Decoupling contention management from scheduling

Johnson, Franklin; Stoica, Radu; Ailamaki, Anastasia; Mowry, Todd C.

doi:10.1145/1736020.1736035

Cited by 30 publications

(34 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To have bounded contention and reduce overheads due to creation and retiring of the threads, it is recommended to maintain a thread pool catering to the functions rather than having each thread for a user/connection. The design of the thread pool and allocating a thread for incoming requests requires careful analysis as the business tier deals with state-full data and ""ordering"" of transactions in some cases would have to be maintained [13] [14].…”

Section: Enhancing Concurrency Of the Critical Path Activitiesmentioning

confidence: 99%

Lean and Efficient Business Tier for Performance Scaling

Natarajan¹,

Sarda²,

Srivastava³

2015

IJCA

View full text Add to dashboard Cite

Large mission critical real-time legacy OLTP systems supporting the service sectors like banking, telecom, and financial services are monolithic in nature and thereby not flexible to enable business transformation which is the need of the hour due to emerging dynamic changes to business ecosystem. Broadly speaking, these large mission critical applications can be classified into three stages of activities: pre-processing, core business processing and post processing activities.This paper focuses on making the Business processing activities tier lean and efficient. By leveraging recent advances in technologies, a methodology is described by which the OLTP applications can be successfully transformed into agile systems. The methodology enables a view of the Business Tier in five dimensions. The first dimension is identifying the business"s core critical path and how to make it lean. The second dimension is how to enhance concurrency of the activities in the critical path. The third dimension is to improve the parallelism in execution of concurrency. The fourth is to separate I/O operations off the critical path. The fifth being how to minimize contentions for shared resources to ensure higher efficiencies. The paper also presents, the results of the experiments carried out by applying the above recommendation and the performance improvements to decide the optimal setup for an environment for given workload.Addressing the five dimensions of Business Tier, this paper demonstrates the transformation that can be achieved which will enable the business to be agile and respond to market ecosystem demands in a very efficient and effective manner.

show abstract

Section: Enhancing Concurrency Of the Critical Path Activitiesmentioning

confidence: 99%

Lean and Efficient Business Tier for Performance Scaling

Natarajan¹,

Sarda²,

Srivastava³

2015

IJCA

View full text Add to dashboard Cite

show abstract

“…The observed degradation in these workloads is a result of multiplexing all threads on a single core. The resulting oversubscribed system is prone to known pathologies from contention on synchronization, load imbalance, convoying, and frequent context switches [9,25,28,29,50]. Demonstrating the penalty of oversubscription.…”

Section: Mitigating Overheads Of Truncated Sprintsmentioning

confidence: 99%

Computational sprinting on a hardware/software testbed

et al. 2013

View full text Add to dashboard Cite

CMOS scaling trends have led to an inflection point where thermal constraints (especially in mobile devices that employ only passive cooling) preclude sustained operation of all transistors on a chipa phenomenon called "dark silicon." Recent research proposed computational sprinting-exceeding sustainable thermal limits for short intervals-to improve responsiveness in light of the bursty computation demands of many media-rich interactive mobile applications. Computational sprinting improves responsiveness by activating reserve cores (parallel sprinting) and/or boosting frequency/voltage (frequency sprinting) to power levels that far exceed the system's sustainable cooling capabilities, relying on thermal capacitance to buffer heat.Prior work analyzed the feasibility of sprinting through modeling and simulation. In this work, we investigate sprinting using a hardware/software testbed. First, we study unabridged sprints, wherein the computation completes before temperature becomes critical, demonstrating a 6.3× responsiveness gain, and a 6% energy efficiency improvement by racing to idle. We then analyze truncated sprints, wherein our software runtime system must intervene to prevent overheating by throttling parallelism and frequency before the computation is complete. To avoid oversubscription penalties (context switching inefficiencies after a truncated parallel sprint), we develop a sprint-aware task-based parallel runtime. We find that maximal-intensity sprinting is not always best, introduce the concept of sprint pacing, and evaluate an adaptive policy for selecting sprint intensity. We report initial results using a phase change heat sink to extend maximum sprint duration. Finally, we demonstrate that a sprint-and-rest operating regime can actually outperform thermally-limited sustained execution.

show abstract

“…In the implementation of synchronization primitives, blocking is sometimes used to give up the processor when waiting for the primitive takes too long. While blocking is definitely a part of lock contention, it is also arguably a part of scheduling, as effectively argued in the work by Johnson [8]. Essentially, the action of giving up the processor to make way for other threads is a scheduling activity, and it may be more convenient, for performance debugging purposes, to treat it as such.…”

Section: A Measuring Software-induced Overheadmentioning

confidence: 99%

“…If, for example, the number of threads exceeds the number of available cores, then the performance of a spin barrier can degrade drastically. A dynamic locking primitive that switches between spinning and blocking implementation depending on the number of runnable threads has been proposed by Johnson [8] and could be used in this case.…”

Section: Inefficient Barrier Implementationmentioning

confidence: 99%

Deconstructing the overhead in parallel applications

Roth

Best²,

Mustard

et al. 2012

2012 IEEE International Symposium on Workload Characterization (IISWC)

View full text Add to dashboard Cite

Abstract-Performance problems in parallel programs manifest as lack of scalability. These scalability issues are often very difficult to debug. They can stem from synchronization overhead, poor thread scheduling decisions, or contention for hardware resources, such as shared caches. Traditional profiling tools attribute program cycles to different functions, but do not generate immediate insight into issues limiting scalability. Profiling information is very program-specific and is usually processed manually by a human expert in a time-consuming and cumbersome process.Our experience in tuning performance of parallel applications led us to discover that performance tuning can be considerably simplified, and even to some degree automated, if profiling measurements are organized according to several intuitive performance factors common to most parallel programs. In this work we present these factors and propose a hierarchical framework composing them. We present three case studies where analyzing profiling data according to the proposed principle led us to improve performance of three parallel programs by a factor of 6-20×. Our work lays foundation for new ways of organizing and visualizing profiling data in performance tuning tools.

show abstract

Decoupling contention management from scheduling

Cited by 30 publications

References 21 publications

Lean and Efficient Business Tier for Performance Scaling

Lean and Efficient Business Tier for Performance Scaling

Computational sprinting on a hardware/software testbed

Deconstructing the overhead in parallel applications

Contact Info

Product

Resources

About