GIOS P2L4 - Part 1

What are the two levels at which threads can be supported?

• Kernel level and user level

• Process level and system level

• Hardware level and software level

• Single level and multiple levels

What does the user level thread library provide?

• Management and support for threads

• Virtual address mapping

• Kernel level scheduling mechanisms

• Process control block

How can user level threads be mapped onto kernel level threads?

• 1:1, many:1, and many:many patterns

• Single CPU and multiple CPUs

• User level and kernel level

• Process control block and thread data structure

What does the user level thread data structure contain?

• Thread ids, thread registers, and thread stacks

• Virtual address mapping, stack, and registers

• Process control block, stack, and registers

• Kernel level threads and CPUs

Why is the process control block split into smaller structures for multiple kernel level threads?

• To avoid replicating the entire process control block

• To simplify thread scheduling and synchronization

• To support user level thread libraries

• To maintain relationships among data structures

What is the purpose of the red zone in the thread data structure?

• To detect errors caused by thread boundary overruns

• To represent the virtual CPUs for user level threads

• To provide compact representation of threads in memory

• To separate information about each thread

What does the lightweight process (LWP) data structure contain?

• User level registers, system call arguments, and signal masks

• Kernel level registers, stack pointer, and scheduling info

• Virtual address space, user credentials, and signal handlers

• Execution context, registers, and thread local storage

What information is contained in the kernel level thread data structure?

• Kernel-level registers, stack pointer, and scheduling info

• User level registers, system call arguments, and resource usage info

• Virtual address mapping, stack, and registers

• Thread ids, thread registers, and thread stacks

What does the CPU data structure contain?

• Current thread, list of kernel level threads, and dispatching & interrupt handling info

• User level registers, system call arguments, and signal masks

• Virtual address space, user credentials, and signal handlers

• Execution context, registers, and thread local storage

What is the purpose of the process data structure?

• To store information about the user and virtual address mapping

• To maintain relationships between user level threads and process control blocks

• To represent the virtual CPUs for user level threads

• To provide compact representation of threads in memory