Final answer:
An advantage of mapping the entire Linux kernel into every user process's address space is improved performance, particularly due to faster system calls as a result of the monolithic kernel design.
Step-by-step explanation:
The traditional design in Linux where the entire kernel is mapped into the address space of every user process has an advantage in terms of performance. Specifically, this design enables what is known as a monolithic kernel, which can potentially lead to faster system calls because it eliminates the need for context switches between user space and kernel space that are required in microkernel designs.
In a monolithic kernel, since user processes have direct access to the kernel's address space, functions provided by the kernel such as system calls can be performed without the overhead of messaging or switching between different memory spaces. This design is part of what has contributed to Linux's reputation for providing robust performance over the years, especially in server environments where efficiency and speed are crucial.