Messages in this thread | | | Subject | Re: booting "nosmp" kernel causing ACPI errors | From | Zhang Rui <> | Date | Fri, 22 Oct 2010 08:29:56 +0800 |
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Hi, Bernard,
On Wed, 2010-10-20 at 05:45 +0800, Bernard Pidoux wrote: > 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. > do you want to run a up kernel or just want to enable one processor?
> 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 > that's correct, but note that you're still running a smp kernel in this case.
when using maxcpus=1, you're running a *_smp_* kernel, which detects one processor and stops. when using maxcpus=0, you're running a up kernel which surely doesn't have the ioapic support, and is not able to detect the other processors.
thanks, rui > 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 > > > > -- > 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/
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