Hello, > > > Does anyone know if it is possible to get the ID of the core which is > > executing code at a given point in a C++ program? I'm running code built > > using gcc 4.4.1 on Ubuntu Koala 64-bit with an Intel core 2 quad and would > > like to see whether external code calling a function in a shared library is > > making use of multiple cores. > > This isn't a gcc question. The compiler doesn't know anything about > different cores. I say this not to chastise you, but to let you know > that you are more likely to get the answer if you ask on a more > appropriate forum. The answer may be operating system specific. I don't know a system-independent solution, however on Linux the easiest way is probably to read it from /proc/PID/stat. It should be the column 39 (?) - see "man 5 proc": processor %d (since Linux 2.2.8) CPU number last executed on. But I'm not sure whether you can get this information also for multiple threads sharing the same process-ID? That might depend on the threading library used. Axel