search
person

1 Answer

The scheduler is very important in Real-Time Operating System (RTOS). Selection of tasks for execution is provided by the scheduler. Which task to execute when it is provided by the scheduler.There are different types of the scheduling algorithm. Preemptive scheduling, Round-robin scheduling, cooperative scheduling are the types of scheduling algorithms. Mostly developer uses these algorithms but if needed Developer can create own custom scheduling algorithm.


Comparision between preemptive and non-preemptive scheduling:


If the process is running and a new process with high priority come to the processor the preemptive scheduling force the running process to remove and run the process with high priority. This is not the case in non-preemptive scheduling, in non-preemptive scheduling the processor does not remove the process until it completes the process.

In case of preemptive scheduling, the operating system has control to the processor in running state of the process. But, in case of non-preemptive scheduling once the process in the processor is in running state the operating system has no control over the processor.

"First come first served" is the type of non-preemptive scheduling. "Round-robin scheduling" is the type of preemptive scheduling.

Preemptive scheduling is not simple. Non-preemptive scheduling is simple.

Preemptive scheduling is flexible while non-preemptive scheduling is rigid.

thumb_up_alt 0 like thumb_down_alt 0 dislike

Related questions

Description : what are the significance of kernel in RTOS ?

Answer : In every RTOS there is the kernel. The kernel is the core supervisory software. The kernel provides minimal logic. Scheduling is also provided by the kernel. The resource- ... device managment service.RTOS kernel has interrupt management service.RTOS kernel has memory management service.

Description : Consider three CPU intensive processes P1, P2, P3 which require 20, 10 and 30 units of time, arrive at times 1, 3 and 7 respectively. Suppose operating system is implementing Shortest Remaining Time first (preemptive scheduling) ... end of Ready queue are not counted). (A) 3 (B) 2 (C) 4 (D) 5

Answer : (A) 3

Description : Linux operating system uses (A) Affinity Scheduling (B) Fair Preemptive Scheduling (C) Hand Shaking (D) Highest Penalty Ratio Next

Answer : (B) Fair Preemptive Scheduling Explanation: Linux uses two process-scheduling algorithms: 1. A time-sharing algorithm for fair preemptive scheduling between multiple processes 2. A real-time algorithm for tasks where absolute priorities are more important than fairness

Description : A scheduling Algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero (lowest priority). The scheduler re-evaluates the process priority for every 'T' time ... (A) Priority scheduling (B) Round Robin Scheduling (C) Shortest Job First (D) FCFS

Answer : (B) Round Robin Scheduling

Description : Which scheduling service is used to handle traffic with different priorities? (1) Traffic management (2) QoS traffic scheduling (3) QoS Scheduler (4) Qos Manager

Answer : QoS traffic scheduling

Answer : Some embedded systems have Real-Time Operating Systems (RTOS) and some of them not. Real-Time Operating Systems is a platform for building applications for embedded systems, Smaller Software ... they just have application code without RTOS. Every Real-Time Operating Systems have the kernel.

Description : In ancient education system, teachers applied some psychological principles in education especially to young child from pre-school age to adolescence. They recognize the role of Options: A) Gurukul Type Of ... System Of Schooling C) Sense And Perception In Teaching And Learning D) All Of These

Answer : C) Sense And Perception In Teaching And Learning 

Description : Which of the following disk scheduling techniques has a drawback of starvation? (A) SCAN (B) SSTF (C) FCFS (D) LIFO 

Answer : Which of the following disk scheduling techniques has a drawback of starvation? (A) SCAN (B) SSTF (C) FCFS (D) LIFO 

Answer : There are two main types of task scheduling algorithm in Real-Time Operating Systems (RTOS).1. Rate Monotonic Scheduling (RMS)2. Earliest-Deadline-First (EDF)Rate Monotonic Scheduling ( ... shortest period process and so on.Rate Monotonic Scheduing do not support non-periodic processees.

Description : What is the real time scheduling?

Answer : Hard real-time and soft real-time are the types of real time scheduling. Real time 

Description : Effective communication pre-supposes (A) Non-alignment (B) Domination (C) Passivity (D) Understanding

Answer : (D) Understanding

Description : Compare the annual growth rate of  1.IC capacity 2.Designer productivity.

Answer : Compare the annual growth rate of 1.IC capacity2.Designer productivity.

Description : Compare binary ASK, FSK &PSK modulation techniques 

Answer : Sr. No Parameter Binary ASK Binary FSK Binary PSK 1 Variable Characteristic Amplitude Frequency Phase 2 Maximum bandwidth(Hz) 2fb 5 fb /3 2fb 3 ... 1200 bits/sec Suitable for high bit rates 8 Detection method Envelope Envelope Coherent

Description : Compare: 1. Active and passive network 2. Linear and non-linear network

Answer : 1. Active network and passive network. Sr.No Active network Passive network 1 If a network consists of an energy source, then it is called as an active network. If ... only to the linear networks.  The superposition theorem also is not applicable to the nonlinear networks.

Description : Compare resonant and non-resonant antennas.

Answer : Distinguish between resonant and non-resonant antennas.

Description : List non contact type transducer and compare them on the basis of any two factors.

Answer : Magnetic pick-up Photoelectric This tachometer generator consists of a metallic tooth rotor mounted on the shaft whose speed is to be measured. This method of measuring speed of rotation ... by an electronic counter which can be directly calibrated in terms of speed in rpm.

Description : Compare contact type and non-contact type speed measurement method.

Answer : Contact type method Non contact type method Physical contact between meter and shaft  No Physical contact between meterand shaft Consists of moving parts Does not consist of moving parts ... is less  Ex.AC / DC tachometer Ex. Rotary Encoder, Photo electric tachometer

Description : Explain pre-emphasis and de-emphasis concept in FM.

Answer : Pre-emphasis:- In an FM system the higher frequencies contribute more to the noise than the lower frequencies. Because of this all FM systems adopt a system of pre-emphasis where the higher frequencies are ... at receiver to improve the noise immunity Pre-emphasis/ De-emphasis graph:

Description : Some of the criteria for calculation of priority of a process are: a. Processor utilization by an individual process. b. Weight assigned to a user or group of users. c. Processor utilization by a user or group of processes. In fair share ... (a) and (c) (3) (a), (b) and (c) (4) only (b) and (c)

Answer : (3) (a), (b) and (c)

Description : In computer processing, ______ selects processes from the pool and loads them into memory for execution. (1) Job Scheduler (2) Resource Scheduler (3) CPU Scheduler (4) Process Scheduler

Answer : Job Scheduler

Description : State two examples of RTOS.

Answer : 1. LynxOS. 2. OSE. 3. QNX. 4. RTLinux. 5. VxWorks. 6. Windows CE.

Description : State and describe types of scheduler.

Answer : There are three types of scheduler: Long term scheduler Short term scheduler Medium term scheduler 1. Long term scheduler: It selects programs from job pool and loads them into the ... scheduler works in close communication with long term scheduler for loading process into the main memory. 

Description : Explain any four scheduling criteria.

Answer : 1. CPU utilization: In multiprogramming the main objective is to keep CPU as busy as possible. CPU utilization can range from 0 to 100 percent. 2.Throughput: It is the number of processes ... fairly early and can continue computing new results while previous results are being output to the user.

Description : Explain four basic principles of software project scheduling.

Answer : Basic principles software project scheduling:  Compartmentalization: The project must be compartmentalized into a number of manageable activities and tasks. To accomplish compartmentalization, both the product and ... or part of a work product - Work products are often combined in deliverables 

Description : Explain event scheduling with suitable example.

Answer : Event scheduling: The assignment to signal x does not happen instantly. Each of the values assigned to x contain an afterclause. The mechanism for delaying the new value is called scheduling an event. By ... value. Event is nothing but change on target signal which is to be updated. Example: X

Description : Explain Pre- monsoon inspection of bridge.

Answer : The Pre- Monsoon inspection shall cover the following points a) Any sign of settlement of Foundation. b) Check the condition of reinforcement. c) Any sign of development of cracks in concrete abutments ... of steel works of girder. j) Obstruction of water way. k) Inspection of drainage system.

Description : CPU Scheduler is also known as _____ . (1) Job Scheduler (2) Resource Scheduler (3) Short-term Scheduler (4) Process Scheduler

Answer :  Short-term Scheduler

Description : Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).

Answer : (i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.

Description : State and explain different signal conditioning techniques used in DAS. 

Answer : Signal conditioning is the technique of making a signal from a sensor or transducer suitable for processing by data acquisition system. Types of Signal Conditioning Amplification: Amplification increases a ... glass electrodes used to measure pH, or gas concentration probes, are of this type. 

Description : Explain fast frequency hopping techniques with suitable waveforms. State its advantage and disadvantages. 

Answer : In Fast Frequency hopping multiple frequencies or hops are used to transmit one symbol. The hop rate is higher than symbol rate but chip rate is equal to hop rate For each symbol ... at receiver 3. Complex and expensive digital frequency synthesizers are required 4. Data rates are low

Description : Explain the ultrasonic pulse velocity test and techniques of measuring pulse velocity through concrete.

Answer : Procedure: i. Ultrasonic pulse velocity method consists of measuring the time travel of an ultrasonic pulse passing through the concrete to be tested. ii. The pulse generated circuit consists of ... The transmitting and receiving transducers are placed on same surfaces of the concrete slab

Description : Explain the “mitigation of power theft” and “faulty meter replacement” for energy conservation techniques to reduce commercial losses. 

Answer : Energy conservation techniques to reduce commercial losses:  1. Mitigation of Power Theft: Power theft being the most important issue which all of the service providing utilities ... agricultural sector. Prepaid meters may prove effective measures against unauthorized abstraction of energy. 

Description : Explain different gate drives techniques with base circuits and key features.

Description : Explain placement, routing, and sizing.

Answer : Placement: The task of placing and orienting every transistor somewhere on IC. Routing: The task of running wires between the transistors without inserting other wires or transistors. ... wires and transistor provide better performance but consume more power and require more silicon area.

Description : Explain the advantages and disadvantages of using memory I/O and standard I/O.

Answer : Memory mapped I/O and standard I/O are the two methods for communicating microprocessor with peripherals. Processor talks to both memory and peripheral using the same bus.Two ways to talk to a peripheral. ... of standard I/O is no loss of memory addresses to the use as I/O addresses.

Description : Explain parallel and wireless protocols.

Answer : Parallel protocols: PCI bus (Peripheral Components Interconnect): PCI stands for Peripheral Components Interconnect. PCI bus is used as a communication line to transmit signals and data ... provide the basis for wireless network products using the Wi-Fi brand.

Description : Explain memory write ability and storage permanence with suitable diagram.

Answer : Write ability and storage permanence of memories: Write ability is the manner and speed at which memory can be written. Storage permanence is the ability of memory to hold stored bits ... Holds bits after power is no longer supplied. High end and middle range of storage permanence.

Description : Explain FSM and concurrent process with example.

Answer : Finite State Machine (FSM): Finite state machine is a machine which have a transition from state to state. The system have some number of states and at a time the system can ... Y seconds. In sequential execution, the processor executes single task which causes poor processor utilization.

Description : What is watchdog timer ? Explain the implementation of time out for ATM with block diagram and program.

Answer : A special type of timer is a watchdog timer, which will reset the system after a predefined timeout. Watchdog timer reset timer every X time unit, else timer generates a signal ... be loaded into timereg. This is to prevent erroneous software from unintentionally resetting the watchdog timer.

Answer : Shared memory :For sharing of data faster and communication between programs, we use shared memory. Shared memory can be used with multiprocessors and single processors. Means Program ... No resource preemption4. Circular waitIf the four conditions occur simultaneously then the deadlock occurs.

Description : List and explain the various functions supported by Linux/RTLinux.

Answer : Various functions of RTLinux is as follows: Interrupt handling functions

Description : Explain the different recording techniques used in method study. Also outline process chart for checking diameter of 50mm of shaft.

Answer : Different recording techniques used in method study: Process charts are used to record the data systematically so that none of the information needed for study and analysis is missed. A. Chart indicating ... area. However, there is no indication of the direction or speed of motion.

Description : Explain interpolation techniques in curve generation.

Answer : Specify a spline curve by giving a set of coordinate positions, called control points, which indicates the general shape of the curve These, control points are then fitted with piecewise continuous ... a design application. Straight lines connect the control -point positions above the surface.

Description : Explain the following energy conservation techniques: (i) By reducing I2R losses in Trans. system (ii) By optimizing distribution voltage.

Answer : i) By reducing I2R losses in Trans:  1. Opting for low resistance All Aluminum Alloy conductors (AAAC) in place of conventional aluminum cored steel reinforced (ACSR) lines. 2. ... line power losses. Thus maintaining the voltages at the specified levels leads to energy savings/conservation.

Description : Explain any two energy conservation techniques in fan.

Answer : Following are energy conservation techniques in Fans : 1) Use the electronic regulators instead of conventional regulator: Function of regulator is to control the speed of the fan. The conventional regulators ... 't forget to properly maintain your electric fan and keep it in good working order. 

Description : List the different techniques used for signal conditioning in DAS. Explain in brief Any one signal conditioning technique.

Answer : Types of Signal Conditioning techniques in DAS: 1) Attenuation 2) Amplification 3) Linearization 4) Filtering 5) Ratiometric conversion 6) Logarithmic conversion  Attenuation: An ... in medical investigatory circuits, photo detectors, ionizing radiation detectors and ultrasound receivers etc.

Description : Explain the various steps involved in designing a custom single-purpose processor.

Answer : A single purpose processor is a digital circuit designed to execute exactly one program. It is also known as co-processor, accelerator or peripheral. It contains only ... for small quantities. Performance may not match general-purpose processors for same applications.

Description : Explain data transfer mechanism in I2C protocol. Compare it with CAN and USB protocol based on bit rate and area of applications.

Answer : I2C (Inter-Integrated Circuit): I2C stands for Inter-Integrated Circuit. I2C is a serial protocol. It was developed by Philips Semiconductor. I2C bus have two communication lines. One is serial data ( ... Mbps this is used for lower speed devices. Using USB we can connect upto 127 devices.

← Prev Question Next Question →
editAsk a Question
...