Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753048AbbLIV7U (ORCPT ); Wed, 9 Dec 2015 16:59:20 -0500 Received: from mga09.intel.com ([134.134.136.24]:38727 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752123AbbLIV7T convert rfc822-to-8bit (ORCPT ); Wed, 9 Dec 2015 16:59:19 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,405,1444719600"; d="scan'208";a="870366851" From: "Luck, Tony" To: Xishi Qiu , Taku Izumi CC: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "kamezawa.hiroyu@jp.fujitsu.com" , "mel@csn.ul.ie" , "Hansen, Dave" , "matt@codeblueprint.co.uk" Subject: RE: [PATCH v3 2/2] mm: Introduce kernelcore=mirror option Thread-Topic: [PATCH v3 2/2] mm: Introduce kernelcore=mirror option Thread-Index: AQHRMjAhAQ0e9br7T0uYMif+yG96M57ChRIAgACu/pA= Date: Wed, 9 Dec 2015 21:59:17 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F39F7F4CD@ORSMSX114.amr.corp.intel.com> References: <1449631109-14756-1-git-send-email-izumi.taku@jp.fujitsu.com> <1449631177-14863-1-git-send-email-izumi.taku@jp.fujitsu.com> <56679FDC.1080800@huawei.com> In-Reply-To: <56679FDC.1080800@huawei.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsIiwiaWQiOiI4ZTkyMWYzNi1kZTk3LTRiZGEtYTM1YS1jNjVhZGNhN2QxNGQiLCJwcm9wcyI6W3sibiI6IkludGVsRGF0YUNsYXNzaWZpY2F0aW9uIiwidmFscyI6W3sidmFsdWUiOiJDVFBfSUMifV19XX0sIlN1YmplY3RMYWJlbHMiOltdLCJUTUNWZXJzaW9uIjoiMTUuNC4xMC4xOSIsIlRydXN0ZWRMYWJlbEhhc2giOiJjdmpYWGhDbCtxQXZNOUxFWlwva20rbks0MFBGbzFKQ3NmazB4R0ZjbEpOZz0ifQ== x-inteldataclassification: CTP_IC x-originating-ip: [10.22.254.138] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 865 Lines: 19 > How about add some comment, if mirrored memroy is too small, then the > normal zone is small, so it may be oom. > The mirrored memory is at least 1/64 of whole memory, because struct > pages usually take 64 bytes per page. 1/64th is the absolute lower bound (for the page structures as you say). I expect people will need to configure 10% or more to run any real workloads. I made the memblock boot time allocator fall back to non-mirrored memory if mirrored memory ran out. What happens in the run time allocator if the non-movable zones run out of pages? Will we allocate kernel pages from movable memory? -Tony -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/