Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752043Ab2J2Gq6 (ORCPT ); Mon, 29 Oct 2012 02:46:58 -0400 Received: from 1wt.eu ([62.212.114.60]:34634 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751113Ab2J2Gq4 (ORCPT ); Mon, 29 Oct 2012 02:46:56 -0400 Date: Mon, 29 Oct 2012 07:46:43 +0100 From: Willy Tarreau To: Mark Lord Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Linux Kernel , Jacob Shin , "H. Peter Anvin" Subject: Re: Regression from 3.4.9 to 3.4.16 "stable" kernel Message-ID: <20121029064643.GE574@1wt.eu> References: <508E002B.4090200@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <508E002B.4090200@teksavvy.com> User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2484 Lines: 68 On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote: > My server here runs the 3.4.xx series of "stable" kernels. > Until today, it was running 3.4.9. > Today I tried to upgrade it to 3.4.16. > It hangs in setup.c. > > I've isolated the fault down to this specific change > that was made between 3.4.9 and 3.4.16. > Reverting this change allows the system to boot/run normally again. > > > --- linux-3.4.9/arch/x86/kernel/setup.c 2012-08-15 11:17:17.000000000 -0400 > +++ linux-3.4.16/arch/x86/kernel/setup.c 2012-10-28 13:36:33.000000000 -0400 > @@ -927,8 +927,21 @@ > > #ifdef CONFIG_X86_64 > if (max_pfn > max_low_pfn) { > - max_pfn_mapped = init_memory_mapping(1UL<<32, > - max_pfn< + int i; > + for (i = 0; i < e820.nr_map; i++) { > + struct e820entry *ei = &e820.map[i]; > + > + if (ei->addr + ei->size <= 1UL << 32) > + continue; > + > + if (ei->type == E820_RESERVED) > + continue; > + > + max_pfn_mapped = init_memory_mapping( > + ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr, > + ei->addr + ei->size); > + } > + > /* can we preseve max_low_pfn ?*/ > max_low_pfn = max_pfn; > } For the record, it is this commit introduced in 3.4.16 : commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721 Author: Jacob Shin Date: Thu Oct 20 16:15:26 2011 -0500 x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping. commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream. On systems with very large memory (1 TB in our case), BIOS may report a reserved region or a hole in the E820 map, even above the 4 GB range. Exclude these from the direct mapping. [ hpa: this should be done not just for > 4 GB but for everything above the legacy region (1 MB), at the very least. That, however, turns out to require significant restructuring. That work is well underway, but is not suitable for rc/stable. ] Signed-off-by: Jacob Shin Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman Willy -- 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/