From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f41.google.com (mail-pa0-f41.google.com [209.85.220.41]) by kanga.kvack.org (Postfix) with ESMTP id 167B36B0254 for ; Thu, 22 Oct 2015 06:02:54 -0400 (EDT) Received: by pacfv9 with SMTP id fv9so86967638pac.3 for ; Thu, 22 Oct 2015 03:02:53 -0700 (PDT) Received: from mgwkm03.jp.fujitsu.com (mgwkm03.jp.fujitsu.com. [202.219.69.170]) by mx.google.com with ESMTPS id l11si19914221pbq.245.2015.10.22.03.02.52 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Oct 2015 03:02:53 -0700 (PDT) Received: from m3051.s.css.fujitsu.com (m3051.s.css.fujitsu.com [10.134.21.209]) by kw-mxoi1.gw.nic.fujitsu.com (Postfix) with ESMTP id DEF25AC00D9 for ; Thu, 22 Oct 2015 19:02:44 +0900 (JST) Subject: Re: [PATCH] mm: Introduce kernelcore=reliable option References: <1444915942-15281-1-git-send-email-izumi.taku@jp.fujitsu.com> <3908561D78D1C84285E8C5FCA982C28F32B5A060@ORSMSX114.amr.corp.intel.com> From: Kamezawa Hiroyuki Message-ID: <5628B427.3050403@jp.fujitsu.com> Date: Thu, 22 Oct 2015 19:02:15 +0900 MIME-Version: 1.0 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F32B5A060@ORSMSX114.amr.corp.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Luck, Tony" , Taku Izumi , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Cc: "qiuxishi@huawei.com" , "mel@csn.ul.ie" , "akpm@linux-foundation.org" , "Hansen, Dave" , "matt@codeblueprint.co.uk" On 2015/10/22 3:17, Luck, Tony wrote: > + if (reliable_kernelcore) { > + for_each_memblock(memory, r) { > + if (memblock_is_mirror(r)) > + continue; > > Should we have a safety check here that there is some mirrored memory? If you give > the kernelcore=reliable option on a machine which doesn't have any mirror configured, > then we'll mark all memory as removable. You're right. > What happens then? Do kernel allocations fail? Or do they fall back to using removable memory? Maybe the kernel cannot boot because NORMAL zone is empty. > Is there a /proc or /sys file that shows the current counts for the removable zone? I just > tried this patch with a high percentage of memory marked as mirror ... but I'd like to see > how much is actually being used to tune things a bit. > I think /proc/zoneinfo can show detailed numbers per zone. Do we need some for meminfo ? Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org