What is MMAP in Linux?

In computing, mmap(2) is a POSIX-compliant Unix system call that maps files or devices into memory. It is a method of memory-mapped file I/O. … In Linux, macOS and the BSDs, mmap can create several types of mappings.

How does MMAP work in Linux?

mmap works by manipulating your process’s page table, a data structure your CPU uses to map address spaces. The CPU will translate “virtual” addresses to “physical” ones, and does so according to the page table set up by your kernel. When you access the mapped memory for the first time, your CPU generates a page fault.