Module distributed 

Row-partitioned HOST FP64 preconditioned CG. Matrix rows stay partitioned; search vectors are all-gathered, scalars globally reduced. No device/RDMA claim.

Structs

DistributedCgReport

DistributedCsr

LocalCommunicator

RowPartition

Traits

SolverCommunicator

Ordered blocking communicator. All ranks call the same solve in the same order. all_gather_fixed returns one equally-sized buffer PER rank, in rank order. abort MUST wake pending peers (or transport must have a finite timeout).

Functions

distributed_cg

Solve SPD A x=b with balanced contiguous row partitioning. optional Jacobi is local diagonal scaling. No checkpoint/restart inside a solve: an error aborts the communicator; create a fresh communicator before retrying.