of a send buffer Intel® Trace Collector will read each byte in the buffer once. This works for contiguous as well as non-contiguous data types. If any byte cannot be read because the memory is inaccessible, a
is reported. This is an error because it is only possible to proceed by skipping the entire operation.
check also disables the accessibility check and send operations are then treated like receive operations: for receive operations no similar check is performed because the MPI standard does not say explicitly that the whole receive buffer has to be accessible - only the part into which an incoming message actually gets copied must be writable. Violations of that rule are caught and reported as fatal