User Guide


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


Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804