A 32-bit processor can address a maximum of 4GB of memory. Linux kernels split the 4GB address space between user processes and the kernel; under the most common configuration, the first 3GB of the 32-bit range are given over to user space, and the kernel gets the final 1GB starting at 0xc0000000.

What is kernel memory in Linux?

Also, it is the kernel that maintains the page table for all the pages that represent actual memory in RAM. … On x86 system the total physical RAM addressable by CPU is 4GB ( leave PAE(Physical Address Extension out of it for now ).

How much memory Linux is using?

free Command

free is the most commonly used command for checking the memory usage of a Linux system. It displays information about the total, used, and free memory. Here’s what each column mean: total – The total amount of memory that can be used by the applications.