Re: [PATCH] Re: SSE related security hole

Andrea Arcangeli
2002-04-21T02:10:31Z

On Sat, Apr 20, 2002 at 03:43:17PM -0700, H. Peter Anvin wrote:
> Andrea Arcangeli wrote:
> >
> >As said in an earlier email it is a matter of memory bandwith, 59 bytes
> >of icache and zero data, against 7 bytes of icache and 512bytes of data.
> >the 512bytes of data are visibly slower, period. Saving mem bandwith is
> >much more important than reducing the number of instructions, even more
> >on SMP!
> >
>
> It's not 512 bytes of data -- only the part that's actually used is
> accessed.

On current x86 yes (so far), but the x86-64 the whole 512bytes will have
to be read from ram instead.

Andrea