Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions

[Linus Torvalds]

On Mon, Jul 3, 2017 at 3:30 PM, Paul E. McKenney
<paulmck@xxxxxxxxxxxxxxxxxx> wrote:
>
> That certainly is one interesting function, isn't it?  I wonder what
> happens if you replace the raw_spin_is_locked() calls with an
> unlock under a trylock check?  ;-)

Deadlock due to interrupts again?

Didn't your spin_unlock_wait() patches teach you anything? Checking
state is fundamentally different from taking the lock. Even a trylock.

I guess you could try with the irqsave versions. But no, we're not doing that.

                Linus