On Thu, Mar 29, 2012 at 07:58, Dmitry Karpeev <[email protected]> wrote:

I am not sure how to solve the problem of the relationship between KSPReset() and PCReset() when the pc is being shared. How useful are KSPReset() and PCReset() anyway? All but one uses I found were "trivial" -- called from a PCReset_XXX, where XXX uses a KSP internally. The only nontrivial use I found was in VIRS, where the KSP and PC are reset when the active set changes. Would a simple KSPDestroy() do here instead? Perhaps there are uses of KSPReset()/PCReset() in user code, though.

The purpose of all the XXReset() routines is to destroy internal data structures so that the size of the matrix can be changed without needing to reconfigure a new solver. For example, an AMR simulation would change the mesh, create new matrices and vectors, but want to reuse a solver _configuration_.