Re: math_state_restore() question

From: Hirokazu Takahashi
Date: Wed Aug 17 2005 - 03:12:34 EST


Hi,

Just take a look at __switch_to(), where __unlazy_fpu() is called.

> Hi,
>
> I have a quick question.
>
> The math_state_restore() restores the FPU/MMX/XMM states.
> However where do we save the previous task's states if it is necessary?
>
> asmlinkage void math_state_restore(struct pt_regs regs)
> {
> struct thread_info *thread = current_thread_info();
> struct task_struct *tsk = thread->task;
>
> clts(); /* Allow maths ops (or we recurse) */
> if (!tsk_used_math(tsk))
> init_fpu(tsk);
> restore_fpu(tsk);
> thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
> }
>
> Thanks in advance,
> Hiro
> --
> Hiro Yoshioka
> mailto:hyoshiok at miraclelinux.com
> -


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