&gt; C doesn&#x27;t hide anything from you.<p>Yes, it does.<p>C hides cache, SIMD, registers, the stack (no multiple return values for you!), the details of the heap (malloc() either succeeds or fails, and you can&#x27;t know what it&#x27;s going to do until you call it), SMP, instruction-level parallelism, and the details of atomicity, all of which are relevant to OS programming.<p>C is a nice language. Don&#x27;t pretend it&#x27;s how the hardware really works.