From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F909C433F5 for ; Wed, 9 Mar 2022 16:05:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 729E48D0002; Wed, 9 Mar 2022 11:05:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6B1548D0001; Wed, 9 Mar 2022 11:05:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 551DF8D0002; Wed, 9 Mar 2022 11:05:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id 4217F8D0001 for ; Wed, 9 Mar 2022 11:05:30 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id F17DE181AC217 for ; Wed, 9 Mar 2022 16:05:29 +0000 (UTC) X-FDA: 79225322778.26.6977787 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP id 14783C0016 for ; Wed, 9 Mar 2022 16:05:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description; bh=qzB5SkChcUpXXTILPYEoiZsWblCS3kRjEhEA4tvWFBA=; b=JjBfU4RcbAJyJTf1dScNeR/9Ho AlZkTmpj9SsK1oDq6UTB/AcWUopsbiSLBGR6rZ2kBCw7j4vNo2VJRBUq8/KFhsm1GawDk4dDcSTB0 CAcF6dfoPaEs0Gfz8X8csw4+TvxgiPIlR30lPYJvaOwQCM8VvYdi8Wsr4XICpNu/Qaygh0PysniQO SyyGMm6lUhw5iTcltD/IOCdeqX++6/j+K96Pdx2bmwdewbe3c6YDhA7DoYvB3PWynCjiFTZ95BR6a cfwFLvgkagvPcfT8tRBkxAXjKWBSrNNRFeT2Lc3lff5pJIccLtnRTXiKaaapODICmEkZ+Gvc9/379 brxt0HAQ==; Received: from [2601:1c0:6280:3f0::aa0b] by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRyoJ-00HGIW-9U; Wed, 09 Mar 2022 16:05:11 +0000 Message-ID: Date: Wed, 9 Mar 2022 08:05:05 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH] docs/kernel-parameters: update description of mem= Content-Language: en-US To: Mike Rapoport , Jonathan Corbet Cc: Andrew Morton , "Maciej W. Rozycki" , Mike Rapoport , Tiezhu Yang , Thomas Bogendoerfer , linux-doc@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220309122446.1118738-1-rppt@kernel.org> From: Randy Dunlap In-Reply-To: <20220309122446.1118738-1-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: a76nqhpbckbmnk68fc7ax6twybht7iwa Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=JjBfU4Rc; spf=none (imf10.hostedemail.com: domain of rdunlap@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=rdunlap@infradead.org; dmarc=none X-Rspamd-Queue-Id: 14783C0016 X-HE-Tag: 1646841928-276859 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Mike, On 3/9/22 04:24, Mike Rapoport wrote: > From: Mike Rapoport > > The existing description of mem= does not cover all the cases and > differences between how architectures treat it. > > Extend the description to match the code. > > Signed-off-by: Mike Rapoport > --- > > This is in a way a followup for the discussion of mem= usage on MIPS: > > https://lore.kernel.org/all/1646461289-31992-1-git-send-email-yangtiezhu@loongson.cn > > .../admin-guide/kernel-parameters.txt | 20 +++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index f5a27f067db9..f3597841a031 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2834,6 +2834,15 @@ > 2 when the kernel is not able to see the whole system memory; > 3 memory that lies after 'mem=' boundary is excluded from > the hypervisor, then assigned to KVM guests. > + 4 to limit the memory available for kdump kernel. > + > + [ARC,MICROBLAZE] - the limit applies only to low memory, > + high memory is not affected. > + > + [ARM64] - only limits memory covered by the linear > + mapping. The NOMAP regions are not affected. > + > + [HEXAGON] - must be use to set the memory size, there is Above line seems to be missing something? Otherwise looks good AFAIK. > > [X86] Work as limiting max address. Use together > with memmap= to avoid physical address space collisions. > @@ -2844,6 +2853,17 @@ > in above case 3, memory may need be hot added after boot > if system memory of hypervisor is not sufficient. > > + mem=nn[KMG]@ss[KMG] > + [ARM,MIPS] - override the memory layout reported by > + firmware. > + Define a memory region of size nn[KMG] starting at > + ss[KMG]. > + Multiple different regions can be specified with > + multiple mem= parameters on the command line. > + > + mem=nn[KMG] [HEXAGON] Set the memory size. > + Must be specified, otherwise memory size will be 0. > + > mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel > memory. > -- ~Randy