📝 Approaches to Multiple Processor Scheduling (46 MCQs)

📖 Explanation: In asymmetric multiprocessing, the master server is a single processor that handles all scheduling decisions, I/O processing, and other system activities. This centralizes control to simplify system management and reduce data sharing conflicts.

📖 Explanation: In asymmetric multiprocessing, the other processors (non-master) execute only user code. The master server handles all system activities, including scheduling and I/O, while the remaining processors focus on executing user applications.

📖 Explanation: Asymmetric multiprocessing is simple because only one processor (the master server) accesses the system data structures. This reduces the need for complex data sharing and synchronization mechanisms that would be required if multiple processors accessed the same data.

📖 Explanation: Symmetric multiprocessing (SMP) is an approach where each processor is self-scheduling. All processors are equal and can execute both user and system code, with each processor independently examining the ready queue and selecting processes to execute.

📖 Explanation: In SMP systems, ready processes may be placed in a common ready queue shared by all processors, or each processor may have its own private queue of ready processes. Both configurations are possible depending on the system design.

📖 Explanation: A key challenge in SMP scheduling is that multiple processors may try to access and update common data structures simultaneously. This requires careful programming to ensure mutual exclusion and prevent data corruption.

📖 Explanation: Virtually all modern operating systems support SMP, including Windows, Linux, and Mac OS X. This widespread support reflects the prevalence of multi-core processors and the need for efficient scheduling across multiple CPUs.

📖 Explanation: In asymmetric multiprocessing, the master server handles all scheduling decisions, I/O processing, and other system activities. This centralized control simplifies the system by limiting which processor accesses system data structures.

📖 Explanation: SMP stands for Symmetric Multiprocessing. This approach treats all processors as equal and self-scheduling, with each processor independently scheduling processes from the ready queue.

📖 Explanation: In SMP, each processor independently examines the ready queue and selects a process to execute. This self-scheduling approach allows all processors to participate in scheduling decisions without central coordination.

📖 Explanation: A common ready queue in SMP is a single queue that is shared by all processors. All processors examine this same queue to select processes for execution, requiring careful synchronization to prevent conflicts.

📖 Explanation: A private ready queue in SMP is a queue that belongs to each individual processor. Each processor has its own ready queue and selects processes from its own queue without needing to access a shared queue.

📖 Explanation: The primary advantage of asymmetric multiprocessing is simplicity. Since only one processor (the master server) accesses system data structures, there is reduced need for complex data sharing mechanisms and synchronization, making the system easier to implement and manage.

📖 Explanation: The primary advantage of symmetric multiprocessing is better load balancing and scalability. All processors can handle system tasks, allowing workloads to be distributed more evenly across processors and enabling the system to scale with additional processors.

📖 Explanation: When multiple processors access a common ready queue, careful programming is needed to ensure that two separate processors do not choose to schedule the same process. This requires proper synchronization mechanisms like locks or atomic operations.

📖 Explanation: When multiple processors access a common ready queue, processes could be lost from the queue if synchronization is not handled correctly. This could happen if a process is removed from the queue by one processor while another processor is also trying to access it.

📖 Explanation: The need for data sharing is reduced in asymmetric multiprocessing because only one processor (the master server) accesses system data structures. Other processors execute only user code and do not need to access shared system data, simplifying synchronization.

📖 Explanation: Virtually all modern operating systems support SMP due to the prevalence of multi-core processors. SMP allows workloads to be distributed across multiple cores, improving performance and scalability in modern systems.

📖 Explanation: In SMP, each processor has its own scheduler (or the scheduling function runs on each processor). Each processor independently examines the ready queue and selects a process to execute, making scheduling a distributed activity.

📖 Explanation: In asymmetric multiprocessing, processors have different roles (master server handles system activities, others handle user code). In symmetric multiprocessing, all processors have equal roles and can handle both system and user code.

📖 Explanation: Asymmetric multiprocessing reduces the need for data sharing because only the master server accesses system data structures. Other processors only execute user code and do not need to access shared system data, minimizing synchronization requirements.

📖 Explanation: The master server in asymmetric multiprocessing handles all scheduling decisions, I/O processing, and other system activities. This centralized approach simplifies the system by having a single processor responsible for all system-level operations.

📖 Explanation: A potential disadvantage of using a common ready queue in SMP is the need for synchronization to prevent conflicts. Multiple processors accessing the same queue require locks or atomic operations, which can create overhead and reduce performance.

📖 Explanation: Private ready queues reduce the need for synchronization because each processor only accesses its own queue. This eliminates the contention that occurs with a common ready queue, potentially improving performance in some configurations.

📖 Explanation: Asymmetric multiprocessing is the term for systems where one processor (the master server) handles all system activities, including scheduling and I/O processing, while other processors execute only user code.

📖 Explanation: Symmetric multiprocessing is the term for systems where all processors are self-scheduling. Each processor independently examines the ready queue and selects processes to execute, making all processors equal in terms of scheduling responsibility.

📖 Explanation: The scheduler must be programmed carefully in SMP systems to ensure that two separate processors do not choose to schedule the same process and that processes are not lost from the queue. This requires proper synchronization and careful management of shared data structures.

📖 Explanation: If synchronization is not handled correctly in a common ready queue, processes may be duplicated (two processors selecting the same process) or lost from the queue entirely. This can lead to incorrect execution or resource starvation, requiring careful programming to avoid.

📖 Explanation: The master server approach in asymmetric multiprocessing uses a single processor to handle all scheduling decisions, I/O processing, and other system activities. This centralizes system control and reduces the complexity of data sharing among processors.

📖 Explanation: In asymmetric multiprocessing, other processors do not need to access system data structures because they execute only user code. System activities like scheduling and I/O are handled exclusively by the master server, so other processors only interact with user-level data.

📖 Explanation: The trade-off is between simplicity (asymmetric) and scalability/load balancing (symmetric). Asymmetric is simpler to implement but may not scale well, while symmetric offers better scalability and load distribution but requires more complex synchronization.

📖 Explanation: A system designer might choose asymmetric multiprocessing to reduce complexity and synchronization needs. With only one processor accessing system data structures, the system is simpler to implement and debug, though it may not scale as well as SMP.

📖 Explanation: A system designer might choose symmetric multiprocessing to achieve better load balancing and scalability. All processors can handle system tasks, allowing workloads to be distributed evenly and enabling the system to scale with additional processors.

📖 Explanation: For private ready queues to work effectively, the queues must be balanced. If one processor has many processes and another has few, load imbalance can occur, reducing overall system utilization and performance.

📖 Explanation: Asymmetric multiprocessing uses a master-slave architecture where one processor acts as the master (handling system activities) and others act as slaves (executing user code). This is a key characteristic of asymmetric multiprocessing.

📖 Explanation: When all processors use a common ready queue in SMP, processors need to synchronize access to the queue. This typically requires locking mechanisms or atomic operations to prevent conflicts and ensure correct scheduling behavior.

📖 Explanation: Improper synchronization in SMP scheduling can lead to processes being lost or duplicated. A process might be removed from the queue by one processor while another processor is also trying to schedule it, or a process might be left unaccounted for if synchronization fails.

📖 Explanation: Most modern operating systems use symmetric multiprocessing (SMP). This approach is better suited for modern multi-core processors and provides better scalability and load balancing than asymmetric multiprocessing.

📖 Explanation: In common ready queues, all processors share a single queue. In private ready queues, each processor has its own queue. This difference affects synchronization requirements, load balancing, and overall system performance.

📖 Explanation: Modern operating systems support SMP to effectively utilize multiple processor cores. SMP allows workloads to be distributed across cores, improving performance and providing better resource utilization in multi-core systems.

📖 Explanation: SMP is designed for multi-core and multi-processor systems. It provides the framework for distributing workloads across multiple cores, which is essential for leveraging the performance capabilities of modern multi-core processors.

📖 Explanation: If the master server fails in asymmetric multiprocessing, the system may crash or stop functioning properly because the master handles all system activities. Other processors only execute user code and cannot take over system responsibilities without additional mechanisms.

📖 Explanation: The load balancing challenge in private ready queues is ensuring that processes are distributed equally among the queues. If one processor's queue is overloaded while another is empty, CPU resources are wasted and performance degrades.

📖 Explanation: The fundamental trade-off is between simple implementation (asymmetric) and complex but more scalable/balanced implementation (symmetric). Asymmetric simplifies system design but may not scale well, while symmetric offers better performance at the cost of implementation complexity.

📖 Explanation: Asymmetric multiprocessing has reduced data sharing needs because only the master server accesses system data structures. Other processors execute only user code and do not need to access or modify shared system data, significantly reducing the need for synchronization.

📖 Explanation: The primary challenge in implementing SMP with a common ready queue is synchronizing access to the queue. Multiple processors must be prevented from simultaneously modifying the queue to avoid conflicts, requiring locking mechanisms or atomic operations.