Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753028AbaJ1R3T (ORCPT ); Tue, 28 Oct 2014 13:29:19 -0400 Received: from www.linutronix.de ([62.245.132.108]:51388 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750979AbaJ1R3S (ORCPT ); Tue, 28 Oct 2014 13:29:18 -0400 Date: Tue, 28 Oct 2014 18:29:07 +0100 (CET) From: Thomas Gleixner To: "H. Peter Anvin" cc: Minfei Huang , mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: Avoid overlap the fixmap area on i386 In-Reply-To: <544FD138.3030305@zytor.com> Message-ID: References: <6B680A9E-6CE9-4C96-934B-CB01DCB58278@gmail.com> <544FD138.3030305@zytor.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Oct 2014, H. Peter Anvin wrote: > 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. Fair enough. Then we should do that for the highmem=y case as well. Thanks, tglx -- 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/