Could the RT patch be interfearing with my ability to run gprof? AFAICT I did everything right to use it, used the -pg on compile for instance, but my profiles have no time at all in them: Flat profile: Each sample counts as 0.01 seconds. no time accumulated % cumulative self self total time seconds seconds calls Ts/call Ts/call name 0.00 0.00 0.00 125000000 0.00 0.00 std::basic_string<char, std::char_traits<char>, std::allocator<char> > std::operator+<char, std::char_traits<char>, std::allocator<char> std::allocator<char> > const&) 0.00 0.00 0.00 500 0.00 0.00 test_append() 0.00 0.00 0.00 500 0.00 0.00 test_printf() 0.00 0.00 0.00 500 0.00 0.00 test_strcat() 0.00 0.00 0.00 500 0.00 0.00 test_add_str() 0.00 0.00 0.00 500 0.00 0.00 test_append_str() 0.00 0.00 0.00 1 0.00 0.00 global constructors keyed to _Z11test_printfv 0.00 0.00 0.00 1 0.00 0.00 __static_initialization_and_destruction_0(int, int) It makes no sense because I know for a fact that these functions are taking measurable time to execute. The only thing I can think of is that the Full on preempt is breaking my profiler.