Re: [patch 2.6.13-rc3a] i386: inline restore_fpu

[Linus Torvalds <torvalds@osdl.org>]

On Sat, 23 Jul 2005, Chuck Ebbert wrote:
> 
>    Probably a very minor point, but shouldn't it be
> 
>                         "m" ((tsk)->thread.i387.fxsave))
> 
> because that's the largest possible operand that could end up being read?

Yes, I ended up fixing that already (along with handling the fxsave case 
too).

>   Is that function called __save_init_fpu because it saves and then
> initializes the fpu?  Unlike fsave, fxsave does not init the fpu after
> it saves the state; to make the behavior match it should be "fxsave ; fninit"

The "init" part is really just "reset_exceptions" - we don't care about
the rest of the state, and the naming is historical (ie it's really called
"init" because "fnsave" does the reset by re-initializing everything, ie 
there's an implied "fninit").

So for the fxsave path, we just use fnclex, since that's faster than a
full fninit.

			Linus
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