Re: Why do so many machines need "noapic"?

[Chuck Ebbert <cebbert@redhat.com>]

On 09/06/2007 07:31 AM, Andi Kleen wrote:
> Chuck Ebbert <cebbert@redhat.com> writes:
> 
>> Some systems lock up without the noapic option.
> 
> Please find patterns: cpu type, chipsets, mainboard vendors etc.
> 

This is the first one I've actually had in front of me:

  HP TX1000 notebook
  Nvidia C51/MCP51 mobile chipset

Booting with "noapic" gives some very strange results. This is two
snapshots of /proc/interrupts taken one second apart. It almost looks
like timer interrupts are occurring on IRQ 0 and IRQ7 on different
CPUs:

           CPU0       CPU1       
  0:     446096       6224    XT-PIC-XT        timer
  1:        342          6    XT-PIC-XT        i8042
  2:          0          0    XT-PIC-XT        cascade
  5:       3099        865    XT-PIC-XT        sata_nv
  7:       8145     494718    XT-PIC-XT        ehci_hcd:usb2
  8:          0          0    XT-PIC-XT        rtc0
  9:        323          9    XT-PIC-XT        acpi
 10:        136         36    XT-PIC-XT        HDA Intel
 11:      43884       1091    XT-PIC-XT        ohci_hcd:usb1, eth0
 12:        104         19    XT-PIC-XT        i8042
 14:       1011         25    XT-PIC-XT        libata
 15:          0          0    XT-PIC-XT        libata
NMI:          0          0 
LOC:       6212     445951 
ERR:     403241
MIS:          0

           CPU0       CPU1       
  0:     447098       6233    XT-PIC-XT        timer
  1:        343          6    XT-PIC-XT        i8042
  2:          0          0    XT-PIC-XT        cascade
  5:       3100        865    XT-PIC-XT        sata_nv
  7:       8158     495847    XT-PIC-XT        ehci_hcd:usb2
  8:          0          0    XT-PIC-XT        rtc0
  9:        323          9    XT-PIC-XT        acpi
 10:        136         36    XT-PIC-XT        HDA Intel
 11:      43988       1094    XT-PIC-XT        ohci_hcd:usb1, eth0
 12:        104         19    XT-PIC-XT        i8042
 14:       1032         26    XT-PIC-XT        libata
 15:          0          0    XT-PIC-XT        libata
NMI:          0          0 
LOC:       6221     446953 
ERR:     404383
MIS:          0


>> I found one
>> that will freeze while trying to set up the timer interrupt.
>> Passing 'nolapic' makes it freeze just after:
>>
>>    Setting up timer through ExtINT... works
> 
> Always boot with apic=debug
> 

I can't capture the messages. Even when it boots it doesn't last
long enough to get them.