Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory barrier (v5)

Steven Rostedt
2010-01-21T16:12:19Z

On Thu, 2010-01-21 at 11:07 -0500, Mathieu Desnoyers wrote:
> * Peter Zijlstra (peterz@infradead.org) wrote:

> We can even create a generic fallback with the following kind of code in
> the meantime:
>
> static inline void spin_lock_mb(spinlock_t *lock)
> {
> spin_lock(&lock);

That would be spin_lock(lock);

> smp_mb();
> }
>
> static inline void spin_unlock_mb(spinlock_t *lock)
> {
> smp_mb();
> spin_unlock(&lock);

and spin_unlock(lock);

;-)

> }
>
> How does that sound ?

You may also need spin_lock_irqsave, et al. variants too.

-- Steve