
Solving sparse nonlinear systems of obstacle problems on GPU clusters 341
The function Determine Bordering V ector Elements() (line 5 in Algo-
rithm 18) determines the values of the vector elements shared at the bound-
aries with neighboring computing nodes. Its main operations are as follows:
1. define the values associated to the bordering points needed by the neigh-
bors,
2. copy the values associated to the bordering points from the GPU to the
CPU,
3. exchange the values associated to the bordering points between the
neighboring CPUs, and
4. copy the received values associated to the bordering points from the
CPU to the GPU.
The first operation of this ...