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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71C82C433F5 for ; Wed, 9 Mar 2022 17:23:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236990AbiCIRYU (ORCPT ); Wed, 9 Mar 2022 12:24:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237044AbiCIRYH (ORCPT ); Wed, 9 Mar 2022 12:24:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C29782D01; Wed, 9 Mar 2022 09:23:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 794F361073; Wed, 9 Mar 2022 17:23:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A497C340E8; Wed, 9 Mar 2022 17:23:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646846586; bh=mSXOxDm0YQ/4bRgksAVQhm0M51442VyGvpFWc/rjdAg=; h=From:To:Cc:Subject:Date:From; b=hwmGntSJzO+BOdWggrE8RO+wwrUWI5gbLemWvf6pRnlLQT3jdEGQn6/I2fNO0Kahh 4PwGFv0QZsr/4eNoxgttSNHt0mCaU1IaxO8rRyXD0E7UeZ+WgRTErF193RDDP4c10h Efh3Akk9SCJYaK020CxPZrQlmQCGLsI2kGwi6ThM0rJoGgrJjPOKT9Ym/SMeediYrx AmCoB6t3UphglNfOrXN96U+9h1bIakCmmGCuaDafwuHFGtZTYtagakME47Gm9HHerH dN+CBm5CnUaD1LpKhSNb8v5MaiJVTd6BMFjyBbP9o6lcqs3EaaBxq+i7Id9IGVbzxg vry6HNW6enpRg== From: Mike Rapoport To: Jonathan Corbet Cc: Andrew Morton , "Maciej W. Rozycki" , Mike Rapport , Mike Rapoport , Randy Dunlap , Sergey Shtylyov , Tiezhu Yang , Thomas Bogendoerfer , linux-doc@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] docs/kernel-parameters: update description of mem= Date: Wed, 9 Mar 2022 19:22:58 +0200 Message-Id: <20220309172258.1183796-1-rppt@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- v1: https://lore.kernel.org/all/20220309122446.1118738-1-rppt@kernel.org * drop clumsy and redundant paragraph about Hexagon .../admin-guide/kernel-parameters.txt | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f5a27f067db9..40cd4136331b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2834,6 +2834,13 @@ 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. [X86] Work as limiting max address. Use together with memmap= to avoid physical address space collisions. @@ -2844,6 +2851,17 @@ 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. -- 2.34.1