* Peter Zijlstra <[email protected]> wrote:
> > It might even be that this is the defined semantics of spin_unlock_wait().
>
> As is, spin_unlock_wait() is somewhat ill defined. IIRC it grew from an
> optimization by Oleg and subsequently got used elsewhere. And it being the
> subtle bugger it is, there were bugs.
I believe the historical, original spin_unlock_wait() came from early SMP
optimizations of the networking code - and then spread elsewhere, step by step.
All but one of the networking uses went away since then - so I don't think
there's
any original usecase left.
Thanks,
Ingo