Nested/Extended Page Table (EPT) is the current hardware solution for virtualizing memory in virtualized systems. It induces a significant performance overhead due to the 2D page walk it requires, thus 24 memory accesses on a TLB miss (instead of 4 memory accesses in a native system). This 2D page walk constraint comes from the utilization of paging for managing virtual machine (VM) memory. This paper shows that paging is not necessary in the hypervisor. Our solution Compromis, a novel Memory Management Unit, uses direct segments for VM memory management combined with paging for VM’s processes. This is the first time that a direct segment based solution is shown to be applicable to the entire VM memory while keeping applications unchanged. Relying on the 310 studied datacenter traces, the paper shows that it is possible to provision up to 99.99% of the VMs using a single memory segment. The paper presents a systematic methodology for implementing Compromis in the hardware, the hypervisor and the datacenter scheduler. Evaluation results show that Compromis outperforms the two popular memory virtualization solutions: shadow paging and EPT by up to 30% and 370% respectively.
Fri 16 AprDisplayed time zone: Pacific Time (US & Canada) change
08:30 - 10:00
|virtio-mem: Paravirtualized Memory Hot(Un)Plug|
|Efficient LLVM-Based Dynamic Binary Translation|
Alexis Engelke Technical University of Munich, Dominik Okwieka , Martin Schulz Technical University of MunichDOI
|(No)Compromis: Paging Virtualization Is Not a Fatality|
Boris Teabe , Peterson Yuhala , Alain Tchana Toulouse University, France, Fabian Hermenier , Daniel Hagimont Toulouse University, France, Gilles Muller InriaDOI