本次美国代写是一个操作系统的限时测试
T/F Questions
“A system can use either segmentation or paging; but
not both.”
“Consider a system using virtual memory techniques. In
order to maximize the CPU utilization, the kernel should
admit more processes to the main memory if it observes
that the current CPU utilization is low.”
“In a memory reference, it is possible have a TLB hit and
a page fault”
“In an operating system that supports preemptive
user-level scheduling, we must have a preemptive
kernel”
“In general, Operating Systems assign a short time
quantum to high-priority interactive threads because
they are I/O-bound.”
“Most important problem with the contiguous
memory allocation with variable-size partitions
technique is the external fragmentation.”
Q. 13
A certain application runs in 30 minutes on a single
processor PXY system. A close analysis reveals
that 6 minutes of execution is due to inherently
sequential code, while the code for the remaining 24
minutes is fully parallelizable. We consider
upgrading our system to a multi-core PXY system
so as to make the running time at most 10 minutes.
What is the minimum number of cores that we
should use?