Re: [PATCH] i386: disable local apic timer via command line or dmi quirk

From: Len Brown
Date: Tue Mar 27 2007 - 23:46:35 EST


On Tuesday 27 March 2007 23:28, Len Brown wrote:
> Thomas,
>
> Is this failure specific to NO_HZ, and that is why the "nolapic_timer" fix is i386 only?
> I'm running 2.6.21-rc5 an nx6325 here in 64-bit mode and I don't see the dramatic
> boot failure described earlier in this thread.
>
> However, I have observed that when running on battery,
> the LOC falls behind the irq0 timer to the tune of about
> 2 interrupt/minute. eg. when i booted my machine, LOC was
> behind irq0 by 50, and now about a 20 minutes later it is behind
> irq0 by 99. However, the LOC for each processor remain at
> a constant offset with respect to each other.
>
> I do not see these this drift when running on AC.

Correction.
I double-checked and the same drift is present between irq0
and LOC when on AC:

lenb@nx6325:/tmp/sut> uname -a; cat /proc/interrupts; sleep 100; cat /proc/interrupts
Linux nx6325 2.6.21-rc5 #37 SMP Tue Mar 27 22:26:00 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux
CPU0 CPU1
0: 1000442 0 <NULL>-edge timer
1: 724 0 IO-APIC-edge i8042
8: 0 0 IO-APIC-edge rtc
12: 36299 0 IO-APIC-edge i8042
14: 33661 0 IO-APIC-edge ide0
16: 20676 0 IO-APIC-fasteoi libata
19: 21 0 IO-APIC-fasteoi ehci_hcd:usb1, ohci_hcd:usb2, ohci_hcd:usb3
20: 1 0 IO-APIC-fasteoi ohci1394
21: 9388 0 IO-APIC-fasteoi acpi
23: 43794 0 IO-APIC-fasteoi eth0
NMI: 0 0
LOC: 1000271 1000247
ERR: 0
CPU0 CPU1
0: 1025442 0 <NULL>-edge timer
1: 724 0 IO-APIC-edge i8042
8: 0 0 IO-APIC-edge rtc
12: 39539 0 IO-APIC-edge i8042
14: 34506 0 IO-APIC-edge ide0
16: 22172 0 IO-APIC-fasteoi libata
19: 21 0 IO-APIC-fasteoi ehci_hcd:usb1, ohci_hcd:usb2, ohci_hcd:usb3
20: 1 0 IO-APIC-fasteoi ohci1394
21: 9630 0 IO-APIC-fasteoi acpi
23: 44826 0 IO-APIC-fasteoi eth0
NMI: 0 0
LOC: 1025269 1025245
ERR: 0
lenb@nx6325:/tmp/sut> bc -l
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
1025442-1000442
25000
1025269-1000271
24998
lenb@nx6325:/tmp/sut> cat /proc/acpi/ac_adapter/C1BD/state
state: on-line

-Len

> Yes, the system exports just C1 in both cases.
>
> Other oddities is the IRQ name on irq0 is garbled:
>
> lenb@nx6325:~> uname -a; cat /proc/interrupts; sleep 100; cat /proc/interrupts
> Linux nx6325 2.6.21-rc5 #37 SMP Tue Mar 27 22:26:00 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux
> CPU0 CPU1
> 0: 723812 0 <NULL>-edge timer
> 1: 716 0 IO-APIC-edge i8042
> 8: 0 0 IO-APIC-edge rtc
> 12: 30719 0 IO-APIC-edge i8042
> 14: 24318 0 IO-APIC-edge ide0
> 16: 18316 0 IO-APIC-fasteoi libata
> 19: 21 0 IO-APIC-fasteoi ehci_hcd:usb1, ohci_hcd:usb2, ohci_hcd:usb3
> 20: 1 0 IO-APIC-fasteoi ohci1394
> 21: 6736 0 IO-APIC-fasteoi acpi
> 23: 30358 0 IO-APIC-fasteoi eth0
> NMI: 0 0
> LOC: 723675 723651
> ERR: 0
> CPU0 CPU1
> 0: 748812 0 <NULL>-edge timer
> 1: 716 0 IO-APIC-edge i8042
> 8: 0 0 IO-APIC-edge rtc
> 12: 30719 0 IO-APIC-edge i8042
> 14: 25164 0 IO-APIC-edge ide0
> 16: 18361 0 IO-APIC-fasteoi libata
> 19: 21 0 IO-APIC-fasteoi ehci_hcd:usb1, ohci_hcd:usb2, ohci_hcd:usb3
> 20: 1 0 IO-APIC-fasteoi ohci1394
> 21: 6960 0 IO-APIC-fasteoi acpi
> 23: 31385 0 IO-APIC-fasteoi eth0
> NMI: 0 0
> LOC: 748673 748649
> ERR: 0
> lenb@nx6325:~> bc -l
> bc 1.06
> Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
> This is free software with ABSOLUTELY NO WARRANTY.
> For details type `warranty'.
> 748812-723812
> 25000
> 748673-723675
> 24998
> 723812-723675
> 137
> 748812-748673
> 139
> lenb@nx6325:~>
>
> Further, in dmesg:
> ATI board detected. Disabling timer routing over 8254.
>
> ..MP-BIOS bug: 8254 timer not connected to IO-APIC
>
> -Len
>
>
>
-
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