Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754881AbZF2L5c (ORCPT ); Mon, 29 Jun 2009 07:57:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751611AbZF2L5X (ORCPT ); Mon, 29 Jun 2009 07:57:23 -0400 Received: from aun.it.uu.se ([130.238.12.36]:58998 "EHLO aun.it.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751486AbZF2L5W (ORCPT ); Mon, 29 Jun 2009 07:57:22 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <19016.44061.600652.676183@pilspetsen.it.uu.se> Date: Mon, 29 Jun 2009 13:57:17 +0200 From: Mikael Pettersson To: Matthew Wilcox Cc: Mikael Pettersson , "H. Peter Anvin" , Grant Grundler , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [BUG 2.6.31-rc1] HIGHMEM64G causes hang in PCI init on 32-bit x86 In-Reply-To: <20090629112155.GJ5480@parisc-linux.org> References: <200906261559.n5QFxJH8027336@pilspetsen.it.uu.se> <19013.29264.623540.275538@pilspetsen.it.uu.se> <4A45A5C1.5080701@zytor.com> <19013.59956.144640.331854@pilspetsen.it.uu.se> <20090629022911.GC20297@lackof.org> <4A484A8A.9020704@zytor.com> <19016.41349.636663.515540@pilspetsen.it.uu.se> <20090629112155.GJ5480@parisc-linux.org> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4137 Lines: 104 Matthew Wilcox writes: > On Mon, Jun 29, 2009 at 01:12:05PM +0200, Mikael Pettersson wrote: > > H. Peter Anvin writes: > > > Grant Grundler wrote: > > > > On Sat, Jun 27, 2009 at 11:45:24AM +0200, Mikael Pettersson wrote: > > > > ... > > > >> fff00000-fffffffe : pnp 00:09 > > > >> 100000000-1ffffffff : System RAM > > > >> 200000000-ffffffffffffffff : RAM buffer > > > >> > > > >> With 2.6.30 things look similar, except 2.6.30 does not show the > > > >> last "200000000-ffffffffffffffff : RAM buffer" line. > > > > > > > > BIOS e280 table didn't report that line. > > > > I expect it's created by arch/x86/kernel/e820.c: > > > > 1398 /* > > > > 1399 * Try to bump up RAM regions to reasonable boundaries to > > > > 1400 * avoid stolen RAM: > > > > 1401 */ > > > > 1402 for (i = 0; i < e820.nr_map; i++) { > > > > 1403 struct e820entry *entry = &e820_saved.map[i]; > > > > 1404 resource_size_t start, end; > > > > 1405 > > > > 1406 if (entry->type != E820_RAM) > > > > 1407 continue; > > > > 1408 start = entry->addr + entry->size; > > > > 1409 end = round_up(start, ram_alignment(start)); > > > > 1410 if (start == end) > > > > 1411 continue; > > > > 1412 reserve_region_with_split(&iomem_resource, start, > > > > 1413 end - 1, "RAM buffer"); > > > > 1414 } > > > > > > > > > > OK, this seems more than a wee bit strange, to say the least. We > > > shouldn't be reserving the entire address space; this is legitimate I/O > > > space. > > > > > > However, the reservation suddenly being improper for the root resource > > > would definitely make things unhappy... > > > > Reverting the two e820 changes in 2.6.31-rc1, > > 5d423ccd7ba4285f1084e91b26805e1d0ae978ed and then > > 45fbe3ee01b8e463b28c2751b5dcc0cbdc142d90, > > but keeping the iomem_resource.end cap change, makes 2.6.31-rc1 > > work on my HIGHMEM64G machine. > > > > Seems the e820 and the iomem_resource.end changes are Ok in > > isolation but break when combined. > > With the e820 change reverted, what does /proc/iomem look like? 00000000-0009ebff : System RAM 0009ec00-0009ffff : reserved 000a0000-000bffff : Video RAM area 000c0000-000ccfff : Video ROM 000e4000-000fffff : reserved 000f0000-000fffff : System ROM 00100000-7ff8ffff : System RAM 00100000-002e022e : Kernel code 002e022f-0038aaf7 : Kernel data 003d8000-003fc9f3 : Kernel bss 7ff90000-7ff9dfff : ACPI Tables 7ff9e000-7ffdffff : ACPI Non-volatile Storage 7ffe0000-7fffffff : reserved 88000000-880000ff : 0000:00:1f.3 bff00000-dfefffff : PCI Bus 0000:01 c0000000-cfffffff : 0000:01:00.0 e0000000-efffffff : PCI MMCONFIG 0 [00-ff] e0000000-efffffff : pnp 00:0e febfe000-febfec00 : pnp 00:09 fec00000-fec00fff : IOAPIC 0 fec00000-fec00fff : pnp 00:0b fed00000-fed003ff : HPET 0 fed14000-fed19fff : pnp 00:01 fed1c000-fed1ffff : pnp 00:09 fed20000-fed8ffff : pnp 00:09 fee00000-fee00fff : Local APIC fee00000-fee00fff : reserved fee00000-fee00fff : pnp 00:0b ff800000-ff8fffff : PCI Bus 0000:01 ff8c0000-ff8dffff : 0000:01:00.0 ff8e0000-ff8effff : 0000:01:00.1 ff8f0000-ff8fffff : 0000:01:00.0 ff900000-ff9fffff : PCI Bus 0000:02 ff9ffc00-ff9ffcff : 0000:02:02.0 ff9ffc00-ff9ffcff : 8139too ffaf8000-ffafbfff : 0000:00:1b.0 ffaf8000-ffafbfff : ICH HD audio ffaff000-ffaff3ff : 0000:00:1d.7 ffaff000-ffaff3ff : ehci_hcd ffaff400-ffaff7ff : 0000:00:1a.7 ffaff400-ffaff7ff : ehci_hcd ffaff800-ffafffff : 0000:00:1f.2 ffaff800-ffafffff : ahci ffb00000-ffffffff : reserved ffb00000-ffbfffff : pnp 00:09 fff00000-fffffffe : pnp 00:09 100000000-1ffffffff : System RAM -- 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/