A short thread on the lkml discussed the lack of a
memzero function in the Linux kernel. Cyrill Gorcunov asked, "could anyone tell me why there is no official
memzero function (or macros) in the kernel?" Arjan van de Ven explained, "it doesn't add value....
memset with a constant 0 is just as fast (since the compiler knows it's 0) than any wrapper around it, and the syntax around it is otherwise the same." Linux creator Linus Torvalds went on to explain:
"The reason we have '
clear_page()' is not because the value we're writing is constant - that doesn't really help/change anything at all. We could have had a '
fill_page()' that sets the value to any random byte, it's just that zero is the only value that we really care about.
"So the reason we have '
clear_page()' is because the *size* and *alignment* is constant and known at compile time, and unlike the value you write, that actually matters. So '
memzero()' would never really make sense as anything but a syntactic wrapper around '