Hi all, I have a question regarding controlling the number of threads that deal.II uses when run multithreading is enabled. This problem arose because I am now running code on an SMP machine with about 240 cores and a batch system (Torque I believe). My job does not require many cores so I request 4 from the batch system, however when my deal.II code starts it correctly determines that the machine has 240 cores and attempts to use them all. Apart from tying up the cluster, this also means that my own program is very slow.
How can I limit the number of cores that deal.II attempts to use? I believe that this question has come up before, but unfortunately can't find the response. If my memory serves me no real answer came for the question since the person who asked it was not using an SMP machine of this size and it wasn't a real issue. I have testing creating an instance of MultiThreadInfo and setting MultithreadInfo::n_default_threads to 4, but this made no difference. My current best option would be to decide how many cores I want to use once off, modify the source of MultithreadInfo::n_cpus to return that number (since this seems to the value that the number of threads is set from) and recompile. This isn't a very elegant solution and any suggestions are appreciated. Regards, Michael _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
