Paul E. McKenney, IBM Linux Technology Center

With the 3.0 release, the -rt patchset introduced migrate_disable() to permit better handling of per-CPU variables and preempt_disable() and local_bh_disable() regions. However, there is some reason to believe that this approach might defeat load balancing and therefore reduce utilization, thereby increasing the response times for non-highest-priority tasks. This talk will look at a mathematical model of migration disabling to quantify this effect, and possibly put forward ways of ameliorating it.