GATE - 2014 | OS | Which one of the following is FALSE? User level threads are not
Posted on 10-02-2022
GATE - 2014 [Operating System]
Question:
Which one of the following is FALSE?
|
A |
User level threads are not scheduled by the kernel. |
|
B |
When a user level thread is blocked, all other threads of its process are blocked. |
|
C |
Context switching between user level threads is faster than context switching between kernel level threads. |
|
D |
Kernel level threads cannot share the code segment. |
Solution:
Option (D) is Correct.
Kernel-level threads share the code segment.
| User-level thread | Kernel level thread |
|---|---|
| User threads are implemented by user processes. | kernel threads are implemented by OS. |
| OS doesn’t recognize user-level threads. | Kernel threads are recognized by OS. |
| Implementation of User threads is easy. | Implementation of the Kernel thread is complicated. |
| Context switch time is less. | Context switch time is more. |
| Context switch requires no hardware support. | Hardware support is needed. |
| If one user-level thread performs a blocking operation then the entire process will be blocked. | If one kernel thread performs a blocking operation then another thread can continue execution. |
| Example: Java thread, POSIX threads. | Example: Window Solaris. |