[ Please CC replies to me - thanks. ]
I have a question with regards to this code:
/*
* FPU lazy state save handling.
*/
static inline void __save_init_fpu( struct task_struct *tsk )
{
if ( cpu_has_fxsr ) {
asm volatile( "fxsave %0 ; fnclex"
: "=m" (tsk->thread.i387.fxsave) );
} else {
asm volatile( "fnsave %0 ; fwait"
: "=m" (tsk->thread.i387.fsave) );
}
tsk->flags &= ~PF_USEDFPU;
}
I'm curious why Linux does the 'fwait', whereas I don't see that
happening in other OS's, like FreeBSD and eCos. I'm not that
experienced with x86 asm, so I'm trying to understand the difference
in usage between them.
Thankyou for your time,
--
David N. Welton
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