How much memory does a call to 'malloc' allocates? – Daniel Lemire's blog

In C programming, the malloc function is used to allocate memory on the heap. When calling malloc(1) to allocate just one byte, modern systems typically allocate virtual memory, which may or may not correspond to physical memory. There is a fixed overhead per allocation, usually around 8 bytes of metadata, which the system uses to track memory allocations. Due to alignment and minimum size requirements, requesting 1 byte may actually result in receiving between 16 to 24 bytes of usable memory. It is advised to avoid allocating very small blocks of memory and not to optimize allocation size down to a few bytes since it gets rounded up anyway. The realloc function can be used to extend memory allocations efficiently. Different systems handle memory allocation differently, so it's best to focus on the broader concepts rather than making generalizations about specific systems like Linux or macOS. Overall, understanding how malloc works and its implications on memory usage is crucial for efficient memory management in programming.