PCAIRSetProcessorAgglomRatio

Sets the local to non-local nonzero ratio that triggers processor agglomeration in PCAIR

Synopsis

PETSC_EXTERN PetscErrorCode PCAIRSetProcessorAgglomRatio(PC pc, PetscReal input_real)

Logically Collective

Input Parameters

• pc - the PCAIR preconditioner context

• input_real - the local to non-local nonzero ratio that triggers processor agglomeration

Options Database Key

• -pc_air_processor_agglom_ratio ratio - the local to non-local nonzero ratio that triggers processor agglomeration; defaults to 2.0

Note

Only relevant when processor agglomeration is enabled (see PCAIRSetProcessorAgglom()); a level is repartitioned onto fewer ranks once its local to non-local nonzero ratio falls below this value, so a larger ratio triggers agglomeration more readily. Communication-bound problems can benefit from agglomerating sooner.

See Also

KSP: Linear System Solvers, PCAIR, PCAIRGetProcessorAgglomRatio(), PCAIRSetProcessorAgglom(), PCAIRSetProcessorAgglomFactor()

Level

advanced

Index of all PC routines
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Index of all manual pages