Progress Report2014/03/12

AgendaBig-LITTLE Core Scheduling on

Hypervisor◦Simon

Efficient Cost Computation◦You-Cheng

VM Introspection◦Chao-Rui

Big-LITTLE Core Scheduling on HypervisorEnabling power-aware big-LITTLE

scheduler design on ICL Hypervisor(Xvisor)◦Xvisor

An open-source type-1 hypervisor, which aims at providing a monolithic, light-weight, portable, and flexible virtualization solution.

Type-1:Complete monolithic

Further DetailsSchedule vCPU between host

CPU.Hypervisor scheduler may not

interfere Guest OS process scheduler.

Two conditionsGuest OS has big-LITTLE-aware

scheduler◦Hypervisor assign host CPU to guest

according to Guest OS requirements.Guest OS does not have big-

LITTLE-aware scheduler◦Hypervisor scheduler assign vCPU

according to guest condition.

DifficultyIf the scheduler in guest OS is not

big-LITTLE-aware◦Every (virtual) core is the same.◦Load balancing.

Scheduler

ExampleHypervisor will

sees two identical vCPU.

Schedule both vCPU to either big cores or LITTLE cores.

Hyperviosr

Domain 0

vCPU0

vCPU1

T1 T2

T3 T4

Scheduler

What We ExpectHypervisor will

schedule vCPU0 to big core, vCPU1 to LITTLE core.

Hyperviosr

Domain 0

vCPU0

vCPU1

T1 T2

T3 T4

SummaryThe scheduler in guest OS should

be big-LITTLE-aware.◦Avoid load balancing among vCPUs.

If the scheduler in guest OS is not big-LITTLE-aware◦Modify the NICE value of processes

in Guest OS does not help either.◦Try to modify Guest OS process

scheduler.

An Alternative SolutionModify the CPU mask of each

process.◦Limit the vCPU a process can

execute on. ◦“Create” big vCPU and LITTLE vCPU

SchedulerDomain 0

vCPU0

vCPU1

T1 T2

T3 T4

T1 and T2 only sees vCPU0T3 and T4 only sees vCPU1

Current StatusStill trying to develop the big-

LITTLE core scheduling algorithm.