单选题：Why the kernel can efficiently get the address of a process' PCB
Why the kernel can efficiently get the address of a process' PCB, namely its task_struct?@[D](1)
A. Because thread_info shares two physical pages with the process' stack.
B. Because register ESP maintains the pointer of current process' stack.
C. Because thread_info maintains a pointer to task_struct.
D. All of the above.
A.Because thread_info shares two physical pages with the process' stack.
B.Because register ESP maintains the pointer of current process' stack.
C.Because thread_info maintains a pointer to task_struct.
D.All of the above.
答案：D
A. Because thread_info shares two physical pages with the process' stack.
B. Because register ESP maintains the pointer of current process' stack.
C. Because thread_info maintains a pointer to task_struct.
D. All of the above.
A.Because thread_info shares two physical pages with the process' stack.
B.Because register ESP maintains the pointer of current process' stack.
C.Because thread_info maintains a pointer to task_struct.
D.All of the above.
答案：D