Answer: B. Linux is a microkernel structure.
Answer analysis:
Regarding the description of Linux, we can analyze the correctness of each option one by one based on the known information:
A. The Linux kernel was first released in October 1991:
This description is correct. According to the reference article, the Linux operating system was born on October 5, 1991, which was the date when Linus Torvalds officially announced the birth of the Linux kernel.
B. Linux is a microkernel structure:
This description is wrong. Linux actually uses a monolithic kernel structure, not a microkernel structure. The monolithic kernel structure integrates all system services into the kernel, so that system calls can be executed directly in the kernel space, thereby improving efficiency. The microkernel structure separates system services into multiple independent service processes, which interact through the inter-process communication (IPC) mechanism. Although it improves the modularity of the system, it may also lead to performance degradation.
C. The same application tends to run faster and more efficiently in a UNIX environment than in a Linux environment:
This statement may vary from case to case, but in general, it is not absolute. UNIX and Linux are both Unix-like systems, and they are similar in many aspects, including kernel architecture, system call interface, etc. Therefore, the running speed and efficiency of the same application in UNIX and Linux environments may not differ much, and Linux may even be better in some cases.
However, this also depends on a variety of factors such as the specific application, system configuration, hardware environment, etc.
D. The Linux system was originally based on Unix and aimed to implement the POSIX standard:
This statement is correct. Linux was developed on the basis of Unix, and it inherits many features and design ideas of Unix. At the same time, Linux is also committed to implementing the POSIX (Portable Operating System Interface) standard to ensure its compatibility and portability with other Unix systems.
In summary, the wrong statement is option B: Linux is a microkernel structure. In fact, Linux uses a macrokernel structure.