Re: memset as memzero

Linus Torvalds
2007-09-22T18:59:58Z

On Sat, 22 Sep 2007, Arjan van de Ven wrote:
>
> 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.

Indeed.

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 "memset(x,0,size)".

Linus