GATE Operating Systems Flashcards
6 cards from real GATE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 GATE Operating Systems flashcards as text
In a demand-paging system, a page fault occurs when:
Answer: A referenced page is not in physical memory
A page fault is triggered when a process accesses a virtual page that is not currently loaded into physical memory.
What is the purpose of a semaphore in operating systems?
Answer: To synchronize concurrent processes
Semaphores are synchronization primitives used to control access to shared resources among concurrent processes.
Which of the following is a non-preemptive CPU scheduling algorithm?
Answer: First Come First Served (FCFS)
FCFS is non-preemptive because once a process starts executing, it runs to completion without being interrupted.
In the context of file systems, what does inode contain?
Answer: File metadata and pointers to data blocks
An inode stores file metadata (size, permissions, timestamps) and pointers to the actual data blocks on disk, but not the filename.
What is thrashing in the context of virtual memory?
Answer: Excessive disk I/O due to constant page swapping
Thrashing occurs when a system spends more time swapping pages in and out of memory than executing actual process instructions.
Which process state transition is NOT valid in a typical OS process state diagram?
Answer: Waiting → Running
A process in the Waiting state must first move to the Ready state after its I/O completes before it can be scheduled to run again.