hayakawa16
commented
4 years ago There is renewed interest. In the link above, 2 methods are described: 1) Threadpool, 2) Parallel.For. I tried the Parallel.For because it is easy to add around the MonteCarloSimulation.cs for loop that loops over each photon.
I first tried on a linux 18 core, 2 threads per core machine. Without any code modifications N=1e6 photons took 1/2 hour to run. This machine utilizes the threads on its own and typically I see 8-12 threads being used during a simulation. With the code fix the code took 1.7 hours! Not sure why. I thought possibly the threading management was conflicting with the parallelized code somehow.
So I tried the same on a linux computer with 4 cores, no threads. Without the code fix N=1e6 took about an hour. With the code fix, the code compiles but the many unit tests fail.
The Threadpool requires a larger code modification. I will look into this method and continue searching for other options.
dcuccia
I would like to explore how we might modify the code so that individual batches of photons can be executed on different processors then added back together for a final tally. I've been reading this: https://www.codeproject.com/Articles/767997/Parallelised-Monte-Carlo-Algorithms-sharp under the section "C# Threadpool" as a possible model to follow.