PCREDUNDANT#

Runs a KSP solver with preconditioner for the entire problem on subgroups of processors

Options Database Key#

• -pc_redundant_number - number of redundant solves, for example if you are using 64 MPI processes and use an n of 4 there will be 4 parallel solves each on 16 = 64/4 processes.

Notes#

Options for the redundant preconditioners can be set using the options database prefix -redundant_

The default KSP is preonly and the default PC is PCLU or PCCHOLESKY if Pmat is of type MATSBAIJ.

PCFactorSetShiftType() applied to this PC will convey they shift type into the inner PC if it is factorization based.

Developer Note#

PCSetInitialGuessNonzero() is not used by this class but likely should be.

PCCreate(), PCSetType(), PCType, PCRedundantSetScatter(), PCRedundantGetKSP(), PCRedundantGetOperators(), PCRedundantSetNumber(), PCREDISTRIBUTE