Performance Analysis and Optimization of User Space versus Kernel Space Network Application

Operating systems such as Linux cater to numerous network applications ranging from daemons that provide services namely HTTPd and SSHd to client programs that access these services. Traditionally, these programs are written in user space and use system calls to switch to the kernel so that operations such as establishing a socket, read or write can be executed. This paper discusses the alternative to the above method which is to implement these user space applications in the kernel. In this research, the performance of LDP implementations of server and client programs in the user space are compared to running them in the kernel space. It proofs the concept that implementing applications in the kernel space reduces the CPL load and enables slightly faster goodput rate due to lesser context-switching between the user and kernel space.