Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757609AbZKKQUS (ORCPT ); Wed, 11 Nov 2009 11:20:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757588AbZKKQUR (ORCPT ); Wed, 11 Nov 2009 11:20:17 -0500 Received: from fg-out-1718.google.com ([72.14.220.156]:6245 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757600AbZKKQUP (ORCPT ); Wed, 11 Nov 2009 11:20:15 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=l+XKfr8ibvpJLiCmdvzaDBeWq3AuLTh3MllAqGirOxsg4E6wUlG0qqil/AelyEP2oA vLO4vkzRR5hY4VVqSns42ycIXSKqEgJPjCq0xcB9VZo30Sgw/ze/yaRYFWD15Z62AGpE wemSIjbjk/hrkevA8ikFpk2A3QteK9X4Y4zYg= Date: Thu, 12 Nov 2009 00:20:52 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: "Anton D. Kachalov" Cc: linux-kernel@vger.kernel.org Subject: Re: Reading /dev/mem by dd Message-ID: <20091111162052.GD2448@hack> References: <4AFACC03.7080209@mayc.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AFACC03.7080209@mayc.ru> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6338 Lines: 179 On Wed, Nov 11, 2009 at 05:36:51PM +0300, Anton D. Kachalov wrote: > Hello everyone! > > I've found strange behavior of reading /dev/mem: > > for i in 0 1 2; do > echo $i > dd if=/dev/mem of=/dev/null skip=$((6+$i)) bs=$((0x20000000)) count=1 > done > > On some systems with Supermicro X8DTU I've got several messages during > first 512Mb starting from 0xc000_0000: > > "BUG: soft lockup - CPU#xx stuck for 61s!" > > On other systems with the sameboard I've stuck without any errors at > last 10Mb before 0x1_0000_0000. Local APIC access? What is the full backtrace? And which version of kernel are you running? > > On E5440 (Dell PowerEdge 1950) I've just got several: > APIC error on CPU3: 00(80) > APIC error on CPU3: 80(80) > ... > APIC error on CPU3: 80(80) > That looks like wrong register access. > > [E5530] $ cat /proc/iomem > 00000000-0000ffff : reserved > 00010000-0009dbff : System RAM > 0009dc00-0009ffff : reserved > 000c0000-000cffff : pnp 00:0e > 000e0000-000fffff : reserved > 00100000-bf77ffff : System RAM > 00200000-006a37de : Kernel code > 006a37df-0091a57f : Kernel data > 00a68000-00b7cbaf : Kernel bss > bf78e000-bf78ffff : reserved > bf790000-bf79dfff : ACPI Tables > bf79e000-bf7cffff : ACPI Non-volatile Storage > bf7d0000-bf7dffff : reserved > bf7ec000-bfffffff : reserved > e0000000-efffffff : PCI MMCONFIG 0 > e0000000-efffffff : reserved > e0000000-efffffff : pnp 00:0d > f9000000-f9ffffff : PCI Bus 0000:07 > f9000000-f9ffffff : 0000:07:01.0 > faeda000-faeda0ff : 0000:00:1f.3 > faedc000-faedc3ff : 0000:00:1d.7 > faedc000-faedc3ff : ehci_hcd > faede000-faede3ff : 0000:00:1a.7 > faede000-faede3ff : ehci_hcd > faee0000-faee3fff : 0000:00:16.7 > faee4000-faee7fff : 0000:00:16.6 > faee8000-faeebfff : 0000:00:16.5 > faeec000-faeeffff : 0000:00:16.4 > faef0000-faef3fff : 0000:00:16.3 > faef4000-faef7fff : 0000:00:16.2 > faef8000-faefbfff : 0000:00:16.1 > faefc000-faefffff : 0000:00:16.0 > faf00000-faffffff : PCI Bus 0000:01 > faf00000-faf1ffff : 0000:01:00.1 > faf3c000-faf3ffff : 0000:01:00.1 > faf3c000-faf3ffff : igb > faf40000-faf5ffff : 0000:01:00.1 > faf40000-faf5ffff : igb > faf60000-faf7ffff : 0000:01:00.1 > faf60000-faf7ffff : igb > faf80000-faf9ffff : 0000:01:00.0 > fafbc000-fafbffff : 0000:01:00.0 > fafbc000-fafbffff : igb > fafc0000-fafdffff : 0000:01:00.0 > fafc0000-fafdffff : igb > fafe0000-faffffff : 0000:01:00.0 > fafe0000-faffffff : igb > fb000000-fbefffff : PCI Bus 0000:07 > fb000000-fb7fffff : 0000:07:01.0 > fbefc000-fbefffff : 0000:07:01.0 > fec00000-fec00fff : IOAPIC 0 > fec00000-fec00fff : pnp 00:0c > fed00000-fed003ff : HPET 0 > fed1c000-fed1ffff : pnp 00:01 > fed1c000-fed1ffff : pnp 00:0a > fed20000-fed3ffff : pnp 00:0a > fed40000-fed8ffff : pnp 00:0a > fee00000-fee00fff : Local APIC > fee00000-fee00fff : reserved > fee00000-fee00fff : pnp 00:0c > ffc00000-ffffffff : reserved > 100000000-13fffffff : System RAM > > [ 0.000000] BIOS-provided physical RAM map: > [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009dc00 (usable) > [ 0.000000] BIOS-e820: 000000000009dc00 - 00000000000a0000 (reserved) > [ 0.000000] BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) > [ 0.000000] BIOS-e820: 0000000000100000 - 00000000bf780000 (usable) > [ 0.000000] BIOS-e820: 00000000bf78e000 - 00000000bf790000 type 9 > [ 0.000000] BIOS-e820: 00000000bf790000 - 00000000bf79e000 (ACPI data) > [ 0.000000] BIOS-e820: 00000000bf79e000 - 00000000bf7d0000 (ACPI NVS) > [ 0.000000] BIOS-e820: 00000000bf7d0000 - 00000000bf7e0000 (reserved) > [ 0.000000] BIOS-e820: 00000000bf7ec000 - 00000000c0000000 (reserved) > [ 0.000000] BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) > [ 0.000000] BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved) > [ 0.000000] BIOS-e820: 00000000ffc00000 - 0000000100000000 (reserved) > [ 0.000000] BIOS-e820: 0000000100000000 - 0000000140000000 (usable) > > [E5440] $ cat /proc/iomem > 00000000-0009ffff : System RAM > 00000000-00000000 : Crash kernel > 000a0000-000bffff : Video RAM area > 000c0000-000c7fff : Video ROM > 000c9000-000c9fff : Adapter ROM > 000ca000-000cfbff : Adapter ROM > 000d0000-000d1dff : Adapter ROM > 000d2000-000d71ff : Adapter ROM > 000f0000-000fffff : System ROM > 00100000-bfb4ffff : System RAM > 00200000-003e1fbc : Kernel code > 003e1fbd-004bafe7 : Kernel data > bfb50000-bfb65fff : reserved > bfb66000-bfb85bff : ACPI Tables > bfb85c00-bfffffff : reserved > d0000000-d7ffffff : PCI Bus #10 > d0000000-d7ffffff : 0000:10:0d.0 > d8000000-d80fffff : PCI Bus #0c > d8000000-d80fffff : PCI Bus #0d > d80f0000-d80fffff : 0000:0d:0e.0 > d80f0000-d80fffff : megasas: LSI Logic > e0000000-efffffff : reserved > f2000000-f7ffffff : PCI Bus #04 > f4000000-f7ffffff : PCI Bus #05 > f4000000-f7ffffff : PCI Bus #06 > f4000000-f7ffffff : PCI Bus #07 > f4000000-f5ffffff : 0000:07:00.0 > f4000000-f5ffffff : bnx2 > f8000000-fbffffff : PCI Bus #02 > f8000000-fbffffff : PCI Bus #03 > f8000000-f9ffffff : 0000:03:00.0 > f8000000-f9ffffff : bnx2 > fc100000-fc2fffff : PCI Bus #10 > fc100000-fc11ffff : 0000:10:0d.0 > fc2d0000-fc2dffff : 0000:10:0d.0 > fc300000-fc5fffff : PCI Bus #0c > fc400000-fc5fffff : PCI Bus #0d > fc400000-fc407fff : 0000:0d:0e.0 > fc5c0000-fc5dffff : 0000:0d:0e.0 > fc5c0000-fc5dffff : megasas: LSI Logic > fc600000-fc8fffff : PCI Bus #01 > fc7e0000-fc7effff : 0000:01:00.0 > fc7fc000-fc7fffff : 0000:01:00.0 > fc800000-fc8fffff : 0000:01:00.0 > fc900000-fc9003ff : 0000:00:1d.7 > fc900000-fc9003ff : ehci_hcd > fe000000-ffffffff : reserved > 100000000-43fffffff : System RAM > > HP - ProLiant DL160G6 says: > http://www.pixsup.com/uploads/7134cd3e33.png > > Rgds, > Anton > -- > 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/ -- Live like a child, think like the god. -- 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/