Re: [PATCH] locking/mutex: Set and clear owner using WRITE_ONCE()

[Davidlohr Bueso]

On Thu, 19 May 2016, Jason Low wrote:

> The mutex owner can get read and written to without the wait_lock.
> Use WRITE_ONCE when setting and clearing the owner field in order
> to avoid optimizations such as store tearing. This avoids
> situations where the owner field gets written to with multiple
> stores and another thread could concurrently read and use a
> partially written owner value.

Right, I also ran into this with rtmutexes when avoiding the schedule()
and the spin on owner thingie.

> Signed-off-by: Jason Low <jason.low2@xxxxxxx>

Acked-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>