Compilation notes

If you are lucky, then pkg-config may work for you. If not, I found the following necessary (with StarPU installed in ~/starpu).

STARPU_DIR=~/starpu
export CPATH=$STARPU_DIR/include/starpu/1.4/:$CPATH
export LD_LIBRARY_PATH=$STARPU_DIR/lib/:$LD_LIBARY_PATH
export PKG_CONFIG_PATH=$STARPU_DIR/lib/pkgconfig/:$PKG_CONFIG_PATH

To use only GPU (no hybrid)

Change the .where field of the starpu_codelet to remove STARPU_CPU.

Results for mandelbrot

STARPU_SCHED=dmdas works slightly better than the default, although the difference is not great.

Linear speedup when using two GPUs exclusively (but -nblocks must be pretty low, e.g. 20), but significant slowdown when CPU is also used.

$ ./mandelbrot -nblocks 20 -niter 10 -max_iter 10000 -height 20000 -width 20000

The self-tuning of STARPU_SCHED=dmdas seems to make StarPU just disregard the CPU on subsequent invocations.

spmv

I had to modify the code slightly to work with CBLAS. It seemed to be missing necessary includes in the upstream version.