Re: [PATCH RT v2] arm64: fpsimd: use a local_lock() in addition to local_bh_disable()

[Sebastian Andrzej Siewior]

On 2018-07-18 11:12:10 [+0200], To Dave Martin wrote:
> > > -	if (may_use_simd()) {
> > > +	if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE) && may_use_simd()) {
> > 
> > I suspect this is wrong -- see comments on the commit message.

I'm sorry, I pressed send too early, I was aiming for the draft folder.
So yes, based on that EFI that might be interruptible, let me try to
look at the initial issue again and maybe I get another idea how to deal
with this.
One question: If EFI is interruptible that means, we call into EFI - how
do we get out? Does EFI enable interrupts and the kernel receives an
interrupt and treats this EFI call like a regular context switch?

> > >  		kernel_neon_begin();
> > >  	} else {
> > 
> > [...]
> > 
> > Cheers
> > ---Dave

Sebastian