From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754307Ab3KLAQ5 (ORCPT ); Mon, 11 Nov 2013 19:16:57 -0500 Received: from mga09.intel.com ([134.134.136.24]:47195 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868Ab3KLAQt (ORCPT ); Mon, 11 Nov 2013 19:16:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="407152568" From: "H. Peter Anvin" To: Ingo Molnar , Linux Kernel Mailing List , Thomas Gleixner Cc: Olof Johansson , "H. Peter Anvin" Subject: [RFC PATCH 0/3] x86, boot: Low memory reservation fixes Date: Mon, 11 Nov 2013 16:16:44 -0800 Message-Id: <1384215407-22288-1-git-send-email-hpa@linux.intel.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" On all but the tiniest of modern systems, losing half a megabyte of RAM is a small price to pay for system stability. Thus, switch the default for low memory reservation to 640K. This has been possible, but has not been the default, since v3.9, specifically checkin: 95c9608478d6 x86, mm: Move reserving low memory later in initialization The above checkin exposes a problem with our reservation ordering; specifically setup_bios_corruption_check() is called too early, so fix that. This caused the BIOS corruption check to run on memory that would have been reserved anyway. Finally, change the low memory check scanner to scan 640K rather than 64K by default. The low memory check scanner will be a noop in the common case, as it now will only grab memory that is not otherwise reserved; this makes it purely a diagnostic tool. H. Peter Anvin (3): x86, boot: Move setup_bios_corruption_check() later x86, boot: Change the default for X86_RESERVE_LOW to 640K, make EXPERT x86, boot: Change the BIOS corruption checker to scan 640K