Bug 702202

Description of problem:

We are running kvm as vmm and upgrating our guest from RHEL5.5 to RHEL6.0
but we observer higher system utilization with same pressure/workloads.

One thing we notice is we have divider=10 in RHEL5.5 so the timer interrupt is less than what we got on RHEL6. 
to verify this, we use `cat /proc/interrupts |grep LOC; sleep 10; cat /proc/interrupts |grep LOC` to collect the interrupts inside 10s.
we found that the RHEL5 vm with divider=10. There is 100/s exactly for one cpu.
while with RHEL6 vm, it's ~883/s for one cpu.

we know the divider=10 will help for decrease system utilization. 
(exp: http://www.arrfab.net/blog/?p=62)

so I'm wondering if this is a expected? any similar tunnings for RHEL6 to lower the timmer interrupt as divider=10?


Version-Release number of selected component (if applicable):
6.0

How reproducible:
every time

Steps to Reproduce:
1. Setup two Guest VMM on KVM with RHEL6, one is RHEL5.5 one is RHEL6. add divider=10 for RHEL5.5
2. run some same workload for 2 VMM. (we use internal ones with constant pressure too complicate to setup and I think a simpler workload with ~50% load will be OK)
3. use `cat /proc/interrupts |grep LOC; sleep 10; cat /proc/interrupts |grep LOC` to collect the interrupts between two VMM.
  
Actual results:
Higher timmer interrupts/System utilization for RHEL6 then RHEL5.5+divider=10


Expected results:
Less or at leaset similar.

Additional info: