On Tue, 2013-06-25 at 09:37 +0200, Peter Zijlstra wrote: > On Mon, Jun 24, 2013 at 01:17:45PM -0700, Tim Chen wrote: > > On second thought, I agree with you. I should change this to > > something like > > > > int retval = true; > > task_struct *sem_owner; > > > > /* Spin only if active writer running */ > > if (!sem->owner) > > return false; > > > > rcu_read_lock(); > > sem_owner = sem->owner; > > That should be: sem_owner = ACCESS_ONCE(sem->owner); to make sure the > compiler doesn't try and be clever and rereads. Thanks. Will incorporate this in next version of the patch. Tim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>