Merge branch 'slides/update' into 'master'

Slides/update

See merge request !292

slides/problem.md

@@ -855,6 +855,22 @@ Multithreading = false
 
 Defaults to `true`.
 
+## Shared-memory parallelism
+
+Set multithreading backend to e.g. `OpenMP` in `dumux/cmake.opts` before building the modules:
+```cmake
+DUMUX_MULTITHREADING_BACKEND="-DDUMUX_MULTITHREADING_BACKEND=OpenMP"
+```
+Other valid options are: `TBB`,Cpp,`Kokkos`,`Serial`. If left empty, it is automatically set by CMake. If no suitable backend is found, CMake defaults to `Serial`.  
+
+## Shared-memory parallelism
+
+During `dunecontrol`, the chosen backend is displayed in the output via
+```bash
+-- Dumux multithreading backend: OpenMP
+```
+
+
 # Exercises
 
 ## Exercises