Enable multithreading

[nmbader]

Enable multithreading using Base.Threads in the 3D Bspline Jet operator jop_CubicSpline to improve performance.

[samtkaplan]

Thanks! The way that you are adding the IterativeSolvers dep to the tests is incorrect. Instead, it should go in the test/Project.toml file. I think that is why the unit tests are failing. Let me know if you want me to push a commit to this branch to try and fix it.

[samtkaplan]

btw, did this noticibly improve perf?

[nmbader]

btw, did this noticibly improve perf?

I tried with JULIA_NUM_THREADS=44 on a sizable 3D problem and performance was more than 10x.

[nmbader]

Thanks! The way that you are adding the IterativeSolvers dep to the tests is incorrect. Instead, it should go in the test/Project.toml file. I think that is why the unit tests are failing. Let me know if you want me to push a commit to this branch to try and fix it.

Thanks for pointing this out. I moved IterativeSolvers to test/Project.toml