No abstract

This paper presents vCAT, a novel design for dynamic shared cache management on multicore virtualization platforms based on Intel's Cache Allocation Technology (CAT). Our design achieves strong isolation at both task and VM levels through cache partition virtualization, which works in a similar way as memory virtualization, but has challenges that are unique to cache and CAT. To demonstrate the feasibility and benefits of our design, we provide a prototype implementation of vCAT, and we present an extensive set of microbenchmarks and performance evaluation results on the PARSEC benchmarks and synthetic workloads, for both static and dynamic allocations. The evaluation results show that (i) vCAT can be implemented with minimal overhead, (ii) it can be used to mitigate shared cache interference, which could have caused task WCET increased by up to 7.2 x, (iii) static management in vCAT can increase system utilization by up to 7 x compared to a system without cache management; and (iv) dynamic management substantially outperforms static management in terms of schedulable utilization (increase by up to 3 x in our multi-mode example use case). Abstract-This paper presents vCAT, a novel design for dynamic shared cache management on multicore virtualization platforms based on Intel's Cache Allocation Technology (CAT). Our design achieves strong isolation at both task and VM levels through cache partition virtualization, which works in a similar way as memory virtualization, but has challenges that are unique to cache and CAT. To demonstrate the feasibility and benefits of our design, we provide a prototype implementation of vCAT, and we present an extensive set of microbenchmarks and performance evaluation results on the PARSEC benchmarks and synthetic workloads, for both static and dynamic allocations. The evaluation results show that (i) vCAT can be implemented with minimal overhead, (ii) it can be used to mitigate shared cache interference, which could have caused task WCET increased by up to 7.2×, (iii) static management in vCAT can increase system utilization by up to 7× compared to a system without cache management; and (iv) dynamic management substantially outperforms static management in terms of schedulable utilization (increase by up to 3× in our multi-mode example use case). Disciplines Computer Engineering | Computer Sciences

We introduce gFPca, a cache-aware global pre-emptive fixed-priority (FP) scheduling algorithm with dynamic cache allocation for multicore systems, and we present its analysis and implementation. We introduce a new overhead-aware analysis that integrates several novel ideas to safely and tightly account for the cache overhead. Our evaluation shows that the proposed overhead-accounting approach is highly accurate, and that gFPca improves the schedulability of cache-intensive tasksets substantially compared to the cache-agnostic global FP algorithm. Our evaluation also shows that gFPca outperforms the existing cache-aware non-preemptive global FP algorithm in most cases. Through our implementation and empirical evaluation, we demonstrate the feasibility of cache-aware global scheduling with dynamic cache allocation and highlight scenarios in which gFPca is especially useful in practice. Abstract-We introduce gFPca, a cache-aware global preemptive fixed-priority (FP) scheduling algorithm with dynamic cache allocation for multicore systems, and we present its analysis and implementation. We show that a naïve extension of existing overhead analysis techniques can lead to unsafe results, and we introduce a new overhead-aware analysis that integrates several novel ideas to safely and tightly account for the cache overhead. Our evaluation shows that the proposed overheadaccounting approach is highly accurate, and that gFPca not only improves schedulability of cache-intensive tasksets substantially compared to the cache-agnostic global FP algorithm but also outperforms the existing cache-aware non-preemptive global FP algorithm in most cases. Through our implementation and empirical evaluation, we demonstrate the feasibility of cacheaware global scheduling with dynamic cache allocation and highlight scenarios in which gFPca is especially useful in practice.

No abstract

Proxy Mobile IPv6 (PMIPv6) is proposed as a new network-based mobility protocol and it does not require MN's involving in mobility management. MN can handover relatively faster in PMIPv6 than in Mobile IPv6 (MIPv6) because it actively uses link-layer attachment information and reduces the movement detection time, and eliminates duplicate address detection procedure. However, the current PMIPv6 cannot prevent packet loss during the handover period. We propose the Smart Buffering scheme for seamlessness in PMIPv6. The Smart Buffering scheme prevents packet loss by proactively buffering packets that will be lost in a current serving mobile access gateway (MAG) by harnessing network-side information only. It also performs redundant packet elimination and packet reordering to minimize duplicate packet delivery and disruption of connection-oriented flows. To fetch buffered packets from a previous MAG, a new MAG discovers the previous MAG by using a discovery mechanism without any involvement of an MN. We verified the effectiveness of Smart Buffering via simulation with various parameters.