On Mon, Dec 14, 2009 at 07:44:31AM -0500, Ted Unangst wrote:
> On Mon, Dec 14, 2009 at 3:58 AM, Otto Moerbeek <[email protected]> wrote:
> >> apart from the random page addresses obtained form mmap(2) malloc(3)
> >> itself also randomizes cache en chunk operations. It uses a nibble of
> >> randomness per call, so optimize that to not waste half the random
> >> bits.
> >>
> >> Please test, should be a bit faster.
>
> I don't really like this. It looks complicated (hard to judge). arc4
> is fast enough I don't think we need to worry about conserving bits,
> and I'd be surprised if it actually were faster considering how much
> work you're doing per nibble compared to the work to just run arc4.
> However fast it may be, I feel much safer with the current code.
Every call to arc4random_buf() causes a getpid() call, which is a
syscall with all the overhead. This saves half of those.
-Otto
