rcu: Introduce proper blocking to no-CBs kthreads GP waits

[deliverable/linux.git] / kernel / rcutree.c

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6ad0716e65dc50d7b60bb08de663d80dd2bf948d..433f426c848f92fa6e93666c89692f7807b78ee1 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -310,7 +310,7 @@ cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
 
        if (rcu_gp_in_progress(rsp))
                return 0;  /* No, a grace period is already in progress. */
-       if (rcu_nocb_needs_gp(rdp))
+       if (rcu_nocb_needs_gp(rsp))
                return 1;  /* Yes, a no-CBs CPU needs one. */
        if (!rdp->nxttail[RCU_NEXT_TAIL])
                return 0;  /* No, this is a no-CBs (or offline) CPU. */
@@ -1364,6 +1364,7 @@ int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
 static void rcu_gp_cleanup(struct rcu_state *rsp)
 {
        unsigned long gp_duration;
+       int nocb = 0;
        struct rcu_data *rdp;
        struct rcu_node *rnp = rcu_get_root(rsp);
 
@@ -1394,11 +1395,13 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
        rcu_for_each_node_breadth_first(rsp, rnp) {
                raw_spin_lock_irq(&rnp->lock);
                rnp->completed = rsp->gpnum;
+               nocb += rcu_nocb_gp_cleanup(rsp, rnp);
                raw_spin_unlock_irq(&rnp->lock);
                cond_resched();
        }
        rnp = rcu_get_root(rsp);
        raw_spin_lock_irq(&rnp->lock);
+       rcu_nocb_gp_set(rnp, nocb);
 
        rsp->completed = rsp->gpnum; /* Declare grace period done. */
        trace_rcu_grace_period(rsp->name, rsp->completed, "end");
@@ -3084,6 +3087,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
                        }
                        rnp->level = i;
                        INIT_LIST_HEAD(&rnp->blkd_tasks);
+                       rcu_init_one_nocb(rnp);
                }
        }