What is address space in Linux?
The address space of a process consists of all linear addresses that the process is allowed to use. Each process sees a different set of linear addresses; the address used by one process bears no relation to the address used by another.
Is the virtual address space by the Linux address space?
The virtual address space of any Linux process is divided into two subspaces: kernel space and user space.
What is Vmalloc memory?
Vmalloc() is used to allocate memory from the kernel. The memory allocated is virtually contiguous but not physically contiguous. This API works in the similar manner as the user level malloc() works.It means vmalloc ensures memory is allocated from vitual address space.In vmalloc there is no option to define flag.
What is Vmalloc area?
The functions vmalloc(), vmalloc_dma() and vmalloc_32() are provided to allocate a memory area that is contiguous in virtual address space. They all take a single parameter size which is rounded up to the next page alignment. They all return a linear address for the new allocated area.
What is memory address space?
Address space is the amount of memory allocated for all possible addresses for a computational entity — for example, a device, a file, a server or a networked computer. The system provides each device and process address space that holds a specific portion of the processor’s address space.
What is the size of the virtual address space?
4 gigabytes
The virtual address space for a user-mode process is called user space. In 32-bit Windows, the total available virtual address space is 2^32 bytes (4 gigabytes). Usually the lower 2 gigabytes are used for user space, and the upper 2 gigabytes are used for system space.
Where is virtual address space stored?
secondary storage
The virtual address space is kept in secondary storage (disk). The virtual part of virtual memory means that the operating system maintains an image of the address space in secondary storage. Because an image of the address space is kept in secondary storage, it can be larger than the physical memory.
What is Kzalloc in Linux?
kzalloc — allocate memory. The memory is set to zero. kzalloc_node — allocate zeroed memory from a particular memory node.
What is Ioremap in Linux?
ioremap() function is used to map the physical addres of an I/O device to the kernel virtual address. Kernel creates a page table i.e mapping of virtual address to the physical address requested. When we do iounmap() this mapping is destroyed.
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