From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755427Ab3KUXTj (ORCPT ); Thu, 21 Nov 2013 18:19:39 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58731 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752381Ab3KUXTg (ORCPT ); Thu, 21 Nov 2013 18:19:36 -0500 Message-ID: <528E94D1.2050809@zytor.com> Date: Thu, 21 Nov 2013 15:18:41 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Matthew Garrett , Jerry Hoemann CC: rob@landley.net, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, matt.fleming@intel.com, yinghai@kernel.org, akpm@linux-foundation.org, bp@suse.de, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, penberg@kernel.org, mingo.kernel.org@gmail.com, vgoyal@redhat.com Subject: Re: [RFC v2 0/2] Early use of boot service memory References: <1385067686-73500-1-git-send-email-jerry.hoemann@hp.com> <20131121230744.GA31592@srcf.ucam.org> In-Reply-To: <20131121230744.GA31592@srcf.ucam.org> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/21/2013 03:07 PM, Matthew Garrett wrote: > On Thu, Nov 21, 2013 at 02:01:24PM -0700, Jerry Hoemann wrote: >> >> Some platform have firmware that violates the UEFI spec and access boot >> service code or data segments after the system has called ExitBootServices(). >> The call to efi_reserve_boot_services in setup_arch is a workaround to >> avoid using boot service memory until after the kernel has done >> SetVirtualAddressMap. However, this reservation fragments memory >> which can cause large allocations early in boot (e.g. crash kernel) >> to fail. > > This is a problem we have to solve, but I don't think this is the right > way to solve it. Why do we not just reattempt to perform the allocation > immediately after we've freed the boot services regions? > Wouldn't the memory map already have gotten scrambled all to hell by then? -hpa