Re: Yet another question about CPU Scheduling

Hi Andy!

Thank you very much for your answer! It makes complete sense but some documentation talk about things like "if xxxMhz are available" which makes me think that maybe the kernel IS able to accomodate more than one world at the same time and to "split" the processor's Mhz.

http://frankdenneman.nl/2010/06/08/reservations-and-cpu-scheduling/

http://www.yellow-bricks.com/2010/05/18/limiting-your-vcpu/

http://pubs.vmware.com/vsphere-51/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-51-resource-management-guide.pdf

Then things like the one you mention or this paragraph from the document i linked, makes me doubt...it could be ambiguous as it leaves the door open for vCPUs of different VMs running on the same pCPU.

"To ensure that sibling vCPUs of a multiprocessor virtual machine are co-scheduled as much as possible, the CPU

Or other things like this one found in the resource management guide (page 12)

"For example, assume you have 2GHz available and specify a reservation of 1GHz for VM1 and 1GHz for VM2.

Now each virtual machine is guaranteed to get 1GHz if it needs it. However, if VM1 is using only 500MHz,

VM2 can use 1.5GHz."

I feel really dumb knowing that the information is out there but I just can't fully understand it I read those papers over and over but I just can't get to any conclusion.

Thanks again for your help!!!

elgreco81