> #define preempt_disable() barrier() > ...... > #define preempt_enable() barrier()
Let me try answering this with a limited knowledge I have about barriers. barrier() essentially was added so that compiler reordering does not happen. In the code above, since the compiler does not know/understand the specialty of preempt_[enable/disable], the compiler might decide to change the ordering. In this case, where the code is disabling/enabling preemption, barrier() tells the compiler that it can't move stuff around. I hope this helps. - Doug _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
