On 01/23/2014 12:52 PM, Linus Torvalds wrote:

On Thu, Jan 23, 2014 at 9:47 AM, Waiman Long[off-list ref]  wrote:

quoted

Thank for the info. I am less familiar with that kind of issues on other
architecture. I will add a smp_mb__after_atomic_dec()&  send out a new
patch.

SInce it's the unlock path,. you need to use the "mb__*before*"
versions, since presumably you want to protect what is inside the lock
from leaking out, not some random thing after the lock from leaking
in..

               Linus

My bad. I am a bit sloppy not using the right function in my email. I 
will certainly put the right mb functions depending on whether it is a 
lock or unlock function.

-Longman