From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754531Ab0ASWCv (ORCPT ); Tue, 19 Jan 2010 17:02:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754162Ab0ASWCu (ORCPT ); Tue, 19 Jan 2010 17:02:50 -0500 Received: from mail-fx0-f215.google.com ([209.85.220.215]:46878 "EHLO mail-fx0-f215.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751947Ab0ASWCu (ORCPT ); Tue, 19 Jan 2010 17:02:50 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=X7DIkrG5fy0q5vNX8pKoIqb3RN1V0ULO5vsva0xvU2fOM+HoiaY+uAo8lUWn0FmJW+ ZzxC9OTcGqOr/jRvJCIO12bXuI/DWW7FfON1MxnepYHPiVqhoorCNFg7XeTZRoJIsjb8 PJc5Wlq0lvZ923APSti4BOzDNgRMF2nD/1G0o= Message-ID: <4B562C05.6080404@gmail.com> Date: Tue, 19 Jan 2010 23:02:45 +0100 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; cs-CZ; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-17.1 Thunderbird/3.0 MIME-Version: 1.0 To: Johannes Weiner CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ralf Baechle , x86@kernel.org Subject: Re: [RFC 1/1] bootmem: move big allocations behing 4G References: <1263855390-32497-1-git-send-email-jslaby@suse.cz> <20100119143355.GB7932@cmpxchg.org> In-Reply-To: <20100119143355.GB7932@cmpxchg.org> X-Enigmail-Version: 1.0 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 01/19/2010 03:33 PM, Johannes Weiner wrote: > On Mon, Jan 18, 2010 at 11:56:30PM +0100, Jiri Slaby wrote: >> Hi, I'm fighting a bug where Grub loads the kernel just fine, whereas >> isolinux doesn't. I found out, it's due to different addresses of >> loaded initrd. On a machine with 128G of memory, grub loads the >> initrd at 895M in our case and flat mem_map (2G long) is allocated >> above 4G due to 2-4G BIOS reservation. >> >> On the other hand, with isolinux, the 0-2G is free and mem_map is >> placed there leaving no space for others, hence kernel panics for >> swiotlb which needs to be below 4G. > > Bootmem already protects the lower 16MB DMA zone for the obvious reasons, > how about shifting the default bootmem goal above the DMA32 zone if it exists? Hi, I think it makes sense. > I tested the below on a rather dull x86_64 machine and it seems to work. Would > this work in your case as well? The goal for mem_map should now be above 4G. It seems that it will. I'll give it a try later (it needs to be set up) and report back. > From 1c11ce1e82c6209f0eda72e3340ab0c55cd6f330 Mon Sep 17 00:00:00 2001 > From: Johannes Weiner > Date: Tue, 19 Jan 2010 14:14:44 +0100 > Subject: [patch] bootmem: avoid DMA32 zone, if any, by default > > x86_64 and mips define a DMA32 zone additionally to the old DMA > zone of 16MB. Bootmem already avoids the old DMA zone if the > allocation site did not request otherwise. > > But since DMA32 is also a limited resource, avoid using it as well > by default, if defined. > > Signed-off-by: Johannes Weiner So for the time being: Reviewed-by: Jiri Slaby thanks, -- js