Recent questions tagged operating-system / GATE Overflow for GATE CSE

2 votes

2 answers

2551

memory management
True or False S1: In Fixed partition we have both internal and external fragmentation S2: In variable partition, we have only external fragmentation

True or FalseS1: In Fixed partition we have both internal and external fragmentationS2: In variable partition, we have only external fragmentation

cse7

1.1k views

cse7 asked Nov 22, 2016

3 votes

1 answer

2552

fork() system call
MY QUESTION IS 1)WHY PRINTF() PRINT VIRTUAL ADDRESS(MENTIONED IN EXPLANTION) NOT PHYSICAL ADDRESS 2) WHY VIRTUAL ADDRESS(O/P OF PRINTF(&VAR)) OF A VARIABLE CHANGES WHEN WE RUN A PROGRAM MANY TIMES Consider the following code fragment: if (fork() = ... process and virtual address of a' doesn't change in child process. Therefore, we get same addresses in both parent and child.

MY QUESTION IS1)WHY PRINTF() PRINT VIRTUAL ADDRESS(MENTIONED IN EXPLANTION) NOT PHYSICAL ADDRESS2) WHY VIRTUAL ADDRESS(O/P OF PRINTF(&VAR)) OF A VARIABLE CHANGES WHEN WE ...

indrajeet

1.9k views

indrajeet asked Nov 20, 2016

0 votes

2 answers

2553

OS Doubt
Need explanation of Long term Scheduler , Short term Scheduler and Medium term scheduler Please give me the detailed explanation since many websites are defining each of these in their own way

Need explanation of Long term Scheduler , Short term Scheduler and Medium term schedulerPlease give me the detailed explanation since many websites are defining each of t...

Prajwal Bhat

881 views

Prajwal Bhat asked Nov 20, 2016

3 votes

2 answers

2554

MadeEasy Test Series: Operating System - Disks
A certain hard disk rotates at 6000 rpm. It has 1 KB per sector and average 64 sectors/track and has a seek time of 5 msec. Which of the following statements is/are true? S1 : The data transfer rate of the drive is 6400 KBPs. S2 : The ... S3 : The time required to read 800 successive sectors is 0.0052 sec. Only S1 and S2 Only S2 and S3 Only S2 Only S1

A certain hard disk rotates at 6000 rpm. It has 1 KB per sector and average 64 sectors/track and has a seek time of 5 msec. Which of the following statements is/are true?...

Pankaj Joshi

1.6k views

Pankaj Joshi asked Nov 19, 2016

30 votes

2 answers

2555

GATE CSE 1990 | Question: 2-iii
Match the pairs:$\begin{array}{|ll|ll|}\hline (a) & \text{Critical region} & (p) & \text{Hoare's monitor} \\ (b) & \text{Wait/Signal} & (q) & \text{Mutual exclusion} \\ (c) & \text{Working Set} & (r) & \text{Principle of locality} \\ (d) & \text{Deadlock} & (s) & \text{Circular Wait} \\\hline \end{array}$

Match the pairs:$$\begin{array}{|ll|ll|}\hline (a) & \text{Critical region} & (p) & \text{Hoare's monitor} \\ (b) & \text{Wait/Signal} & (q) & \text{Mutual exclusion} \\ ...

makhdoom ghaya

6.1k views

makhdoom ghaya asked Nov 18, 2016

22 votes

1 answer

2556

GATE CSE 1990 | Question: 1-vii
Semaphore operations are atomic because they are implemented within the OS _________.

Semaphore operations are atomic because they are implemented within the OS _________.

makhdoom ghaya

7.9k views

makhdoom ghaya asked Nov 18, 2016

33 votes

1 answer

2557

GATE CSE 1990 | Question: 1-vi
The highest-response ratio next scheduling policy favours ___________ jobs, but it also limits the waiting time of _________ jobs.

The highest-response ratio next scheduling policy favours ___________ jobs, but it also limits the waiting time of _________ jobs.

makhdoom ghaya

5.8k views

makhdoom ghaya asked Nov 18, 2016

23 votes

1 answer

2558

GATE CSE 1990 | Question: 1-v
Under paged memory management scheme, simple lock and key memory protection arrangement may still be required if the _________ processors do not have address mapping hardware.

Under paged memory management scheme, simple lock and key memory protection arrangement may still be required if the _________ processors do not have address mapping hard...

makhdoom ghaya

5.9k views

makhdoom ghaya asked Nov 18, 2016

1 votes

1 answer

2559

Time required to read 800 successive sectors ?
A certain hard disk rotates at 6000 rpm. It has 1KB per sector and 64 sectors per track and has a seek time of 5ms. The time required to read 800 successive sectors is? 800 successive sectors means 12 complete tracks and 32 sectors of the 13th track. (this is not random 800 sectors that we can just multiply by 800 , with tseek+trot+ttrans).

A certain hard disk rotates at 6000 rpm. It has 1KB per sector and 64 sectors per track and has a seek time of 5ms. The time required to read 800 successive sectors is?80...

prasitamukherjee

951 views

prasitamukherjee asked Nov 16, 2016

3 votes

3 answers

2560

MADE EASY TEST SERIES
Consider the following table of arrival time and burst time for three processes P1, P2 and P3. Suppose that a fourth process P4 enters the system at time 7.6 sec and needs 6 sec of CPU time. Also assume that P2, P3 are interactive and P1, ... from the interactive queue followed by one process (if available) from the batch queue etc. What will be the average turnaround time ?

Consider the following table of arrival time and burst time for three processes P1, P2 and P3.Suppose that a fourth process P4 enters the system at time 7.6 sec and needs...

User007

3.6k views

User007 asked Nov 15, 2016

13 votes

1 answer

2561

GATE CSE 1987 | Question: 8a
Consider the following proposal to the "readers and writers problem." Shared variables and semaphores: aw, ar, rw, rr : interger; mutex, reading, writing: semaphore: initial values of variables and states of semaphores: ar=rr=aw ... group of readers make waiting writers starve? Can writers starve readers? Explain in two sentences why the solution is incorrect.

Consider the following proposal to the "readers and writers problem."Shared variables and semaphores:aw, ar, rw, rr : interger; mutex, reading, writing: semaphore: initia...

makhdoom ghaya

3.1k views

makhdoom ghaya asked Nov 14, 2016

2 votes

1 answer

2562

MADE EASY TEST SERIES
A file system with 512 GB disk uses a file descriptor with 16 direct block addresses, 1 indirect block address, 1 doubly indirectly block address and 1 triple indirect block addresses. Size of each disk block is 256 bytes and the size of each disk ... 8 bytes. The maximum possible file size is __________ (in MB). Which topic does the above question belong to? Please guide.

A file system with 512 GB disk uses a file descriptor with 16 direct block addresses, 1 indirect block address, 1 doubly indirectly block address and 1 triple indirect bl...

User007

951 views

User007 asked Nov 14, 2016

1 votes

1 answer

2563

MadeEasy Test Series: Operating System - Process
Q. A process spends 25% of its time waiting for I/O to complete. if 3 process in memory at a time, then the probability of CPU utilized(assume all I/O process are overlapped) is...................... so here 2 solution plz check first one why not correct 1. 1 - [ (3C1 * ... (.75)^2 + (3C2 *(.25)^2* (.75) + (3C3 *(.25)^3* ) 2. 1 - [ (3C3 *(.25)^3* ) ]

Q. A process spends 25% of its time waiting for I/O to complete. if 3 process in memory at a time, then the probability of CPU utilized(assume all I/O process are overlap...

Hradesh patel

659 views

Hradesh patel asked Nov 14, 2016

3 votes

1 answer

2564

Disk capacity
Assume innermost track has diameter 1 cm and outermost track has diameter 10 cm. There are 10 tracks in the disk and it is rotating with constant linear velocity. Capacity of innermost track is 1MB. Total capacity of the disk is ____ ?

Assume innermost track has diameter 1 cm and outermost track has diameter 10 cm. There are 10 tracks in the disk and it is rotating with constant linear velocity. Capacit...

Rakesh K

1.7k views

Rakesh K asked Nov 13, 2016

24 votes

1 answer

2565

GATE CSE 1987 | Question: 1-xvi
A critical region is One which is enclosed by a pair of $P$ and $V$ operations on semaphores. A program segment that has not been proved bug-free. A program segment that often causes unexpected system crashes. A program segment where shared resources are accessed.

A critical region isOne which is enclosed by a pair of $P$ and $V$ operations on semaphores.A program segment that has not been proved bug-free.A program segment that oft...

makhdoom ghaya

5.2k views

makhdoom ghaya asked Nov 8, 2016

3 votes

3 answers

2566

cpu scheduling
explanation please...??? and what is the difference between convoy effect and starvation?

explanation please...???and what is the difference between convoy effect and starvation?

Anmol Verma

3.1k views

Anmol Verma asked Nov 7, 2016

2 votes

2 answers

2567

Virtually indexed caches
What is virtual indexed cache? How is it different from physical indexed cache? What is virtually indexed physical tagged cache? If possible point me to proper resources.

What is virtual indexed cache? How is it different from physical indexed cache? What is virtually indexed physical tagged cache? If possible point me to proper resources....

Veerendra V

1.6k views

Veerendra V asked Nov 6, 2016

1 votes

2 answers

2568

operating system
Ans is d but according me it is wrong if we dispatch the process then it will resume the current running process..please correct me if i am wrong.

Ans is d but according me it is wrong if we dispatch the process then it will resume the current running process..please correct me if i am wrong.

Vaishali Trivedi

4.4k views

Vaishali Trivedi asked Nov 5, 2016

2 votes

1 answer

2569

difference among Critical Section ,Mutual Exclusion and Semaphore
difference in following: [i] mutual exclusion [ii] critical section [iii] semaphore

difference in following: [i] mutual exclusion [ii] critical section [iii] semaphore

LavTheRawkstar

1.7k views

LavTheRawkstar asked Nov 4, 2016

2 votes

2 answers

2570

DMA anc CPU idle time
Which of the following statements is / are true? A. In DMA approach CPU never gets idle for data transfer. B. In DMA approach, CPU becomes idle whenever DMA controller steals cycle. C. In DMA approach,DMA controller accepts a data transfer ... completing last data transfer request D. In DMA approach, CPU can proceed in parallel, only if next instructions do not need bus

Which of the following statements is / are true?A. In DMA approach CPU never gets idle for data transfer.B. In DMA approach, CPU becomes idle whenever DMA controller stea...

sh!va

2.8k views

sh!va asked Nov 4, 2016

1 votes

2 answers

2571

CAlculate the semaphore value
A counting semaphore S is created with initial value as 3. Suppose 5 processes are calling P, what will be the final value of S? A. 8 B. 0 C. -2 D. -1

A counting semaphore S is created with initial value as 3.Suppose 5 processes are calling P, what will be the final value of S?A. 8B. 0C. -2D. -1

sh!va

4.5k views

sh!va asked Nov 2, 2016

7 votes

1 answer

2572

Testbook OS Test
TLB lookup time(tn) = 20 ns , TLB hit ratio(ht) = 99% , Memory access time (ts) = 100 ns Page fault rate(hp) = 0.05% , Swap page time(in or out)(tp) = 5000,000 ns What is total access time if the page is not found in the TLB or the page table(assume that all page in main memory are dirty) ? a) 10000120 ns. b) 10000200 ns. c) 10000020 ns. d) 5000200 ns.

TLB lookup time(tn) = 20 ns , TLB hit ratio(ht) = 99% , Memory access time (ts) = 100 nsPage fault rate(hp) = 0.05% , Swap page time(in or out)(tp) = 5000,0...

Vinay Yadav

1.3k views

Vinay Yadav asked Oct 31, 2016

1 votes

1 answer

2573

Doubt in LFU Page Replacement
Q : One doubt that I feel while solving the LFU page replacement is that is it like we consider the number of times each page has been referenced till the current page reference in the reference string and then we replace that page ... or counter of each type of page references till the current page reference in the reference string?Plz someone resolve this doubt.

Q : One doubt that I feel while solving the LFU page replacement is that is it like we consider the number of times each page has been referenced till the current page re...

Habibkhan

425 views

Habibkhan asked Oct 31, 2016

1 votes

1 answer

2574

Self Doubt in Disk Scheduling
I am presenting here 2 doubts in the form of questions.Plz give proper explanation to these : Q1 : Out of the available disk scheduling algorithms , which can be considered as the best and most practical? Q2 : In CSCAN or CLOOK , we consider ... for those requests which are on the opposite side w.r.t. initial direction of head movement and hence not yet serviced ?

I am presenting here 2 doubts in the form of questions.Plz give proper explanation to these :Q1 : Out of the available disk scheduling algorithms , which can be considere...

Habibkhan

978 views

Habibkhan asked Oct 31, 2016

3 votes

3 answers

2575

Deadlock detection
Which of the following is true? S1: If there is a cycle in RAG then there will be a deadlock S2: If there is a cycle in RAG where all the resources are havinng single instance then there will be a deadlock S3: Unsafe state results in deadlock S4: Deadlock states is subset of unsafe states (A) S4 only (B) S2 & S4 only (C) S1 & S4 only (D) S1, S3 & S4 only

Which of the following is true?S1: If there is a cycle in RAG then there will be a deadlockS2: If there is a cycle in RAG where all the resources are havinng single insta...

Rakesh K

1.8k views

Rakesh K asked Oct 30, 2016

1 votes

2 answers

2576

scheduling
For calculation of turn around time = completion time -arrival time and as i know that arrival time is time at which process arrives in ready state/ready queue but in galvin book it is given thatit also includes "periods spent waiting to get into memory," i think it ... get into memory. bt it is not into( completion time -arrival time) so why we r not including that in t.a.t.

For calculation of turn around time = completion time -arrival timeand as i know that arrival time is time at which process arrives in ready state/ready queue but in ga...

saurabh rai

598 views

saurabh rai asked Oct 29, 2016

4 votes

4 answers

2577

qstn no 475 operating system NB Venkateswarulu gate csit book by tata mcgrawhill
A process can have A. Only One critical Section B.Any number of critical Section C.Os may put some restrictions on number of critical sections D.None of the above

A process can haveA. Only One critical SectionB.Any number of critical SectionC.Os may put some restrictions on number of critical sectionsD.None of the above

dasabhijeet

595 views

dasabhijeet asked Oct 27, 2016

1 votes

0 answers

2578

File system - OS : maurice j. bach
A private file system stores the directory entries the same way that the standard operating system does, except that the directory entries are 32 bytes long instead of 16. If the user mounts the private file system on a standard system, how file / dircetory access will be affected?

A private file system stores the directory entries the same way that the standard operating system does, except that the directory entries are 32 bytes long instead of 16...

sh!va

322 views

sh!va asked Oct 27, 2016

7 votes

1 answer

2579

GateForum Study Material
Given memory partitions of 100kB, 700kB, 500kB, 200kB, 100kB (in order) and requests for processes of size 112kB, 516kB, 180kB, 320kB, 190kB (in order) are placed. According to which of the following algorithms(s) all requests can be successfully placed in memory? A) First Fit B) Best Fit C) Both First Fit and Worst Fit D) Best Fit and Worst Fit

Given memory partitions of 100kB, 700kB, 500kB, 200kB, 100kB (in order) and requests for processes of size 112kB, 516kB, 180kB, 320kB, 190kB (in order) are placed. Accord...

Pratyush Madhukar

4.4k views

Pratyush Madhukar asked Oct 26, 2016

4 votes

1 answer

2580

Os+ file access

Rahul Jain25

419 views

Rahul Jain25 asked Oct 25, 2016

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