复旦大学计算机科学技术学院0S试题

1、复旦大学计算机科学技术学院2 0 1 1 - 2 0 1 2学年第一学期操作系统期末考试试卷A卷共8页2012年1月课程代码：C O M P 1 3 0 0 0 8 . 0 1 - 0 4考试形式：口开卷口/闭卷(本试卷答卷时间为120分钟，答案必须写在试卷上，做在草稿纸上无效)NO aids (books, notes, discussion etc.) are allowed. Ask the instructor if you have any questions.Student ID Name ScoreQuestion 1 2 3 4 SumScore1. Choice (36%)

2、fill in the blank with ONE most suitable answerWhich of the following statements on memory management are NOT true.()For each address translation, the system with TLB is definitely faster than without TLB.TLB is transparent to application.A TLB miss will definitely result in disk operation to swap i

3、n the pageA page table is still needed though TLB can achieve fast address translation.A semaphore s is initialized as 2. After four processes (P1, P2, P3, and P4) have donethe following operations sequentially:(P1, wait(s).(P2, wait(s).P3,wait(s).P4, signal(s).which process is in BLOCK state?()A no

4、neB P1C P2D P3When designing a disk scheduling policy, which factor has the most significant impacton the disk I/O performance?( )Latency of moving the disk headTime required to read one sector from the diskThe average rotational delayThe maximal rotational delayA UNIX file system has 4-KB blocks an

5、d 4-byte disk addresses. The inode of file X requires 10 direct entries and one indirect block which is half full. How large is the file in blocks?( ) TOC o 1-5 h z 182665221034Among following scheduling types, which pair are mainly used to adjust the degree ofmultiprogramming? ()Long-term schedulin

6、g, and mid-term schedulingLong-term scheduling, and short-term schedulingShort-term scheduling, and mid-term schedulingShort-term scheduling, and disk schedulingWhich layer of I/O software issues a sequence of commands to the device controller?()User-space I/O softwareDevice Independent I/O software

7、Device driverInterrupt handlerIn a pure user-level threads (ULTs) system, there is a process with 3 threads. Whichone of the following statements is correct? ()In a multiprocessor system, the 3 ULTs may be running at the same timeWhen one ULT in the process is in running state, it is certain that th

8、e process is holding a processorWhen the process is in ready state, one thread may be in running stateWhen one thread issues a blocked system call, another thread in the process may be scheduled to run.A Linux file whose owner has UID = 12 and GID = 1 has mode rwxr-x. Tom with UID=6, GID = 1 tries t

9、o do some operations for the file, which one of the following operations is feasible? ()Tom can read/write/execute the file.Tom can read the file, but can not write the file.Tom cannot execute any of the read/write/execute operation.Tom can write the file, but not read/execute the file.A computer ha

10、s 6 tape drives, with n processes competing for them. Each process may need two drives. For which maximal values of n is the system deadlock free?() TOC o 1-5 h z 3456Which one of the following actions is effective when thrashing is happening in acomputer system? ()Destroy some processesIncrease the

11、 size of disk swapping spaceIncrease the priorities of user processesUpgrade the system with a high-speed CPUWhich one of the following scheduling algorithms is non-preemptive and does NOTsuffer from starvation? ()Static Priority-basedHighest Response Ratio NextRound RobinShortest Process Next(SJF)Which one of the following events may cause the running process to be put back intothe ready queue? ()An interrupt from I/O devices has occurred.The proce