Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751624AbbLJFht (ORCPT ); Thu, 10 Dec 2015 00:37:49 -0500 Received: from mgwkm01.jp.fujitsu.com ([202.219.69.168]:52548 "EHLO mgwkm01.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751041AbbLJFhr (ORCPT ); Thu, 10 Dec 2015 00:37:47 -0500 From: "Izumi, Taku" To: Xishi Qiu , "Luck, Tony" CC: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "Kamezawa, Hiroyuki" , "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: AQHRMjAR2Z6g1ySguUa1IzGGIcYfOZ7BaBYAgAE2XICAADaQAIAAt+Yw Date: Thu, 10 Dec 2015 05:37:41 +0000 Message-ID: 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> <3908561D78D1C84285E8C5FCA982C28F39F7F4CD@ORSMSX114.amr.corp.intel.com> <5668D1FA.4050108@huawei.com> In-Reply-To: <5668D1FA.4050108@huawei.com> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-securitypolicycheck: OK by SHieldMailChecker v2.3.2 x-shieldmailcheckerpolicyversion: FJ-ISEC-20150624-1 x-shieldmailcheckermailid: ec2f5c7e183346a98a4948809696004c x-originating-ip: [10.124.102.50] Content-Type: text/plain; charset="iso-2022-jp" MIME-Version: 1.0 X-SecurityPolicyCheck-GC: OK by FENCE-Mail X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1479 Lines: 44 Dear Tony, Xishi, > >> 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? > > > > As I know, the kernel pages will not allocated from movable zone. Yes, kernel pages are not allocated from ZONE_MOVABLE. In this case administrator must review and reconfigure the mirror ratio via "MirrorRequest" EFI variable. Sincerely, Taku Izumi > > > -- > > 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/ > > > > . > > > > -- 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/