rcu: Rearrange locking in rcu_start_gp()
If CPUs are to give prior notice of needed grace periods, it will be
necessary to invoke rcu_start_gp() without dropping the root rcu_node
structure's ->lock. This commit takes a first step in this direction
by moving the release of this lock to the end of rcu_start_gp().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 7b1d776..2c6a931 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1521,16 +1521,14 @@
raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
-
rsp->gp_flags = RCU_GP_FLAG_INIT;
- raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */
/* Ensure that CPU is aware of completion of last grace period. */
- rcu_process_gp_end(rsp, rdp);
- local_irq_restore(flags);
+ __rcu_process_gp_end(rsp, rdp->mynode, rdp);
/* Wake up rcu_gp_kthread() to start the grace period. */
wake_up(&rsp->gp_wq);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*