8,259 views
4 votes
4 votes

Pre-emptive scheduling is the strategy of temporarily suspending a running process

  1. before the CPU time slice expires
  2. to allow starving processes to run
  3. when it requires I/O
  4. to avoid collision

4 Answers

Best answer
11 votes
11 votes

Answer : Before the CPU time slice expires

In preemptive scheduling tasks are usually assigned with priorities. At times it is necessary to run a certain task that has a higher priority before another task although it is running. Therefore, the running task is interrupted for some time and resumed later when the priority task has finished its execution. This is called preemptive scheduling.

In non-preemptive scheduling, a running task is executed till completion. It cannot be interrupted.

selected by
6 votes
6 votes
Just to add a point,

In this question it looks like the second option can also be the answer but the use of the word 'STARVING' changes everything.

You see, pre-emptive scheduling is about interrupting a low-priority (currently running) process ANYTIME, when a high-priority process enters into ready state. So in a manner it might lead to starving processes of low-priority.

Therefore, pre-emptive scheduling is not the solution to Starvation.

So the solution of Starvation would be AGING i.e., increasing the priority of the low-priority processes in order to make them load into the ready state.
1 votes
1 votes
A.before the CPU time slice expires (Solution)

Preemptive means :---  The os can  take the cpu  from the process without completion .(In mid of Processing)

Non Preemptive :---------- Do not give cpu until completion of that process .
0 votes
0 votes

Option D is irrelevant as far as OS is concerned.

Option C is done in any kind of scheduling, not unique to preemptive.

Option B is wrong, as in a way, most preemptions promote starvation.

Option A seems the most appropriate. It means that before the process has run for the time it was "promised", it could be pulled back.

Answer:

Related questions

6 votes
6 votes
4 answers
1
anitha asked May 25, 2016
9,769 views
In round robin CPU scheduling as time quantum is increased the average turn around timeincreasesdecreasesremains constantvaries irregularly
2 votes
2 votes
2 answers
2
go_editor asked Jul 5, 2016
8,844 views
Consider the following page trace:4,3,2,1,4,3,5,4,3,2,1,5Percentage of page fault that would occur if FIFO page replacement algorithm is used with number of frames for th...
4 votes
4 votes
3 answers
3
go_editor asked Jul 5, 2016
3,853 views
Resources are allocated to the process on non-sharable basis ismutual exclusionhold and waitno pre-emptioncircular wait
1 votes
1 votes
1 answer
4
go_editor asked Jul 4, 2016
2,807 views
Which command is the fastest among the following?COPY TO <NEW FILE>COPY STRUCTURE TO <NEW FILE>COPY FILE <FILE 1 <FILE 2>COPY TO MFILE-DAT DELIMITED