Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming

[pandora-kernel.git] / kernel / rcutree.c

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 4fb2376..74df86b 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -74,6 +74,7 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
        .orphan_nxttail = &sname##_state.orphan_nxtlist, \
        .orphan_donetail = &sname##_state.orphan_donelist, \
        .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
+       .onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
        .name = #sname, \
 }
 
@@ -1197,7 +1198,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
        raw_spin_unlock_irq(&rnp->lock);
 
        /* Exclude any concurrent CPU-hotplug operations. */
-       get_online_cpus();
+       mutex_lock(&rsp->onoff_mutex);
 
        /*
         * Set the quiescent-state-needed bits in all the rcu_node
@@ -1234,7 +1235,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
                cond_resched();
        }
 
-       put_online_cpus();
+       mutex_unlock(&rsp->onoff_mutex);
        return 1;
 }
 
@@ -1700,6 +1701,7 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp)
        /* Remove the dead CPU from the bitmasks in the rcu_node hierarchy. */
 
        /* Exclude any attempts to start a new grace period. */
+       mutex_lock(&rsp->onoff_mutex);
        raw_spin_lock_irqsave(&rsp->onofflock, flags);
 
        /* Orphan the dead CPU's callbacks, and adopt them if appropriate. */
@@ -1744,6 +1746,7 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp)
        init_callback_list(rdp);
        /* Disallow further callbacks on this CPU. */
        rdp->nxttail[RCU_NEXT_TAIL] = NULL;
+       mutex_unlock(&rsp->onoff_mutex);
 }
 
 #else /* #ifdef CONFIG_HOTPLUG_CPU */
@@ -2648,6 +2651,9 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
        struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
        struct rcu_node *rnp = rcu_get_root(rsp);
 
+       /* Exclude new grace periods. */
+       mutex_lock(&rsp->onoff_mutex);
+
        /* Set up local state, ensuring consistent view of global state. */
        raw_spin_lock_irqsave(&rnp->lock, flags);
        rdp->beenonline = 1;     /* We have now been online. */
@@ -2662,14 +2668,6 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
        rcu_prepare_for_idle_init(cpu);
        raw_spin_unlock(&rnp->lock);            /* irqs remain disabled. */
 
-       /*
-        * A new grace period might start here.  If so, we won't be part
-        * of it, but that is OK, as we are currently in a quiescent state.
-        */
-
-       /* Exclude any attempts to start a new GP on large systems. */
-       raw_spin_lock(&rsp->onofflock);         /* irqs already disabled. */
-
        /* Add CPU to rcu_node bitmasks. */
        rnp = rdp->mynode;
        mask = rdp->grpmask;
@@ -2693,8 +2691,9 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
                raw_spin_unlock(&rnp->lock); /* irqs already disabled. */
                rnp = rnp->parent;
        } while (rnp != NULL && !(rnp->qsmaskinit & mask));
+       local_irq_restore(flags);
 
-       raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
+       mutex_unlock(&rsp->onoff_mutex);
 }
 
 static void __cpuinit rcu_prepare_cpu(int cpu)