Because there is no longer any preempted tasks on the root rcu_node, and
because there is no longer ever an rcub kthread for the root rcu_node,
this commit drops the code in force_qs_rnp() that attempts to awaken
the non-existent root rcub kthread. This is strictly a performance
enhancement, removing a root rcu_node ->lock acquisition and release
along with some tests in rcu_initiate_boost(), ending with the test that
notes that there is no rcub kthread.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
}
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
- rnp = rcu_get_root(rsp);
- if (rnp->qsmask == 0) {
- raw_spin_lock_irqsave(&rnp->lock, flags);
- smp_mb__after_unlock_lock();
- rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */
- }
}
/*