Context Switching?
Posted: 6. Jun 2012, 15:13
Hello,
Today I found out that running a simple infinite loop in a VM is extremely slow compared with running same app natively.
When I looked at Activity Monitor, I saw the the main CPU usage has been switching between cores too many times(like once every second) in the VM.
When I run a simple while(1) natively on the machine, it tales a lot more time to change which core it runs(triples the time).
When I run HTOP on the guest machine, it thinks it is running all the way on the same core.
Is it something with Lion? Can I change it?
I really think my services are loosing performance because of this issue.
I was surprised, because I had all accelerations activated.
Accelerations:
VT-X/AMD-V
Nested Paging
PAE/NX
All 24 Cores
100% Cap
Other Info
Chipset: PIIX3
Mem Allocated for VM: 4GB
IO APIC
Running UBUNTU SERVER
uname -a on the guest gives:
Linux paleows 2.6.32-41-server #89-Ubuntu SMP x86_64
Today I found out that running a simple infinite loop in a VM is extremely slow compared with running same app natively.
When I looked at Activity Monitor, I saw the the main CPU usage has been switching between cores too many times(like once every second) in the VM.
When I run a simple while(1) natively on the machine, it tales a lot more time to change which core it runs(triples the time).
When I run HTOP on the guest machine, it thinks it is running all the way on the same core.
Is it something with Lion? Can I change it?
I really think my services are loosing performance because of this issue.
I was surprised, because I had all accelerations activated.
Accelerations:
VT-X/AMD-V
Nested Paging
PAE/NX
All 24 Cores
100% Cap
Other Info
Chipset: PIIX3
Mem Allocated for VM: 4GB
IO APIC
Running UBUNTU SERVER
uname -a on the guest gives:
Linux paleows 2.6.32-41-server #89-Ubuntu SMP x86_64