Rethinking Communication in Multiple-kernel OSes for New Shared Memory Interconnects

Abstract

Future computer platforms will likely be built with a multitude of on-chip and off-chip processing units being potentially of different ISAs, OS-capable, and sharing memory with a form of consistency. Multiple-kernel OSes, from multikernels to single-system image OSes, have been demonstrated to mange such platforms efficiently, but they assume no shared memory between kernels as a founding principle. This position paper proposes a new multiple-kernel OS design, which leverages consistent shared memory across homogeneous and heterogeneous processing units in a machine. Among other benefits, this design enables porting commodity SMP OSes to such future platforms, capitalizing on their shared memory programming model, and extend them to multiple-kernel OSes. Herein we present such design, based on two new software primitives tackling the problem of sharing and data format differences between eventually heterogeneous computing units: typed shared memory and type-morphable executable code. We also describe an initial implementation built around Popcorn Linux for x86 and ARM.