From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f45.google.com (mail-oi0-f45.google.com [209.85.218.45]) by kanga.kvack.org (Postfix) with ESMTP id 61AAF6B0038 for ; Mon, 19 Oct 2015 21:42:41 -0400 (EDT) Received: by oiao187 with SMTP id o187so1741611oia.3 for ; Mon, 19 Oct 2015 18:42:41 -0700 (PDT) Received: from szxga01-in.huawei.com (szxga01-in.huawei.com. [58.251.152.64]) by mx.google.com with ESMTPS id q65si298711oif.110.2015.10.19.18.42.39 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 19 Oct 2015 18:42:40 -0700 (PDT) Message-ID: <56259BFF.1090203@huawei.com> Date: Tue, 20 Oct 2015 09:42:23 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH] mm: Introduce kernelcore=reliable option References: <1444915942-15281-1-git-send-email-izumi.taku@jp.fujitsu.com> <5624548F.30500@huawei.com> In-Reply-To: Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Izumi, Taku" Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "tony.luck@intel.com" , "Kamezawa, Hiroyuki" , "mel@csn.ul.ie" , "akpm@linux-foundation.org" , "dave.hansen@intel.com" , "matt@codeblueprint.co.uk" On 2015/10/20 8:34, Izumi, Taku wrote: > Hi Xishi, > >> On 2015/10/15 21:32, Taku Izumi wrote: >> >>> Xeon E7 v3 based systems supports Address Range Mirroring >>> and UEFI BIOS complied with UEFI spec 2.5 can notify which >>> ranges are reliable (mirrored) via EFI memory map. >>> Now Linux kernel utilize its information and allocates >>> boot time memory from reliable region. >>> >>> My requirement is: >>> - allocate kernel memory from reliable region >>> - allocate user memory from non-reliable region >>> >>> In order to meet my requirement, ZONE_MOVABLE is useful. >>> By arranging non-reliable range into ZONE_MOVABLE, >>> reliable memory is only used for kernel allocations. >>> >>> This patch extends existing "kernelcore" option and >>> introduces kernelcore=reliable option. By specifying >>> "reliable" instead of specifying the amount of memory, >>> non-reliable region will be arranged into ZONE_MOVABLE. >>> >>> Earlier discussion is at: >>> https://lkml.org/lkml/2015/10/9/24 >>> >> >> Hi Taku, >> >> If user don't want to waste a lot of memory, and he only set >> a few memory to mirrored memory, then the kernelcore is very >> small, right? That means OS will have a very small normal zone >> and a very large movable zone. > > Right. > >> Kernel allocation could only use the unmovable zone. As the >> normal zone is very small, the kernel allocation maybe OOM, >> right? > > Right. > >> Do you mean that we will reuse the movable zone in short-term >> solution and create a new zone(mirrored zone) in future? > > If there is that kind of requirements, I don't oppose > creating a new zone. > As far as I know, some apps(e.g. date base) maybe could only use the normal zone. Thanks, Xishi Qiu > Sincerely, > Taku Izumi > > . > -- 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