* HON LUU: > + Another interesting note is: > + if I remove -fPIC from user space gcc command, then the code compile successfully. However -fPIC is the must for my project. arch_static_branch is useable in the kernel (or kernel modules), but the kernel cannot be compiled with -fPIC. So you have to stop using one thing or the other. This isn't really a GCC question, is more about the kernel build system. Thanks, Florian