Linux's reasoning is documented here [0]. The justification for not using it for memory-mapped IO is that you are supposed to use accessor functions. Volotile

Linux's reasoning is documented here [0]. The justification for not using it for memory-mapped IO is that you are supposed to use accessor functions. Volotile still has uses for implementing those accesor functions (with care taken for the other concerns; and, by there nature, these functions are architecture dependent anyway), or when you are not using a kernel. [0] https://www.kernel.org/doc/Documentation/volatile-considered-harmful.txt https://www.kernel.org/doc/Documentation/volatile-considered...