PipeliningIssues
Revision as of 08:31, 4 September 2019 by Daniel-schurhoff-de23@rwth-aachen.de (talk | contribs)
Description
Modern CPU cores use pipelines to overlap different instructions to optimally distribute work over the execution units. The pattern "Pipelining issues" describes a problem in the pipeline which causes the reduction of the overlap and consequently less utilization.
Symptoms
- In-core throughput far away from design limit
- performance insensitive to data set size
Detection
- Large integral ratio of cycles to specific instruction count(s)
- bad (high) CPI
LIKWID performance groups: FLOPS_DP, FLOPS_SP, DATA and CLOCK