An SMT-Selection Metric to Improve Multithreaded Applications' Performance

Funston, Justin; Maghraoui, Kaoutar El; Jann, Joefon; Pattnaik, Pratap; Fedorova, Alexandra

doi:10.1109/ipdps.2012.125

Cited by 7 publications

(2 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A different approach is followed by Saez et al [25], who propose a non-work-conserving scheduler that greatly speedups critical threads while still achieving slight throughput improvements on ST and SMT multicores. Also targeting SMT multicores but focused on multithreaded applications, Funston et al [26] propose an SMT metric to select the optimal number of threads per core depending on the instruction mix of the application.…”

Section: Related Workmentioning

confidence: 99%

Perf&Fair: A Progress-Aware Scheduler to Enhance Performance and Fairness in SMT Multicores

Feliu

Sahuquillo

Petit

et al. 2017

IEEE Trans. Comput.

View full text Add to dashboard Cite

Nowadays, high performance multicore processors implement multithreading capabilities. The processes running concurrently on these processors are continuously competing for the shared resources, not only among cores, but also within the core. While resource sharing increases the resource utilization, the interference among processes accessing the shared resources can strongly affect the performance of individual processes and its predictability. In this scenario, process scheduling plays a key role to deal with performance and fairness. In this work we present a process scheduler for SMT multicores that simultaneously addresses both performance and fairness. This is a major design issue since scheduling for only one of the two targets tends to damage the other. To address performance, the scheduler tackles bandwidth contention at the L1 cache and main memory. To deal with fairness, the scheduler estimates the progress experienced by the processes, and gives priority to the processes with lower accumulated progress. Experimental results on an Intel Xeon E5645 featuring six dual-threaded SMT cores show that the proposed scheduler improves both performance and fairness over two state-of-the-art schedulers and the Linux OS scheduler. Compared to Linux, unfairness is reduced to a half while still improving performance by 5.6%.

show abstract

Section: Related Workmentioning

confidence: 99%

Perf&Fair: A Progress-Aware Scheduler to Enhance Performance and Fairness in SMT Multicores

Feliu

Sahuquillo

Petit

et al. 2017

IEEE Trans. Comput.

View full text Add to dashboard Cite

show abstract

“…There were algorithms that scheduled threads so as to minimize contention for shared caches, memory controllers and multithreaded CPU pipelines [8,9,24,29,34,42,46]. There were algorithms that reduced communication distance among threads sharing data [41] and determined the optimal number of cores to allocate to multithreaded workloads [17]. There were algorithms that addressed the scheduling of threads on asymmetric multicore CPUs [22,35] and algorithms that integrated scheduling with the management of power and temperature [19].…”

Section: Lessons Learnedmentioning

confidence: 99%

The Linux scheduler

Lozi

Lepers

Funston

et al. 2016

Proceedings of the Eleventh European Conference on Computer Systems

Self Cite

View full text Add to dashboard Cite

As a central part of resource management, the OS thread scheduler must maintain the following, simple, invariant: make sure that ready threads are scheduled on available cores. As simple as it may seem, we found that this invariant is often broken in Linux. Cores may stay idle for seconds while ready threads are waiting in runqueues. In our experiments, these performance bugs caused many-fold performance degradation for synchronization-heavy scientific applications, 13% higher latency for kernel make, and a 14-23% decrease in TPC-H throughput for a widely used commercial database. The main contribution of this work is the discovery and analysis of these bugs and providing the fixes. Conventional testing techniques and debugging tools are ineffective at confirming or understanding this kind of bugs, because their symptoms are often evasive. To drive our investigation, we built new tools that check for violation of the invariant online and visualize scheduling activity. They are simple, easily portable across kernel versions, and run with a negligible overhead. We believe that making these tools part of the kernel developers' tool belt can help keep this type of bug at bay.

show abstract