1 files changed, 390 insertions, 237 deletions

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f3077c0ab181..3ec8160fc75f 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -51,22 +51,25 @@
 
 /* Data structures. */
 
+static struct lock_class_key rcu_node_class[NUM_RCU_LVLS];
+
 #define RCU_STATE_INITIALIZER(name) { \
         .level = { &name.node[0] }, \
         .levelcnt = { \
                 NUM_RCU_LVL_0,  /* root of hierarchy. */ \
                 NUM_RCU_LVL_1, \
                 NUM_RCU_LVL_2, \
-                NUM_RCU_LVL_3, /* == MAX_RCU_LVLS */ \
+                NUM_RCU_LVL_3, \
+                NUM_RCU_LVL_4, /* == MAX_RCU_LVLS */ \
         }, \
         .signaled = RCU_GP_IDLE, \
         .gpnum = -300, \
         .completed = -300, \
-        .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
+        .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&name.onofflock), \
         .orphan_cbs_list = NULL, \
         .orphan_cbs_tail = &name.orphan_cbs_list, \
         .orphan_qlen = 0, \
-        .fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
+        .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&name.fqslock), \
         .n_force_qs = 0, \
         .n_force_qs_ngp = 0, \
 }
@@ -77,7 +80,6 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
 struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
 DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
 
-
 /*
  * Return true if an RCU grace period is in progress.  The ACCESS_ONCE()s
  * permit this function to be invoked without holding the root rcu_node
@@ -98,7 +100,7 @@ void rcu_sched_qs(int cpu)
         struct rcu_data *rdp;
 
         rdp = &per_cpu(rcu_sched_data, cpu);
-        rdp->passed_quiesc_completed = rdp->completed;
+        rdp->passed_quiesc_completed = rdp->gpnum - 1;
         barrier();
         rdp->passed_quiesc = 1;
         rcu_preempt_note_context_switch(cpu);
@@ -109,7 +111,7 @@ void rcu_bh_qs(int cpu)
         struct rcu_data *rdp;
 
         rdp = &per_cpu(rcu_bh_data, cpu);
-        rdp->passed_quiesc_completed = rdp->completed;
+        rdp->passed_quiesc_completed = rdp->gpnum - 1;
         barrier();
         rdp->passed_quiesc = 1;
 }
@@ -151,6 +153,24 @@ long rcu_batches_completed_bh(void)
 EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
 
 /*
+ * Force a quiescent state for RCU BH.
+ */
+void rcu_bh_force_quiescent_state(void)
+{
+        force_quiescent_state(&rcu_bh_state, 0);
+}
+EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
+
+/*
+ * Force a quiescent state for RCU-sched.
+ */
+void rcu_sched_force_quiescent_state(void)
+{
+        force_quiescent_state(&rcu_sched_state, 0);
+}
+EXPORT_SYMBOL_GPL(rcu_sched_force_quiescent_state);
+
+/*
  * Does the CPU have callbacks ready to be invoked?
  */
 static int
@@ -335,28 +355,9 @@ void rcu_irq_exit(void)
                 set_need_resched();
 }
 
-/*
- * Record the specified "completed" value, which is later used to validate
- * dynticks counter manipulations.  Specify "rsp->completed - 1" to
- * unconditionally invalidate any future dynticks manipulations (which is
- * useful at the beginning of a grace period).
- */
-static void dyntick_record_completed(struct rcu_state *rsp, long comp)
-{
-        rsp->dynticks_completed = comp;
-}
-
 #ifdef CONFIG_SMP
 
 /*
- * Recall the previously recorded value of the completion for dynticks.
- */
-static long dyntick_recall_completed(struct rcu_state *rsp)
-{
-        return rsp->dynticks_completed;
-}
-
-/*
  * Snapshot the specified CPU's dynticks counter so that we can later
  * credit them with an implicit quiescent state.  Return 1 if this CPU
  * is in dynticks idle mode, which is an extended quiescent state.
@@ -419,24 +420,8 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 
 #else /* #ifdef CONFIG_NO_HZ */
 
-static void dyntick_record_completed(struct rcu_state *rsp, long comp)
-{
-}
-
 #ifdef CONFIG_SMP
 
-/*
- * If there are no dynticks, then the only way that a CPU can passively
- * be in a quiescent state is to be offline.  Unlike dynticks idle, which
- * is a point in time during the prior (already finished) grace period,
- * an offline CPU is always in a quiescent state, and thus can be
- * unconditionally applied.  So just return the current value of completed.
- */
-static long dyntick_recall_completed(struct rcu_state *rsp)
-{
-        return rsp->completed;
-}
-
 static int dyntick_save_progress_counter(struct rcu_data *rdp)
 {
         return 0;
@@ -468,10 +453,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
 
         /* Only let one CPU complain about others per time interval. */
 
-        spin_lock_irqsave(&rnp->lock, flags);
+        raw_spin_lock_irqsave(&rnp->lock, flags);
         delta = jiffies - rsp->jiffies_stall;
         if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
                 return;
         }
         rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
@@ -481,13 +466,15 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
          * due to CPU offlining.
          */
         rcu_print_task_stall(rnp);
-        spin_unlock_irqrestore(&rnp->lock, flags);
+        raw_spin_unlock_irqrestore(&rnp->lock, flags);
 
         /* OK, time to rat on our buddy... */
 
         printk(KERN_ERR "INFO: RCU detected CPU stalls:");
         rcu_for_each_leaf_node(rsp, rnp) {
+                raw_spin_lock_irqsave(&rnp->lock, flags);
                 rcu_print_task_stall(rnp);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
                 if (rnp->qsmask == 0)
                         continue;
                 for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
@@ -498,6 +485,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
                smp_processor_id(), (long)(jiffies - rsp->gp_start));
         trigger_all_cpu_backtrace();
 
+        /* If so configured, complain about tasks blocking the grace period. */
+
+        rcu_print_detail_task_stall(rsp);
+
         force_quiescent_state(rsp, 0);  /* Kick them all. */
 }
 
@@ -510,11 +501,11 @@ static void print_cpu_stall(struct rcu_state *rsp)
                         smp_processor_id(), jiffies - rsp->gp_start);
         trigger_all_cpu_backtrace();
 
-        spin_lock_irqsave(&rnp->lock, flags);
-        if ((long)(jiffies - rsp->jiffies_stall) >= 0)
+        raw_spin_lock_irqsave(&rnp->lock, flags);
+        if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall))
                 rsp->jiffies_stall =
                         jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
-        spin_unlock_irqrestore(&rnp->lock, flags);
+        raw_spin_unlock_irqrestore(&rnp->lock, flags);
 
         set_need_resched();  /* kick ourselves to get things going. */
 }
@@ -553,13 +544,33 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
 /*
  * Update CPU-local rcu_data state to record the newly noticed grace period.
  * This is used both when we started the grace period and when we notice
- * that someone else started the grace period.
+ * that someone else started the grace period.  The caller must hold the
+ * ->lock of the leaf rcu_node structure corresponding to the current CPU,
+ *  and must have irqs disabled.
  */
+static void __note_new_gpnum(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
+{
+        if (rdp->gpnum != rnp->gpnum) {
+                rdp->qs_pending = 1;
+                rdp->passed_quiesc = 0;
+                rdp->gpnum = rnp->gpnum;
+        }
+}
+
 static void note_new_gpnum(struct rcu_state *rsp, struct rcu_data *rdp)
 {
-        rdp->qs_pending = 1;
-        rdp->passed_quiesc = 0;
-        rdp->gpnum = rsp->gpnum;
+        unsigned long flags;
+        struct rcu_node *rnp;
+
+        local_irq_save(flags);
+        rnp = rdp->mynode;
+        if (rdp->gpnum == ACCESS_ONCE(rnp->gpnum) || /* outside lock. */
+            !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */
+                local_irq_restore(flags);
+                return;
+        }
+        __note_new_gpnum(rsp, rnp, rdp);
+        raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
 /*
@@ -583,31 +594,59 @@ check_for_new_grace_period(struct rcu_state *rsp, struct rcu_data *rdp)
 }
 
 /*
- * Start a new RCU grace period if warranted, re-initializing the hierarchy
- * in preparation for detecting the next grace period.  The caller must hold
- * the root node's ->lock, which is released before return.  Hard irqs must
- * be disabled.
+ * Advance this CPU's callbacks, but only if the current grace period
+ * has ended.  This may be called only from the CPU to whom the rdp
+ * belongs.  In addition, the corresponding leaf rcu_node structure's
+ * ->lock must be held by the caller, with irqs disabled.
  */
 static void
-rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
-        __releases(rcu_get_root(rsp)->lock)
+__rcu_process_gp_end(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
 {
-        struct rcu_data *rdp = rsp->rda[smp_processor_id()];
-        struct rcu_node *rnp = rcu_get_root(rsp);
+        /* Did another grace period end? */
+        if (rdp->completed != rnp->completed) {
+
+                /* Advance callbacks.  No harm if list empty. */
+                rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[RCU_WAIT_TAIL];
+                rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_READY_TAIL];
+                rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+
+                /* Remember that we saw this grace-period completion. */
+                rdp->completed = rnp->completed;
+        }
+}
+
+/*
+ * Advance this CPU's callbacks, but only if the current grace period
+ * has ended.  This may be called only from the CPU to whom the rdp
+ * belongs.
+ */
+static void
+rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+        unsigned long flags;
+        struct rcu_node *rnp;
 
-        if (!cpu_needs_another_gp(rsp, rdp)) {
-                spin_unlock_irqrestore(&rnp->lock, flags);
+        local_irq_save(flags);
+        rnp = rdp->mynode;
+        if (rdp->completed == ACCESS_ONCE(rnp->completed) || /* outside lock. */
+            !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */
+                local_irq_restore(flags);
                 return;
         }
+        __rcu_process_gp_end(rsp, rnp, rdp);
+        raw_spin_unlock_irqrestore(&rnp->lock, flags);
+}
 
-        /* Advance to a new grace period and initialize state. */
-        rsp->gpnum++;
-        WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT);
-        rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
-        rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
-        record_gp_stall_check_time(rsp);
-        dyntick_record_completed(rsp, rsp->completed - 1);
-        note_new_gpnum(rsp, rdp);
+/*
+ * Do per-CPU grace-period initialization for running CPU.  The caller
+ * must hold the lock of the leaf rcu_node structure corresponding to
+ * this CPU.
+ */
+static void
+rcu_start_gp_per_cpu(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
+{
+        /* Prior grace period ended, so advance callbacks for current CPU. */
+        __rcu_process_gp_end(rsp, rnp, rdp);
 
         /*
          * Because this CPU just now started the new grace period, we know
@@ -623,21 +662,70 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
         rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
         rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
+        /* Set state so that this CPU will detect the next quiescent state. */
+        __note_new_gpnum(rsp, rnp, rdp);
+}
+
+/*
+ * Start a new RCU grace period if warranted, re-initializing the hierarchy
+ * in preparation for detecting the next grace period.  The caller must hold
+ * the root node's ->lock, which is released before return.  Hard irqs must
+ * be disabled.
+ */
+static void
+rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
+        __releases(rcu_get_root(rsp)->lock)
+{
+        struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+        struct rcu_node *rnp = rcu_get_root(rsp);
+
+        if (!cpu_needs_another_gp(rsp, rdp) || rsp->fqs_active) {
+                if (cpu_needs_another_gp(rsp, rdp))
+                        rsp->fqs_need_gp = 1;
+                if (rnp->completed == rsp->completed) {
+                        raw_spin_unlock_irqrestore(&rnp->lock, flags);
+                        return;
+                }
+                raw_spin_unlock(&rnp->lock);     /* irqs remain disabled. */
+
+                /*
+                 * Propagate new ->completed value to rcu_node structures
+                 * so that other CPUs don't have to wait until the start
+                 * of the next grace period to process their callbacks.
+                 */
+                rcu_for_each_node_breadth_first(rsp, rnp) {
+                        raw_spin_lock(&rnp->lock); /* irqs already disabled. */
+                        rnp->completed = rsp->completed;
+                        raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+                }
+                local_irq_restore(flags);
+                return;
+        }
+
+        /* Advance to a new grace period and initialize state. */
+        rsp->gpnum++;
+        WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT);
+        rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
+        rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
+        record_gp_stall_check_time(rsp);
+
         /* Special-case the common single-level case. */
         if (NUM_RCU_NODES == 1) {
                 rcu_preempt_check_blocked_tasks(rnp);
                 rnp->qsmask = rnp->qsmaskinit;
                 rnp->gpnum = rsp->gpnum;
+                rnp->completed = rsp->completed;
                 rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                rcu_start_gp_per_cpu(rsp, rnp, rdp);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
                 return;
         }
 
-        spin_unlock(&rnp->lock);  /* leave irqs disabled. */
+        raw_spin_unlock(&rnp->lock);  /* leave irqs disabled. */
 
 
         /* Exclude any concurrent CPU-hotplug operations. */
-        spin_lock(&rsp->onofflock);  /* irqs already disabled. */
+        raw_spin_lock(&rsp->onofflock);  /* irqs already disabled. */
 
         /*
          * Set the quiescent-state-needed bits in all the rcu_node
@@ -657,73 +745,50 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
          * irqs disabled.
          */
         rcu_for_each_node_breadth_first(rsp, rnp) {
-                spin_lock(&rnp->lock);          /* irqs already disabled. */
+                raw_spin_lock(&rnp->lock);      /* irqs already disabled. */
                 rcu_preempt_check_blocked_tasks(rnp);
                 rnp->qsmask = rnp->qsmaskinit;
                 rnp->gpnum = rsp->gpnum;
-                spin_unlock(&rnp->lock);        /* irqs remain disabled. */
+                rnp->completed = rsp->completed;
+                if (rnp == rdp->mynode)
+                        rcu_start_gp_per_cpu(rsp, rnp, rdp);
+                raw_spin_unlock(&rnp->lock);    /* irqs remain disabled. */
         }
 
         rnp = rcu_get_root(rsp);
-        spin_lock(&rnp->lock);                  /* irqs already disabled. */
+        raw_spin_lock(&rnp->lock);              /* irqs already disabled. */
         rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
-        spin_unlock(&rnp->lock);                /* irqs remain disabled. */
-        spin_unlock_irqrestore(&rsp->onofflock, flags);
+        raw_spin_unlock(&rnp->lock);            /* irqs remain disabled. */
+        raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
 /*
- * Advance this CPU's callbacks, but only if the current grace period
- * has ended.  This may be called only from the CPU to whom the rdp
- * belongs.
+ * Report a full set of quiescent states to the specified rcu_state
+ * data structure.  This involves cleaning up after the prior grace
+ * period and letting rcu_start_gp() start up the next grace period
+ * if one is needed.  Note that the caller must hold rnp->lock, as
+ * required by rcu_start_gp(), which will release it.
  */
-static void
-rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
-{
-        long completed_snap;
-        unsigned long flags;
-
-        local_irq_save(flags);
-        completed_snap = ACCESS_ONCE(rsp->completed);  /* outside of lock. */
-
-        /* Did another grace period end? */
-        if (rdp->completed != completed_snap) {
-
-                /* Advance callbacks.  No harm if list empty. */
-                rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[RCU_WAIT_TAIL];
-                rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_READY_TAIL];
-                rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
-
-                /* Remember that we saw this grace-period completion. */
-                rdp->completed = completed_snap;
-        }
-        local_irq_restore(flags);
-}
-
-/*
- * Clean up after the prior grace period and let rcu_start_gp() start up
- * the next grace period if one is needed.  Note that the caller must
- * hold rnp->lock, as required by rcu_start_gp(), which will release it.
- */
-static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
+static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
         __releases(rcu_get_root(rsp)->lock)
 {
         WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
         rsp->completed = rsp->gpnum;
         rsp->signaled = RCU_GP_IDLE;
-        rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
         rcu_start_gp(rsp, flags);  /* releases root node's rnp->lock. */
 }
 
 /*
- * Similar to cpu_quiet(), for which it is a helper function.  Allows
- * a group of CPUs to be quieted at one go, though all the CPUs in the
- * group must be represented by the same leaf rcu_node structure.
- * That structure's lock must be held upon entry, and it is released
- * before return.
+ * Similar to rcu_report_qs_rdp(), for which it is a helper function.
+ * Allows quiescent states for a group of CPUs to be reported at one go
+ * to the specified rcu_node structure, though all the CPUs in the group
+ * must be represented by the same rcu_node structure (which need not be
+ * a leaf rcu_node structure, though it often will be).  That structure's
+ * lock must be held upon entry, and it is released before return.
  */
 static void
-cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
-              unsigned long flags)
+rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
+                  struct rcu_node *rnp, unsigned long flags)
         __releases(rnp->lock)
 {
         struct rcu_node *rnp_c;
@@ -733,14 +798,14 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
                 if (!(rnp->qsmask & mask)) {
 
                         /* Our bit has already been cleared, so done. */
-                        spin_unlock_irqrestore(&rnp->lock, flags);
+                        raw_spin_unlock_irqrestore(&rnp->lock, flags);
                         return;
                 }
                 rnp->qsmask &= ~mask;
                 if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {
 
                         /* Other bits still set at this level, so done. */
-                        spin_unlock_irqrestore(&rnp->lock, flags);
+                        raw_spin_unlock_irqrestore(&rnp->lock, flags);
                         return;
                 }
                 mask = rnp->grpmask;
@@ -750,54 +815,56 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
 
                         break;
                 }
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
                 rnp_c = rnp;
                 rnp = rnp->parent;
-                spin_lock_irqsave(&rnp->lock, flags);
+                raw_spin_lock_irqsave(&rnp->lock, flags);
                 WARN_ON_ONCE(rnp_c->qsmask);
         }
 
         /*
          * Get here if we are the last CPU to pass through a quiescent
-         * state for this grace period.  Invoke cpu_quiet_msk_finish()
+         * state for this grace period.  Invoke rcu_report_qs_rsp()
          * to clean up and start the next grace period if one is needed.
          */
-        cpu_quiet_msk_finish(rsp, flags); /* releases rnp->lock. */
+        rcu_report_qs_rsp(rsp, flags); /* releases rnp->lock. */
 }
 
 /*
- * Record a quiescent state for the specified CPU, which must either be
- * the current CPU.  The lastcomp argument is used to make sure we are
- * still in the grace period of interest.  We don't want to end the current
- * grace period based on quiescent states detected in an earlier grace
- * period!
+ * Record a quiescent state for the specified CPU to that CPU's rcu_data
+ * structure.  This must be either called from the specified CPU, or
+ * called when the specified CPU is known to be offline (and when it is
+ * also known that no other CPU is concurrently trying to help the offline
+ * CPU).  The lastcomp argument is used to make sure we are still in the
+ * grace period of interest.  We don't want to end the current grace period
+ * based on quiescent states detected in an earlier grace period!
  */
 static void
-cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
+rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
 {
         unsigned long flags;
         unsigned long mask;
         struct rcu_node *rnp;
 
         rnp = rdp->mynode;
-        spin_lock_irqsave(&rnp->lock, flags);
-        if (lastcomp != ACCESS_ONCE(rsp->completed)) {
+        raw_spin_lock_irqsave(&rnp->lock, flags);
+        if (lastcomp != rnp->completed) {
 
                 /*
                  * Someone beat us to it for this grace period, so leave.
                  * The race with GP start is resolved by the fact that we
                  * hold the leaf rcu_node lock, so that the per-CPU bits
                  * cannot yet be initialized -- so we would simply find our
-                 * CPU's bit already cleared in cpu_quiet_msk() if this race
-                 * occurred.
+                 * CPU's bit already cleared in rcu_report_qs_rnp() if this
+                 * race occurred.
                  */
                 rdp->passed_quiesc = 0; /* try again later! */
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
                 return;
         }
         mask = rdp->grpmask;
         if ((rnp->qsmask & mask) == 0) {
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
         } else {
                 rdp->qs_pending = 0;
 
@@ -807,7 +874,7 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
                  */
                 rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
-                cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
+                rcu_report_qs_rnp(mask, rsp, rnp, flags); /* rlses rnp->lock */
         }
 }
 
@@ -838,8 +905,11 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
         if (!rdp->passed_quiesc)
                 return;
 
-        /* Tell RCU we are done (but cpu_quiet() will be the judge of that). */
-        cpu_quiet(rdp->cpu, rsp, rdp, rdp->passed_quiesc_completed);
+        /*
+         * Tell RCU we are done (but rcu_report_qs_rdp() will be the
+         * judge of that).
+         */
+        rcu_report_qs_rdp(rdp->cpu, rsp, rdp, rdp->passed_quiesc_completed);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -858,7 +928,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
 
         if (rdp->nxtlist == NULL)
                 return;  /* irqs disabled, so comparison is stable. */
-        spin_lock(&rsp->onofflock);  /* irqs already disabled. */
+        raw_spin_lock(&rsp->onofflock);  /* irqs already disabled. */
         *rsp->orphan_cbs_tail = rdp->nxtlist;
         rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];
         rdp->nxtlist = NULL;
@@ -866,7 +936,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
                 rdp->nxttail[i] = &rdp->nxtlist;
         rsp->orphan_qlen += rdp->qlen;
         rdp->qlen = 0;
-        spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */
+        raw_spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */
 }
 
 /*
@@ -877,10 +947,10 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
         unsigned long flags;
         struct rcu_data *rdp;
 
-        spin_lock_irqsave(&rsp->onofflock, flags);
+        raw_spin_lock_irqsave(&rsp->onofflock, flags);
         rdp = rsp->rda[smp_processor_id()];
         if (rsp->orphan_cbs_list == NULL) {
-                spin_unlock_irqrestore(&rsp->onofflock, flags);
+                raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
                 return;
         }
         *rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
@@ -889,7 +959,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
         rsp->orphan_cbs_list = NULL;
         rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
         rsp->orphan_qlen = 0;
-        spin_unlock_irqrestore(&rsp->onofflock, flags);
+        raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
 /*
@@ -899,45 +969,47 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
 static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
 {
         unsigned long flags;
-        long lastcomp;
         unsigned long mask;
+        int need_report = 0;
         struct rcu_data *rdp = rsp->rda[cpu];
         struct rcu_node *rnp;
 
         /* Exclude any attempts to start a new grace period. */
-        spin_lock_irqsave(&rsp->onofflock, flags);
+        raw_spin_lock_irqsave(&rsp->onofflock, flags);
 
         /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */
         rnp = rdp->mynode;      /* this is the outgoing CPU's rnp. */
         mask = rdp->grpmask;    /* rnp->grplo is constant. */
         do {
-                spin_lock(&rnp->lock);          /* irqs already disabled. */
+                raw_spin_lock(&rnp->lock);      /* irqs already disabled. */
                 rnp->qsmaskinit &= ~mask;
                 if (rnp->qsmaskinit != 0) {
-                        spin_unlock(&rnp->lock); /* irqs remain disabled. */
+                        if (rnp != rdp->mynode)
+                                raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
                         break;
                 }
-
-                /*
-                 * If there was a task blocking the current grace period,
-                 * and if all CPUs have checked in, we need to propagate
-                 * the quiescent state up the rcu_node hierarchy.  But that
-                 * is inconvenient at the moment due to deadlock issues if
-                 * this should end the current grace period.  So set the
-                 * offlined CPU's bit in ->qsmask in order to force the
-                 * next force_quiescent_state() invocation to clean up this
-                 * mess in a deadlock-free manner.
-                 */
-                if (rcu_preempt_offline_tasks(rsp, rnp, rdp) && !rnp->qsmask)
-                        rnp->qsmask |= mask;
-
+                if (rnp == rdp->mynode)
+                        need_report = rcu_preempt_offline_tasks(rsp, rnp, rdp);
+                else
+                        raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
                 mask = rnp->grpmask;
-                spin_unlock(&rnp->lock);        /* irqs remain disabled. */
                 rnp = rnp->parent;
         } while (rnp != NULL);
-        lastcomp = rsp->completed;
 
-        spin_unlock_irqrestore(&rsp->onofflock, flags);
+        /*
+         * We still hold the leaf rcu_node structure lock here, and
+         * irqs are still disabled.  The reason for this subterfuge is
+         * because invoking rcu_report_unblock_qs_rnp() with ->onofflock
+         * held leads to deadlock.
+         */
+        raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
+        rnp = rdp->mynode;
+        if (need_report & RCU_OFL_TASKS_NORM_GP)
+                rcu_report_unblock_qs_rnp(rnp, flags);
+        else
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
+        if (need_report & RCU_OFL_TASKS_EXP_GP)
+                rcu_report_exp_rnp(rsp, rnp);
 
         rcu_adopt_orphan_cbs(rsp);
 }
@@ -1094,11 +1166,9 @@ void rcu_check_callbacks(int cpu, int user)
 /*
  * Scan the leaf rcu_node structures, processing dyntick state for any that
  * have not yet encountered a quiescent state, using the function specified.
- * Returns 1 if the current grace period ends while scanning (possibly
- * because we made it end).
+ * The caller must have suppressed start of new grace periods.
  */
-static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
-                               int (*f)(struct rcu_data *))
+static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *))
 {
         unsigned long bit;
         int cpu;
@@ -1108,13 +1178,13 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
 
         rcu_for_each_leaf_node(rsp, rnp) {
                 mask = 0;
-                spin_lock_irqsave(&rnp->lock, flags);
-                if (rsp->completed != lastcomp) {
-                        spin_unlock_irqrestore(&rnp->lock, flags);
-                        return 1;
+                raw_spin_lock_irqsave(&rnp->lock, flags);
+                if (!rcu_gp_in_progress(rsp)) {
+                        raw_spin_unlock_irqrestore(&rnp->lock, flags);
+                        return;
                 }
                 if (rnp->qsmask == 0) {
-                        spin_unlock_irqrestore(&rnp->lock, flags);
+                        raw_spin_unlock_irqrestore(&rnp->lock, flags);
                         continue;
                 }
                 cpu = rnp->grplo;
@@ -1123,15 +1193,14 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
                         if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
                                 mask |= bit;
                 }
-                if (mask != 0 && rsp->completed == lastcomp) {
+                if (mask != 0) {
 
-                        /* cpu_quiet_msk() releases rnp->lock. */
-                        cpu_quiet_msk(mask, rsp, rnp, flags);
+                        /* rcu_report_qs_rnp() releases rnp->lock. */
+                        rcu_report_qs_rnp(mask, rsp, rnp, flags);
                         continue;
                 }
-                spin_unlock_irqrestore(&rnp->lock, flags);
+                raw_spin_unlock_irqrestore(&rnp->lock, flags);
         }
-        return 0;
 }
 
 /*
@@ -1141,31 +1210,26 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
 static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
 {
         unsigned long flags;
-        long lastcomp;
         struct rcu_node *rnp = rcu_get_root(rsp);
-        u8 signaled;
 
         if (!rcu_gp_in_progress(rsp))
                 return;  /* No grace period in progress, nothing to force. */
-        if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
+        if (!raw_spin_trylock_irqsave(&rsp->fqslock, flags)) {
                 rsp->n_force_qs_lh++; /* Inexact, can lose counts.  Tough! */
                 return; /* Someone else is already on the job. */
         }
-        if (relaxed &&
-            (long)(rsp->jiffies_force_qs - jiffies) >= 0)
-                goto unlock_ret; /* no emergency and done recently. */
+        if (relaxed && ULONG_CMP_GE(rsp->jiffies_force_qs, jiffies))
+                goto unlock_fqs_ret; /* no emergency and done recently. */
         rsp->n_force_qs++;
-        spin_lock(&rnp->lock);
-        lastcomp = rsp->completed;
-        signaled = rsp->signaled;
+        raw_spin_lock(&rnp->lock);  /* irqs already disabled */
         rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
-        if (lastcomp == rsp->gpnum) {
+        if(!rcu_gp_in_progress(rsp)) {
                 rsp->n_force_qs_ngp++;
-                spin_unlock(&rnp->lock);
-                goto unlock_ret;  /* no GP in progress, time updated. */
+                raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */
+                goto unlock_fqs_ret;  /* no GP in progress, time updated. */
         }
-        spin_unlock(&rnp->lock);
-        switch (signaled) {
+        rsp->fqs_active = 1;
+        switch (rsp->signaled) {
         case RCU_GP_IDLE:
         case RCU_GP_INIT:
 
@@ -1173,37 +1237,38 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
 
         case RCU_SAVE_DYNTICK:
 
+                raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */
                 if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK)
                         break; /* So gcc recognizes the dead code. */
 
                 /* Record dyntick-idle state. */
-                if (rcu_process_dyntick(rsp, lastcomp,
-                                        dyntick_save_progress_counter))
-                        goto unlock_ret;
-
-                /* Update state, record completion counter. */
-                spin_lock(&rnp->lock);
-                if (lastcomp == rsp->completed &&
-                    rsp->signaled == RCU_SAVE_DYNTICK) {
+                force_qs_rnp(rsp, dyntick_save_progress_counter);
+                raw_spin_lock(&rnp->lock);  /* irqs already disabled */
+                if (rcu_gp_in_progress(rsp))
                         rsp->signaled = RCU_FORCE_QS;
-                        dyntick_record_completed(rsp, lastcomp);
-                }
-                spin_unlock(&rnp->lock);
                 break;
 
         case RCU_FORCE_QS:
 
                 /* Check dyntick-idle state, send IPI to laggarts. */
-                if (rcu_process_dyntick(rsp, dyntick_recall_completed(rsp),
-                                        rcu_implicit_dynticks_qs))
-                        goto unlock_ret;
+                raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */
+                force_qs_rnp(rsp, rcu_implicit_dynticks_qs);
 
                 /* Leave state in case more forcing is required. */
 
+                raw_spin_lock(&rnp->lock);  /* irqs already disabled */
                 break;
         }
-unlock_ret:
-        spin_unlock_irqrestore(&rsp->fqslock, flags);
+        rsp->fqs_active = 0;
+        if (rsp->fqs_need_gp) {
+                raw_spin_unlock(&rsp->fqslock); /* irqs remain disabled */
+                rsp->fqs_need_gp = 0;
+                rcu_start_gp(rsp, flags); /* releases rnp->lock */
+                return;
+        }
+        raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */
+unlock_fqs_ret:
+        raw_spin_unlock_irqrestore(&rsp->fqslock, flags);
 }
 
 #else /* #ifdef CONFIG_SMP */
@@ -1231,7 +1296,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
          * If an RCU GP has gone long enough, go check for dyntick
          * idle CPUs and, if needed, send resched IPIs.
          */
-        if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)
+        if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies))
                 force_quiescent_state(rsp, 1);
 
         /*
@@ -1245,7 +1310,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
 
         /* Does this CPU require a not-yet-started grace period? */
         if (cpu_needs_another_gp(rsp, rdp)) {
-                spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
+                raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
                 rcu_start_gp(rsp, flags);  /* releases above lock */
         }
 
@@ -1276,6 +1341,9 @@ static void rcu_process_callbacks(struct softirq_action *unused)
          * grace-period manipulations above.
          */
         smp_mb(); /* See above block comment. */
+
+        /* If we are last CPU on way to dyntick-idle mode, accelerate it. */
+        rcu_needs_cpu_flush();
 }
 
 static void
@@ -1310,7 +1378,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
                 unsigned long nestflag;
                 struct rcu_node *rnp_root = rcu_get_root(rsp);
 
-                spin_lock_irqsave(&rnp_root->lock, nestflag);
+                raw_spin_lock_irqsave(&rnp_root->lock, nestflag);
                 rcu_start_gp(rsp, nestflag);  /* releases rnp_root->lock. */
         }
 
@@ -1328,7 +1396,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
                         force_quiescent_state(rsp, 0);
                 rdp->n_force_qs_snap = rsp->n_force_qs;
                 rdp->qlen_last_fqs_check = rdp->qlen;
-        } else if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)
+        } else if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies))
                 force_quiescent_state(rsp, 1);
         local_irq_restore(flags);
 }
@@ -1351,6 +1419,68 @@ void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 }
 EXPORT_SYMBOL_GPL(call_rcu_bh);
 
+/**
+ * synchronize_sched - wait until an rcu-sched grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu-sched
+ * grace period has elapsed, in other words after all currently executing
+ * rcu-sched read-side critical sections have completed.   These read-side
+ * critical sections are delimited by rcu_read_lock_sched() and
+ * rcu_read_unlock_sched(), and may be nested.  Note that preempt_disable(),
+ * local_irq_disable(), and so on may be used in place of
+ * rcu_read_lock_sched().
+ *
+ * This means that all preempt_disable code sequences, including NMI and
+ * hardware-interrupt handlers, in progress on entry will have completed
+ * before this primitive returns.  However, this does not guarantee that
+ * softirq handlers will have completed, since in some kernels, these
+ * handlers can run in process context, and can block.
+ *
+ * This primitive provides the guarantees made by the (now removed)
+ * synchronize_kernel() API.  In contrast, synchronize_rcu() only
+ * guarantees that rcu_read_lock() sections will have completed.
+ * In "classic RCU", these two guarantees happen to be one and
+ * the same, but can differ in realtime RCU implementations.
+ */
+void synchronize_sched(void)
+{
+        struct rcu_synchronize rcu;
+
+        if (rcu_blocking_is_gp())
+                return;
+
+        init_completion(&rcu.completion);
+        /* Will wake me after RCU finished. */
+        call_rcu_sched(&rcu.head, wakeme_after_rcu);
+        /* Wait for it. */
+        wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_sched);
+
+/**
+ * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu_bh grace
+ * period has elapsed, in other words after all currently executing rcu_bh
+ * read-side critical sections have completed.  RCU read-side critical
+ * sections are delimited by rcu_read_lock_bh() and rcu_read_unlock_bh(),
+ * and may be nested.
+ */
+void synchronize_rcu_bh(void)
+{
+        struct rcu_synchronize rcu;
+
+        if (rcu_blocking_is_gp())
+                return;
+
+        init_completion(&rcu.completion);
+        /* Will wake me after RCU finished. */
+        call_rcu_bh(&rcu.head, wakeme_after_rcu);
+        /* Wait for it. */
+        wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+
 /*
  * Check to see if there is any immediate RCU-related work to be done
  * by the current CPU, for the specified type of RCU, returning 1 if so.
@@ -1360,6 +1490,8 @@ EXPORT_SYMBOL_GPL(call_rcu_bh);
  */
 static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
 {
+        struct rcu_node *rnp = rdp->mynode;
+
         rdp->n_rcu_pending++;
 
         /* Check for CPU stalls, if enabled. */
@@ -1384,20 +1516,20 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
         }
 
         /* Has another RCU grace period completed?  */
-        if (ACCESS_ONCE(rsp->completed) != rdp->completed) { /* outside lock */
+        if (ACCESS_ONCE(rnp->completed) != rdp->completed) { /* outside lock */
                 rdp->n_rp_gp_completed++;
                 return 1;
         }
 
         /* Has a new RCU grace period started? */
-        if (ACCESS_ONCE(rsp->gpnum) != rdp->gpnum) { /* outside lock */
+        if (ACCESS_ONCE(rnp->gpnum) != rdp->gpnum) { /* outside lock */
                 rdp->n_rp_gp_started++;
                 return 1;
         }
 
         /* Has an RCU GP gone long enough to send resched IPIs &c? */
         if (rcu_gp_in_progress(rsp) &&
-            ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
+            ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies)) {
                 rdp->n_rp_need_fqs++;
                 return 1;
         }
@@ -1422,10 +1554,9 @@ static int rcu_pending(int cpu)
 /*
  * Check to see if any future RCU-related work will need to be done
  * by the current CPU, even if none need be done immediately, returning
- * 1 if so.  This function is part of the RCU implementation; it is -not-
- * an exported member of the RCU API.
+ * 1 if so.
  */
-int rcu_needs_cpu(int cpu)
+static int rcu_needs_cpu_quick_check(int cpu)
 {
         /* RCU callbacks either ready or pending? */
         return per_cpu(rcu_sched_data, cpu).nxtlist ||
@@ -1521,7 +1652,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
         struct rcu_node *rnp = rcu_get_root(rsp);
 
         /* Set up local state, ensuring consistent view of global state. */
-        spin_lock_irqsave(&rnp->lock, flags);
+        raw_spin_lock_irqsave(&rnp->lock, flags);
         rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
         rdp->nxtlist = NULL;
         for (i = 0; i < RCU_NEXT_SIZE; i++)
@@ -1531,7 +1662,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
         rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
 #endif /* #ifdef CONFIG_NO_HZ */
         rdp->cpu = cpu;
-        spin_unlock_irqrestore(&rnp->lock, flags);
+        raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
 /*
@@ -1544,25 +1675,20 @@ static void __cpuinit
 rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
 {
         unsigned long flags;
-        long lastcomp;
         unsigned long mask;
         struct rcu_data *rdp = rsp->rda[cpu];
         struct rcu_node *rnp = rcu_get_root(rsp);
 
         /* Set up local state, ensuring consistent view of global state. */
-        spin_lock_irqsave(&rnp->lock, flags);
-        lastcomp = rsp->completed;
-        rdp->completed = lastcomp;
-        rdp->gpnum = lastcomp;
+        raw_spin_lock_irqsave(&rnp->lock, flags);
         rdp->passed_quiesc = 0;  /* We could be racing with new GP, */
         rdp->qs_pending = 1;     /*  so set up to respond to current GP. */
         rdp->beenonline = 1;     /* We have now been online. */
         rdp->preemptable = preemptable;
-        rdp->passed_quiesc_completed = lastcomp - 1;
         rdp->qlen_last_fqs_check = 0;
         rdp->n_force_qs_snap = rsp->n_force_qs;
         rdp->blimit = blimit;
-        spin_unlock(&rnp->lock);                /* irqs remain disabled. */
+        raw_spin_unlock(&rnp->lock);            /* irqs remain disabled. */
 
         /*
          * A new grace period might start here.  If so, we won't be part
@@ -1570,21 +1696,26 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
          */
 
         /* Exclude any attempts to start a new GP on large systems. */
-        spin_lock(&rsp->onofflock);             /* irqs already disabled. */
+        raw_spin_lock(&rsp->onofflock);         /* irqs already disabled. */
 
         /* Add CPU to rcu_node bitmasks. */
         rnp = rdp->mynode;
         mask = rdp->grpmask;
         do {
                 /* Exclude any attempts to start a new GP on small systems. */
-                spin_lock(&rnp->lock);  /* irqs already disabled. */
+                raw_spin_lock(&rnp->lock);      /* irqs already disabled. */
                 rnp->qsmaskinit |= mask;
                 mask = rnp->grpmask;
-                spin_unlock(&rnp->lock); /* irqs already disabled. */
+                if (rnp == rdp->mynode) {
+                        rdp->gpnum = rnp->completed; /* if GP in progress... */
+                        rdp->completed = rnp->completed;
+                        rdp->passed_quiesc_completed = rnp->completed - 1;
+                }
+                raw_spin_unlock(&rnp->lock); /* irqs already disabled. */
                 rnp = rnp->parent;
         } while (rnp != NULL && !(rnp->qsmaskinit & mask));
 
-        spin_unlock_irqrestore(&rsp->onofflock, flags);
+        raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
 static void __cpuinit rcu_online_cpu(int cpu)
@@ -1597,8 +1728,8 @@ static void __cpuinit rcu_online_cpu(int cpu)
 /*
  * Handle CPU online/offline notification events.
  */
-int __cpuinit rcu_cpu_notify(struct notifier_block *self,
-                             unsigned long action, void *hcpu)
+static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
+                                    unsigned long action, void *hcpu)
 {
         long cpu = (long)hcpu;
 
@@ -1668,11 +1799,17 @@ static void __init rcu_init_levelspread(struct rcu_state *rsp)
  */
 static void __init rcu_init_one(struct rcu_state *rsp)
 {
+        static char *buf[] = { "rcu_node_level_0",
+                               "rcu_node_level_1",
+                               "rcu_node_level_2",
+                               "rcu_node_level_3" };  /* Match MAX_RCU_LVLS */
         int cpustride = 1;
         int i;
         int j;
         struct rcu_node *rnp;
 
+        BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf));  /* Fix buf[] init! */
+
         /* Initialize the level-tracking arrays. */
 
         for (i = 1; i < NUM_RCU_LVLS; i++)
@@ -1685,8 +1822,9 @@ static void __init rcu_init_one(struct rcu_state *rsp)
                 cpustride *= rsp->levelspread[i];
                 rnp = rsp->level[i];
                 for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
-                        if (rnp != rcu_get_root(rsp))
-                                spin_lock_init(&rnp->lock);
+                        raw_spin_lock_init(&rnp->lock);
+                        lockdep_set_class_and_name(&rnp->lock,
+                                                   &rcu_node_class[i], buf[i]);
                         rnp->gpnum = 0;
                         rnp->qsmask = 0;
                         rnp->qsmaskinit = 0;
@@ -1707,9 +1845,10 @@ static void __init rcu_init_one(struct rcu_state *rsp)
                         rnp->level = i;
                         INIT_LIST_HEAD(&rnp->blocked_tasks[0]);
                         INIT_LIST_HEAD(&rnp->blocked_tasks[1]);
+                        INIT_LIST_HEAD(&rnp->blocked_tasks[2]);
+                        INIT_LIST_HEAD(&rnp->blocked_tasks[3]);
                 }
         }
-        spin_lock_init(&rcu_get_root(rsp)->lock);
 }
 
 /*
@@ -1735,16 +1874,30 @@ do { \
         } \
 } while (0)
 
-void __init __rcu_init(void)
+void __init rcu_init(void)
 {
+        int cpu;
+
         rcu_bootup_announce();
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
         printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+#if NUM_RCU_LVL_4 != 0
+        printk(KERN_INFO "Experimental four-level hierarchy is enabled.\n");
+#endif /* #if NUM_RCU_LVL_4 != 0 */
         RCU_INIT_FLAVOR(&rcu_sched_state, rcu_sched_data);
         RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data);
         __rcu_init_preempt();
         open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+
+        /*
+         * We don't need protection against CPU-hotplug here because
+         * this is called early in boot, before either interrupts
+         * or the scheduler are operational.
+         */
+        cpu_notifier(rcu_cpu_notify, 0);
+        for_each_online_cpu(cpu)
+                rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
 }
 
 #include "rcutree_plugin.h"