fem solver issue in parallel
I noticed that using fem's gmres solver the number of iterations increases significantly when increasing the number of processors. I still need to write a test program (only found this using dune-fempy crystal.py example - time dependent non linear PDE, adaptivity turned off):
fem p=1
time used: 45.211201429367065
numOfLinIt: 26501 numOfIt: 1254
time/iteration: 0.0017060
fem p=2
[0] time used: 28.532107830047607
[0] numOfLinIt: 71410 numOfIt: 1255
[1] time used: 28.532469272613525
[1] numOfLinIt: 71410 numOfIt: 1255
time/iteration: 0.00039955
speedup: 1.58
speedup (adjusted for iterations): 4.2
istl p=1
time used: 38.69826364517212
numOfLinIt: 26501 numOfIt: 1254
time/iteration: 0.00146
istl p=2
[0] time used: 21.997411489486694
[0] numOfLinIt: 26501 numOfIt: 1254
[1] time used: 21.997365713119507
[1] numOfLinIt: 26501 numOfIt: 1254
time/iteration: 0.00083
speedup: 1.75