Re: Unbalanced timer interrupts under VMWare?

2011-12-21 Thread Ivan Voras

On 21.12.2011. 14:48, Maxim Dounin wrote:

Hello!

On Wed, Dec 21, 2011 at 12:02:04PM +0100, Ivan Voras wrote:



Unless the tickless kernel project has advanced more than I think,


It is, actually.  Many thanks to mav@ for his amazing work.

$ sysctl kern.eventtimer.periodic
kern.eventtimer.periodic: 0

$ vmstat -i | grep timer
cpu0:timer  72769640 47


Ah, great! I missed that commit :) Thanks mav!


And down to 37 i/s as seen in "systat -vm".  Idle virtual machine
now takes 2 times less CPU on my laptop as seen from the host.


this looks like a problem... so I looked elsewhere and it turns out
I cannot get more than about 55 interrupts/s with the disk
controller either.


Happily goes to 6k i/s here (though it's under VirtualBox and
a bit old -current, not 9.0).


Yes, it looks like it's not related to the tickless mode, the disk IO is 
slow even when kern.eventtimer.periodic=1. Something else is broken.



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Re: Unbalanced timer interrupts under VMWare?

2011-12-21 Thread Maxim Dounin
Hello!

On Wed, Dec 21, 2011 at 12:02:04PM +0100, Ivan Voras wrote:

> I have a strange situation on a VMWare 5-hosted machine:
> 
> # vmstat -i
> interrupt  total   rate
> irq1: atkbd0  74  0
> irq6: fdc011  0
> irq15: ata1   17  0
> irq18: em0 42122  1
> cpu0:timer   2246291 54
> irq256: mpt0  141402  3
> cpu1:timer280800  6
> Total2710717 65
> 
> The cpu0 timer interrupt rate is 54 Hz and cpu1 rate is 6 Hz. The
> same is visible when monitoring the system in real time with "systat
> -vm".
> 
> This is a default FreeBSD 9 RC3 amd64 system, HZ is the default 100.
> Unless the tickless kernel project has advanced more than I think,

It is, actually.  Many thanks to mav@ for his amazing work.

$ sysctl kern.eventtimer.periodic
kern.eventtimer.periodic: 0

$ vmstat -i | grep timer
cpu0:timer  72769640 47

And down to 37 i/s as seen in "systat -vm".  Idle virtual machine 
now takes 2 times less CPU on my laptop as seen from the host. 

> this looks like a problem... so I looked elsewhere and it turns out
> I cannot get more than about 55 interrupts/s with the disk
> controller either.

Happily goes to 6k i/s here (though it's under VirtualBox and 
a bit old -current, not 9.0).

(Just in case: note that vmstat report rate since boot, "systat -vm"
may be better to look at current values.)

> Any ideas? I have another host running VMware 5 but only an 8-stable
> machine in it, which works fine. Does anyone else run 9.x on VMware
> 5?
> 
> The host is a Xeon X3360 CPU (4 cores, no HTT, 2.8 GHz).

Maxim Dounin
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Unbalanced timer interrupts under VMWare?

2011-12-21 Thread Ivan Voras

I have a strange situation on a VMWare 5-hosted machine:

# vmstat -i
interrupt  total   rate
irq1: atkbd0  74  0
irq6: fdc011  0
irq15: ata1   17  0
irq18: em0 42122  1
cpu0:timer   2246291 54
irq256: mpt0  141402  3
cpu1:timer280800  6
Total2710717 65

The cpu0 timer interrupt rate is 54 Hz and cpu1 rate is 6 Hz. The same 
is visible when monitoring the system in real time with "systat -vm".


This is a default FreeBSD 9 RC3 amd64 system, HZ is the default 100. 
Unless the tickless kernel project has advanced more than I think, this 
looks like a problem... so I looked elsewhere and it turns out I cannot 
get more than about 55 interrupts/s with the disk controller either.


Any ideas? I have another host running VMware 5 but only an 8-stable 
machine in it, which works fine. Does anyone else run 9.x on VMware 5?


The host is a Xeon X3360 CPU (4 cores, no HTT, 2.8 GHz).

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