I've often wondered about this oft-cited kernel behaviour too, in my
naivety. I understand
that this must be on a per-arch basis, but does this mean that the kernel
doesn't police FP
access at _all_ (perhaps this is what Mohit means too)? Does code like X for
example have to access it directly, or does it just use the GPU? What about
other user-space code - does it
have a separate library and do its own security? Video drivers?
Sorry if these are basic questions, I grepped for float in the kernel but
as-yet the associated
code looks really arcane to me - if anyone could answer any of these
questions generally
(if that's possible) that would be very helpful with visualizing the
mechanism.
Maybe I'm looking in the wrong place.
When I started looking at the kernel I imagined this small, neat, concise
piece of highly
efficient code so I wasn't surprised there was no float (don't laugh - how
one learns :-/ ) ...
I suppose any float per-arch 'hacks' (to get a larger word size) would not
be worth
the overhead of the mode switch and extra code?
Thanks
Julie
