Re: strange guest slowness after some time

[Tomasz Chmielewski <mangoo@wpkg.org>]

Avi Kivity schrieb:
> Tomasz Chmielewski wrote:
>>>
>>> It was kvm-clock.
>>> I tried changing it to acpi_pm, jiffies, tsc, but it made no difference.
>>
>> Actually, I don't think that I checked tsc, because when I changed to 
>> jiffies, the time has stopped:
>>
>> # echo jiffies > 
>> /sys/devices/system/clocksource/clocksource0/current_clocksource
>> # date
>> Mon Mar  9 12:29:00 CET 2009
>> # date
>> Mon Mar  9 12:29:00 CET 2009
>> # date
>> Mon Mar  9 12:29:00 CET 2009
> 
> can you post some /proc/interrupt dumps from the guest?  I guess the 
> timer interrupt isn't working.

We're touching another issue from my original one ("guest slowness") 
here, I suppose.

But there are new interrupts here, when I set the clocksource to 
"jiffies" (setting to "jiffies" also kills my serial console connection 
- no key press go through to the guest any more):

# cat /proc/interrupts
            CPU0
   0:        104   IO-APIC-edge      timer
   1:          6   IO-APIC-edge      i8042
   4:        480   IO-APIC-edge      serial
   6:          2   IO-APIC-edge      floppy
   7:          0   IO-APIC-edge      parport0
   8:          2   IO-APIC-edge      rtc0
   9:          0   IO-APIC-fasteoi   acpi
  10:       4400   IO-APIC-fasteoi   virtio0, virtio2, virtio4
  11:       1550   IO-APIC-fasteoi   uhci_hcd:usb1, virtio1, virtio3
  12:         89   IO-APIC-edge      i8042
  14:          0   IO-APIC-edge      ide0
  15:         30   IO-APIC-edge      ide1
NMI:          0   Non-maskable interrupts
LOC:      85231   Local timer interrupts
RES:          0   Rescheduling interrupts
CAL:          0   function call interrupts
TLB:          0   TLB shootdowns
TRM:          0   Thermal event interrupts
SPU:          0   Spurious interrupts
ERR:          0
MIS:          0

# cat /proc/interrupts
            CPU0
   0:        104   IO-APIC-edge      timer
   1:          6   IO-APIC-edge      i8042
   4:        486   IO-APIC-edge      serial
   6:          2   IO-APIC-edge      floppy
   7:          0   IO-APIC-edge      parport0
   8:          2   IO-APIC-edge      rtc0
   9:          0   IO-APIC-fasteoi   acpi
  10:       4461   IO-APIC-fasteoi   virtio0, virtio2, virtio4
  11:       1590   IO-APIC-fasteoi   uhci_hcd:usb1, virtio1, virtio3
  12:         89   IO-APIC-edge      i8042
  14:          0   IO-APIC-edge      ide0
  15:         30   IO-APIC-edge      ide1
NMI:          0   Non-maskable interrupts
LOC:     108361   Local timer interrupts
RES:          0   Rescheduling interrupts
CAL:          0   function call interrupts
TLB:          0   TLB shootdowns
TRM:          0   Thermal event interrupts
SPU:          0   Spurious interrupts
ERR:          0
MIS:          0



> Does -no-kvm-irqchip help?

Nope, it doesn't - with jiffies, time always stops.


-- 
Tomasz Chmielewski
http://wpkg.org