Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751858AbaJ1RYY (ORCPT ); Tue, 28 Oct 2014 13:24:24 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53589 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407AbaJ1RYX (ORCPT ); Tue, 28 Oct 2014 13:24:23 -0400 Message-ID: <544FD138.3030305@zytor.com> Date: Tue, 28 Oct 2014 10:24:08 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Thomas Gleixner , Minfei Huang CC: mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: Avoid overlap the fixmap area on i386 References: <6B680A9E-6CE9-4C96-934B-CB01DCB58278@gmail.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/28/2014 04:06 AM, Thomas Gleixner wrote: >> >> The available address we can use is lower than FIXADDR_BOOT_START. So >> We will set the kmap boundary below the FIXADDR_BOOT_START, if configure >> the high memory. >> >> If we configure the high memory, the vmalloc reserve area should end >> up to PKMAP_BASE, otherwise should end up to FIXADDR_BOOT_START. > > Which is not really a problem, because the FIXADDR_BOOT area is only > used during boot for early_ioremap() and it's unused when ioremap() is > functional. vmalloc becomes available after early boot so the > FIXADDR_BOOT area is available for reuse. > Given the very limited address space available on i386, it would be extremely undesirable to not reuse address space when possible. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/