[Dune] Coarsening of ALUGrid very slow

[Uli Sack]

I did some more timing experiments in order to pinpoint where the time 
goes. In the adapt()-method in dune-grid/grid/alugrid/2d/grid_imp.cc I 
added three timing sections: refine, coarse, updateStatus are timed 
separately. This is the result:

Refine cycle 5:
marking: 0.656041
preAdapt(): 0
ALUGrid; refine time: 15.301
ALUGrid; coarse time: 0.832052
ALUGrid; updateStatus time: 3.46022
adapt() 434779 -> 1665515: 19.5932
postAdapt(): 0.580036
cumulated: 22.8614

Coarsen cycle 0:
marking: 1.13607
preAdapt(): 0
ALUGrid; refine time: 2.10413
ALUGrid; coarse time: 888.58
ALUGrid; updateStatus time: 0.992062
adapt() 1665515 -> 436699: 891.676
postAdapt(): 0.15201
cumulated: 893.528


-- 
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* Uli Sack                     ** email: usack at math.fu-berlin.de       *
* Freie Universität Berlin     ** phone: + 49 (30) 838 75250           *
* Institut für Mathematik      **                                      *
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