; Mon, 4 Jan 2021 15:43:51 +0000 (UTC) Received: from [10.36.114.59] (ovpn-114-59.ams2.redhat.com [10.36.114.59]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E95960BFA; Mon, 4 Jan 2021 15:43:50 +0000 (UTC) Subject: Re: uninitialized pmem struct pages To: Michal Hocko Cc: Dan Williams , linux-mm@kvack.org, LKML , Oscar Salvador References: <20210104100323.GC13207@dhcp22.suse.cz> <033e1cd6-9762-5de6-3e88-47d3038fda7f@redhat.com> <20210104142624.GI13207@dhcp22.suse.cz> <23a4eea2-9fdb-fd1d-ee92-9cd8ac6e8f41@redhat.com> <20210104151005.GK13207@dhcp22.suse.cz> <26db2c3e-10c7-c6e3-23f7-21eb5101b31a@redhat.com> <20210104153300.GL13207@dhcp22.suse.cz> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Mon, 4 Jan 2021 16:43:49 +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: <20210104153300.GL13207@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04.01.21 16:33, Michal Hocko wrote: > On Mon 04-01-21 16:15:23, David Hildenbrand wrote: >> On 04.01.21 16:10, Michal Hocko wrote: > [...] >> Do the physical addresses you see fall into the same section as boot >> memory? Or what's around these addresses? > > Yes I am getting a garbage for the first struct page belonging to the > pmem section [1] > [ 0.020161] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x603fffffff] > [ 0.020163] ACPI: SRAT: Node 4 PXM 4 [mem 0x6060000000-0x11d5fffffff] non-volatile > > The pfn without the initialized struct page is 0x6060000. This is a > first pfn in a section. Okay, so we're not dealing with the "early section" mess I described, different story. Due to [1], is_mem_section_removable() called pfn_to_page(PHYS_PFN(0x6060000)). page_zone(page) made it crash, as not initialized. Let's assume this is indeed a reserved pfn in the altmap. What's the actual address of the memmap? I do wonder what hosts pfn_to_page(PHYS_PFN(0x6060000)) - is it actually part of the actual altmap (i.e. > 0x6060000) or maybe even self-hosted? If it's not self-hosted, initializing the relevant memmaps should work just fine I guess. Otherwise things get more complicated. -- Thanks, David / dhildenb