Re: Kernel handling of vector registers
i was wrong, i misread the first question, and he told me, GMP is in
userspace. by kernel "handling of the SIMD regs" he meant the switch from
one userspace task to another, i think.
what do you mean by "in a limited context"? Can you use SIMD in kernel
code regs if you avoid preemtion?
joerg
On Fr, 24.02.2006, 01:24, Benjamin Herrenschmidt sagte:
> On Thu, 2006-02-23 at 17:17 +0100, Joerg Maier wrote:
>> Hi,
>>
>> you cannot use SIMD registers in kernel as far as i know. The kernel
>> does
>> not save these registers when changing userspace/kernel mode (i think
>> for
>> performance reason) so these registers have to stay untouched when you
>> are
>> in kernel mode.
>
> ahhh ... I assumed he was doing userland... if he's doing kernel, he can
> still but in a very limited context, like the RAID6 does, though I
> wouldn't recommend it unless there is a very very very good reason to do
> so.
>
> Ben.
>
>
>
>
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