Embodiments of the present invention provide a system profiler that can be used on any processor architecture. In particular, instead of copying an entire stack every time, the stack is divided into blocks of a fixed size. For each block, a hash value is computed. As stack blocks are sent out of the kernel, the hash value and a copy of the block contents is kept in a user space cache. In the kernel, the hash codes of sent stack blocks are tracked in a table. During system profiling, the kernel module sampling the call stack determines if that stack block was previously sent by checking for the hash value in the kernel table. If the hash matches an entry in the kernel table, then only the hash value is sent. If the hash value is not in the table, the entire block and the hash value is sent.