From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757987Ab0JSVmj (ORCPT ); Tue, 19 Oct 2010 17:42:39 -0400 Received: from shiva144.upmc.fr ([134.157.0.144]:50113 "EHLO shiva.upmc.fr" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753247Ab0JSVmi (ORCPT ); Tue, 19 Oct 2010 17:42:38 -0400 X-Ids: courriel2 Message-ID: <4CBE1179.2040003@upmc.fr> Date: Tue, 19 Oct 2010 23:45:29 +0200 From: Bernard Pidoux User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100919 Mandriva/3.0.8-0.1mdv2010.1 (2010.1) Thunderbird/3.0.8 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Bernard Pidoux Subject: Re: booting "nosmp" kernel causing ACPI errors References: <4CB9D69D.60203@upmc.fr> In-Reply-To: <4CB9D69D.60203@upmc.fr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I needed to run Linux on UP mode in order to perform some application tests. Using nosmp argument lead to bad interrupts set up. I finally found the explanation I was looking for in this acpi-linux thread : http://marc.info/?l=linux-acpi&m=118794015205199&w=4 maxcpus= [SMP] Maximum number of processors that an SMP kernel should make use of. maxcpus=n : n>= 0 limits the kernel to using 'n' processors. n=0 is a special case, it is equivalent to "nosmp", which also disables the IO APIC. nosmp [SMP] Tells an SMP kernel to act as a UP kernel, and disable the IO APIC. legacy for "maxcpus=0". I understand that the reason why nosmp also disable IO APIC is for backward compatibility. However this is not intuitive : one argument leading to two actions. So, if I want to run my dual core CPU in UniProcessor mode I have to use kernel argument maxcpus=1 in grub/menu.lst Doing so, interrupts on my Linux system are correctly initialized and it is much more stable. Bernard Le 16/10/2010 18:45, Bernard Pidoux a écrit : > Hi, > > I observed ACPI errors when booting 2.6.35.7 kernel with "nosmp" > argument. > dmesg shows a warning message starting with : > WARNING: at mm/page_alloc.c:1981 __alloc_pages_nodemask+0x5b4/0x6d0() > +Hardware name: MS-7519 > +Modules linked in: > +Pid: 1, comm: swapper Not tainted 2.6.35.7 #2 > > This is followed by ACPI error messages and /proc/interrupts show that > interrupts 0-15 are then handled by XT-PIC-XT > instead of IO-APIC-edge and IO-APIC-fasteoi when runing smp kernel. > > Here is lspci dump : > > 00:00.0 Host bridge: Intel Corporation 4 Series Chipset DRAM > Controller (rev 03) > 00:01.0 PCI bridge: Intel Corporation 4 Series Chipset PCI Express > Root Port (rev 03) > 00:1a.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #4 > 00:1a.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #5 > 00:1a.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #6 > 00:1a.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 > EHCI Controller #2 > 00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD > Audio Controller > 00:1c.0 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI > Express Root Port 1 > 00:1c.1 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI > Express Port 2 > 00:1c.5 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI > Express Root Port 6 > 00:1d.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #1 > 00:1d.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #2 > 00:1d.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB > UHCI Controller #3 > 00:1d.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 > EHCI Controller #1 > 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90) > 00:1f.0 ISA bridge: Intel Corporation 82801JIB (ICH10) LPC Interface > Controller > 00:1f.2 IDE interface: Intel Corporation 82801JI (ICH10 Family) 4 port > SATA IDE Controller #1 > 00:1f.3 SMBus: Intel Corporation 82801JI (ICH10 Family) SMBus Controller > 00:1f.5 IDE interface: Intel Corporation 82801JI (ICH10 Family) 2 port > SATA IDE Controller #2 > 01:00.0 VGA compatible controller: nVidia Corporation G98 [GeForce > 8400 GS] (rev a1) > 02:00.0 IDE interface: JMicron Technology Corp. JMB368 IDE controller > 04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. > RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02) > > I observed the same issue with another machine with also an MSI > motherboard but using a PCI bridge VIA VT8237/VX700 > even when booting with "pci=use_crs" argument. > > Attached is diff -ruN file between 2.6.35.7 kernel without and with > "nosmp" boot argument. > > Bernard >