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. > if (sem_owner) > retval = sem_owner->on_cpu; > -- 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>