Does anybody know of a way to lock down individual threads within a Java process to specific CPU cores (on Linux)? I've done this in C, but can't find how to do this in Java. My instincts are that this will require a JNI call, but I was hoping someone here might have some insight or might have done it before.
Thanks!
IMO, this will not be possible unless you use native calls. JVM is supposed to be platform independent, any system calls done to achieve this will not result in a portable code.
The JVM takes care of your threads ... binding threads would more likely cause performance degradation than improvements --i.e., you have absolutely no control over data locality -- why would you want to bind a thread to some core ? Also the Java way of doing things is thread pools -- so even if you had controll over data locality and you had bound your threads cores. If you make use of the pools your tasks will fly around to different threads.
It's not possible (at least with plain Java).
You can use thread pools to limit the amount of threads (and therefore cores) used for different types of work, but there is no way to specify a core to use.
There is even the (small) possibility that your Java runtime doesn't support native threading for your OS or hardware. In this case, green threads are used and only one core will be used for the whole JVM.