On 02/05/2015 01:56 PM, Paul E. McKenney wrote: > The real danger is doing neither. > > On tick_nohz_full_cpu() CPUs, the exit-to-userspace code should invoke > rcu_user_enter(), which sets some per-CPU state telling RCU to ignore > that CPU, since it cannot possibly do host RCU read-side critical sections > while running a guest. > > In contrast, a non-tick_nohz_full_cpu() CPU doesn't let RCU > know that it is executing in a guest or in userspace. So the > rcu_virt_note_context_switch() does the notification in that case. Looking at context_tracking.h, I see the function context_tracking_cpu_is_enabled(). That looks like it should do the right thing in this case. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
