CONTEXT

 

TSAR (Tera-Scale Architecture) is a cc-NUMA many-core architecture scalable up to +4000 cores and developed at LIP6 in cooperation with BULL.

ALMOS (Advanced Locality Management Operating System) is new research operating system currently under development at LIP6 laboratory and targeting exclusively cc-NUMA many-cores. It brings new solutions, at the kernel level, for problems related to resources management caused by NUMA characteristics and the large number of cores. The kernel of ALMOS manages hardware resources, memory and processors, in a dynamic and transparent manner to user applications. It allows execution of existing multi-threaded applications without prior modification.

The recent experimental results, show the scalability of ALMOS@TSAR up to 1024 cores. Despite this important and promising results, the DHCCP (Distributed Hybrid Cache-Coherence Protocol) has important power consumption. This energetic drawback is due to L1 write-through strategy (in the other hand, this strategy simplify DHCCP). The goal of this research internship is to implement and experimentally evaluate a new hardware/software co-designed solution to significantly improve performance and power efficiency of TSAR architecture.

WORK PROPOSAL

The student has to make a bibliography focused on directory based cache-coherence protocols. He has to study the DHCCP protocol and TSAR memory management. Next he has to study the specification of proposed solution and its implication on TSAR caches subsystem (L1 and MemCache). Also he has to understand the distributed memory management of ALMOS kernel. After this study phase, the implementation phase of proposed solution can start. The experimental phase should validate the implementation and the integration of new mechanism in TSAR. Finally, The experimental evaluation of this solution should determinate its effective gain in term of performance and power consumption reduction.

DURATION & SUPERVISION

The duration of this full-time research internship is 6 months. It will be conducted at LIP6 laboratory under the supervision of Ghassan Almaless, Mailto: ghassan.almaless@lip6.fr