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[Johan Hake <668862@xxxxxxxxxxxxxxxxxx>]

> What about valgrind --tool=callgrind and then kcachegrind? No need for
> any special profiling flags.
> 
> Make sure to set CGAL_DISABLE_ROUNDING_MATH_CHECK.

Most time is spent in SparsityPattern::insert.

It really looks like the random access to the set object diagonal is taking 
its toll here.         

I guess it is this line that takes time:

   diagonal[I].insert(map_j[j]);

Because std::set::insert is inlined I cannot explicitly follow that call. But 
there are some if tests within that call that takes an awfull lot of time when 
the real space is used.

Johan

-- 
Sparsity pattern computation dead slow with 'real' spaces
https://bugs.launchpad.net/bugs/668862
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Status in DOLFIN: New

Bug description:
The computation of the sparsity pattern is dead slow when real spaces are used, i.e.,

    R = FunctionSpace(mesh, 'R', 0)

To see the problem, compare the neumann-poisson and poisson demos with fine meshes (256x256)