On Fri, 2010-04-16 at 07:17 -0700, Paul E. McKenney wrote: > > > Of course, with call_rcu_sched(), the corresponding RCU read-side critical > > > sections are non-preemptible. Therefore, in CONFIG_PREEMPT_RT, these > > > read-side critical sections must use raw spinlocks. > > > > OK, so if we fully remove CONFIG_TREE_PREEMPT_RCU (defaulting to y), > > rename all the {call_rcu, rcu_read_lock, rcu_read_unlock, > > synchronize_rcu} functions to {*}_preempt and then add a new > > CONFIG_PREEMPT_RCU that simply maps {*} to either {*}_sched or > > {*}_preempt, we've basically got what I've been asking for for a while, > > no? > > What would rcu_read_lock_preempt() do in a !CONFIG_PREEMPT kernel? Same as for a preempt one, since you'd have to be able to schedule() while holding it to be able to do things like mutex_lock(). -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html