only rebuild the JacobiPC blocks when the reference state has changed

asQ/preconditioners/jacobipc.py

@@ -138,7 +138,8 @@ def initialize(self, pc):
  # The block rhs/solution are the timestep i of the
  # input/output AllAtOnceCofunction/Function
  block_problem = fd.LinearVariationalProblem(A, self._x[i], self._y[i],
- bcs=self.block_bcs)
+ bcs=self.block_bcs,
+ constant_jacobian=True)
  block_solver = fd.LinearVariationalSolver(block_problem,
  appctx=appctx_h,
  options_prefix=block_prefix)
@@ -169,7 +170,7 @@ def update(self, pc):
  st.assign(ft)
 
  if jacobian_state == 'linear':
- pass
+ return
 
  elif jacobian_state == 'current':
  state_func.assign(aaofunc)
@@ -199,6 +200,9 @@ def update(self, pc):
  elif jacobian_state == 'user':
  pass
 
+ for block in self.block_solvers:
+ block.invalidate_jacobian()
+
  return
 
  @profiler()