Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used is First Come First Served $$(FCFS).$$ If $$FCFS$$ is replaced by Shortest Seek Time First $$(SSTF),$$ claimed by the vendor to give $$50\% $$ better benchmark results, what is the expected improvement in the $${\rm I}/O$$ performance of user programs?

Consider the following set of processes, with the arrival times and the $$CPU$$-burst times given in milliseconds.

What is the average turnaround time for these processes with the preemptive shortest remaining processing time first $$(SRTF)$$ algorithm?

Consider the following statements with respect to user-level threads and kernel-supported threads.
i) Context switch is faster with kernel- supported threads
ii) For user-level threads, a system call can block the entire process
iii) Kernel-supported threads can be scheduled independently
iv) Use-level threads are transparent to the kernel

Which of the above statements are true?

Consider the following C program segment:

char p[20];
char *s = "string";
int length = strlen(s);
for(i=0; i < length; i++)
  p[i] = s[length-i];
printf("%s",p);

The output of the program is