Re: Kernel oops with 2.6.26, padlock and ipsec: probably problemwith fpu state changes

[H. Peter Anvin]

Ingo Molnar wrote:
> * Suresh Siddha <suresh.b.siddha@xxxxxxxxx> wrote:
>
> > Reported-and-bisected-by: Wolfgang Walter <wolfgang.walter@xxxxxxx>
> > Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
>
> no fundamental objection to the x86 bits.
>
> shouldnt this:
>
> +       if (!in_interrupt())
> +               return 0;
>
> just be eliminated and the cr0/TS save/restore be made unconditional?  
> irq-assymetric APIs are not nice in general.
>
> Reading/setting cr0 isnt _that_ slow. (or if it is, by how much does it 
> slow things down, exactly?)

Setting it is relatively slow.  I think that's part of the reason for 
special instructions to muck with the TS flag.

Reading it might be slow on obsolete processors.

	-hpa
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