Method: allocate_wrk

call p%allocate_wrk(info[, vmold])

Allocate internal work vectors. Each application of the preconditioner uses a number of work vectors which are allocated internally as necessary; therefore allocation and deallocation of memory occurs multiple times during the execution of a Krylov method. In most cases this strategy is perfectly acceptable, but on some platforms, most notably GPUs, memory allocation is a slow operation, and the default behaviour would lead to a slowdown. This method allows to trade space for time by preallocating the internal workspace outside of the invocation of a Krylov method. When using GPUs or other specialized devices, the vmold argument is also necessary to ensure the internal work vectors are of the appropriate dynamic type to exploit the accelerator hardware; when allocation occurs internally this is taken care of based on the dynamic type of the x argument to the apply method.

Arguments

info	integer, intent(out).
	Error code. If no error, 0 is returned. See Section 8 for details.
vmold	class(psb_x_base_vect_type), intent(in), optional.
	The desired dynamic type for internal vector components; this allows e.g. running on GPUs.