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What is the best definition of an address space?
An address space is a range of valid addresses in memory that are available for a program or process. That is, it is the memory that a program or process can access. The memory can be either physical or virtual and is used for executing instructions and storing data.
What is an address space in a computer?
A computer’s address space is the total amount of memory that can be addressed by the computer. The term may refer to the physical memory (RAM chips) or virtual memory (disk/SSD). For example, a 32-bit computer can address 4GB of physical memory and as much as 64TB of virtual memory.
What is user space in OS?
In a computer operating system, user space is the portion of memory containing unprivileged processes run by a user. It is strictly separated from kernel space, the portion of memory where privileged operating system kernel processes are executed.
Why do we need an address space in a computer?
Because it maps all of the available addresses, an address space includes system code and data as well as user code and data. Thus, not all of the mapped addresses are available for user code and data. The ability of many users to share the same resources implies the need to protect users from one another and to protect the operating system itself.
How big is the address space in Linux?
For example, on a 32-bit x86 machine running Linux, the kernel resides in the 0xc00000000–0xffffffff range (the “top” gigabyte of virtual memory), whereas each process is free to use all the addresses beneath this range (the “lower” 3GB of virtual memory).
Can a data address space be the same?
Some elements of a data address space may be the same, but if any element in the address is different, addresses in said space will reference different entities.
How is the address space managed in a process?
The address space usable by the process is managed by a high level mm_structwhich is roughly analogous to the vmspacestruct in BSD [McK96]. Each address space consists of a number of page-aligned regions of memory that are in use.