From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 0C4D16B29BD for ; Thu, 23 Aug 2018 07:10:27 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id w44-v6so2149950edb.16 for ; Thu, 23 Aug 2018 04:10:26 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id i59-v6si1675914edc.458.2018.08.23.04.10.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Aug 2018 04:10:25 -0700 (PDT) Date: Thu, 23 Aug 2018 13:10:24 +0200 From: Michal Hocko Subject: Re: A crash on ARM64 in move_freepages_block due to uninitialized pages in reserved memory Message-ID: <20180823111024.GC29735@dhcp22.suse.cz> References: <20180821104418.GA16611@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Mikulas Patocka Cc: James Morse , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Pavel Tatashin On Thu 23-08-18 07:02:37, Mikulas Patocka wrote: [...] > This crash is not from -ENOENT. It crashes because page->compound_head is > 0xffffffffffffffff (see below). > > If I enable CONFIG_DEBUG_VM, I also get VM_BUG. This smells like the struct page is not initialized properly. How is this memory range added? I mean is it brought up by the memory hotplug or during the boot? -- Michal Hocko SUSE Labs