Re: Kernel handling of vector registers
On Fri, 2006-02-24 at 08:35 +0100, Joerg Maier wrote:
> 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?
You can if you are in a task context (not interrupt) and if you avoid
preemption and other kind of scheduling. You need to explicitely call
enable_kernel_altivec() before anything that touches a vector register
though.
Ben.
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