Suppose we run program P in a computer system using the Linux operating system.

Question

Suppose we run program P in a computer system using the Linux operating system. We use the Linux time command to collect some time measurements while P is running. The output from time is, real 53m27.589s user 24m41.850s system 1m3.337s What was the execution time of P? What was the user CPU time of P? What was the system CPU time of P? How much time during the execution of P did the system spend not executing the instructions of P nor OS instructions on behalf of P? List and describe one factor or component of the time from exercise d, i.e., name one thing the system might have been doing during this time period.

Explanation / Answer

a) Execution time is the difference between you started the process and it ended .
So real gives us the elapsed time which is the execution time of P i.e 53m27.589s

b)User time of CPU is the time CPU spent on executing the instructions is user time which is 24m41.850s.

c)System time is the time by on OS (System) i.e 1m3.337s

d) Time that the system spend not executing OS nor the instruction of P
is Real - (System + User) . = 27m42.402s

e) There are lot of process running in the system so the system is executing the other process and our process might be waiting to get the CPU hence the real time is more and it increases if there are more process in the system.



Thanks, let me know if there is any concern.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.