User Guide

Contents

Lock Contention

Metric Description

OpenMP Potential Gain Lock Contention shows elapsed time cost of OpenMP locks and ordered synchronization. High metric value may signal inefficient parallelization with highly contended synchronization objects. To avoid intensive synchronization, consider using reduction, atomic operations or thread local variables where possible. This metric is based on CPU sampling and does not include passive waits.

Possible Issues

When synchronization objects are used inside a parallel region, threads can spend CPU time waiting on a lock release, contending with other threads for a shared resource. Where possible, reduce synchronization by using reduction or atomic operations, or minimize the amount of code executed inside the critical section.

Product and Performance Information

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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.