Difference between revisions of "ControlFlowIssues"

From HPC Wiki
Jump to navigation Jump to search
m
 
Line 1: Line 1:
 +
[[Category:Performance Pattern]]
 
== Description ==
 
== Description ==
 
The pattern "Control flow issues" describes the case then the CPU core has to jump around in the instruction stream and bad prediction of condition evaluation
 
The pattern "Control flow issues" describes the case then the CPU core has to jump around in the instruction stream and bad prediction of condition evaluation

Latest revision as of 16:13, 3 September 2019

Description

The pattern "Control flow issues" describes the case then the CPU core has to jump around in the instruction stream and bad prediction of condition evaluation

Symptoms

  • In-core throughput far away from design limit
  • performance insensitive to data set size


Detection

  • High branch rate
  • High ratio of mispredicted branches

LIKWID performance groups: BRANCH

Possible optimizations and/or fixes

  • Avoid conditions in inner loops


Applicable applications or algorithms or kernels