From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751091AbdL1QBu (ORCPT ); Thu, 28 Dec 2017 11:01:50 -0500 Received: from mail-eopbgr40135.outbound.protection.outlook.com ([40.107.4.135]:21413 "EHLO EUR03-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750747AbdL1QBr (ORCPT ); Thu, 28 Dec 2017 11:01:47 -0500 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=aryabinin@virtuozzo.com; Subject: Re: [lkp-robot] [x86/cpu_entry_area] 10043e02db: kernel_BUG_at_arch/x86/mm/physaddr.c To: Dmitry Vyukov , Thomas Gleixner Cc: kernel test robot , Ingo Molnar , Andy Lutomirski , Boris Ostrovsky , Borislav Petkov , Brian Gerst , Dave Hansen , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , "H. Peter Anvin" , Josh Poimboeuf , Juergen Gross , Linus Torvalds , Peter Zijlstra , Will Deacon , LKML , tipbuild@zytor.com, LKP , Alexander Potapenko , kasan-dev References: <20171226020335.GA3172@yexl-desktop> From: Andrey Ryabinin Message-ID: <5cac9d39-dc2e-e671-cd16-ad32e014fd27@virtuozzo.com> Date: Thu, 28 Dec 2017 19:01:41 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [195.214.232.6] X-ClientProxiedBy: HE1PR0701CA0053.eurprd07.prod.outlook.com (2603:10a6:3:9e::21) To HE1PR08MB2825.eurprd08.prod.outlook.com (2603:10a6:7:2e::24) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 9fe2e0d2-14f4-41e1-2701-08d54e0c4906 X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(4534020)(4602075)(7168020)(4627115)(201703031133081)(201702281549075)(5600026)(4604075)(2017052603307)(7153060);SRVR:HE1PR08MB2825; 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But I guess it runs into a corner case where 1/8 is somehow > larger than 1 :) > We may simply don't have 1/8 available. And we actually need slightly more than 1/8. Kernel image is present in 2 locations (direct mapping/kernel mapping) so at least ram/8 + kernel_size/8. The same for cpu_entry_area. Plus some memory to build page tables. And note that kernel_size could be hundreds of megabytes.