Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug updates from Thomas Gleixner:
 "This is the next part of the hotplug rework.

   - Convert all notifiers with a priority assigned

   - Convert all CPU_STARTING/DYING notifiers

     The final removal of the STARTING/DYING infrastructure will happen
     when the merge window closes.

  Another 700 hundred line of unpenetrable maze gone :)"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  timers/core: Correct callback order during CPU hot plug
  leds/trigger/cpu: Move from CPU_STARTING to ONLINE level
  powerpc/numa: Convert to hotplug state machine
  arm/perf: Fix hotplug state machine conversion
  irqchip/armada: Avoid unused function warnings
  ARC/time: Convert to hotplug state machine
  clocksource/atlas7: Convert to hotplug state machine
  clocksource/armada-370-xp: Convert to hotplug state machine
  clocksource/exynos_mct: Convert to hotplug state machine
  clocksource/arm_global_timer: Convert to hotplug state machine
  rcu: Convert rcutree to hotplug state machine
  KVM/arm/arm64/vgic-new: Convert to hotplug state machine
  smp/cfd: Convert core to hotplug state machine
  x86/x2apic: Convert to CPU hotplug state machine
  profile: Convert to hotplug state machine
  timers/core: Convert to hotplug state machine
  hrtimer: Convert to hotplug state machine
  x86/tboot: Convert to hotplug state machine
  arm64/armv8 deprecated: Convert to hotplug state machine
  hwtracing/coresight-etm4x: Convert to hotplug state machine
  ...

1 files changed, 52 insertions, 53 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f433959e9322..5d80925e7fc8 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1073,11 +1073,11 @@ EXPORT_SYMBOL_GPL(rcu_is_watching);
  * offline to continue to use RCU for one jiffy after marking itself
  * offline in the cpu_online_mask.  This leniency is necessary given the
  * non-atomic nature of the online and offline processing, for example,
- * the fact that a CPU enters the scheduler after completing the CPU_DYING
- * notifiers.
+ * the fact that a CPU enters the scheduler after completing the teardown
+ * of the CPU.
  *
- * This is also why RCU internally marks CPUs online during the
- * CPU_UP_PREPARE phase and offline during the CPU_DEAD phase.
+ * This is also why RCU internally marks CPUs online during in the
+ * preparation phase and offline after the CPU has been taken down.
  *
  * Disable checking if in an NMI handler because we cannot safely report
  * errors from NMI handlers anyway.
@@ -3806,12 +3806,58 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
         raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
-static void rcu_prepare_cpu(int cpu)
+int rcutree_prepare_cpu(unsigned int cpu)
 {
         struct rcu_state *rsp;
 
         for_each_rcu_flavor(rsp)
                 rcu_init_percpu_data(cpu, rsp);
+
+        rcu_prepare_kthreads(cpu);
+        rcu_spawn_all_nocb_kthreads(cpu);
+
+        return 0;
+}
+
+static void rcutree_affinity_setting(unsigned int cpu, int outgoing)
+{
+        struct rcu_data *rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
+
+        rcu_boost_kthread_setaffinity(rdp->mynode, outgoing);
+}
+
+int rcutree_online_cpu(unsigned int cpu)
+{
+        sync_sched_exp_online_cleanup(cpu);
+        rcutree_affinity_setting(cpu, -1);
+        return 0;
+}
+
+int rcutree_offline_cpu(unsigned int cpu)
+{
+        rcutree_affinity_setting(cpu, cpu);
+        return 0;
+}
+
+
+int rcutree_dying_cpu(unsigned int cpu)
+{
+        struct rcu_state *rsp;
+
+        for_each_rcu_flavor(rsp)
+                rcu_cleanup_dying_cpu(rsp);
+        return 0;
+}
+
+int rcutree_dead_cpu(unsigned int cpu)
+{
+        struct rcu_state *rsp;
+
+        for_each_rcu_flavor(rsp) {
+                rcu_cleanup_dead_cpu(cpu, rsp);
+                do_nocb_deferred_wakeup(per_cpu_ptr(rsp->rda, cpu));
+        }
+        return 0;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -3851,52 +3897,6 @@ void rcu_report_dead(unsigned int cpu)
 }
 #endif
 
-/*
- * Handle CPU online/offline notification events.
- */
-int rcu_cpu_notify(struct notifier_block *self,
-                   unsigned long action, void *hcpu)
-{
-        long cpu = (long)hcpu;
-        struct rcu_data *rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
-        struct rcu_node *rnp = rdp->mynode;
-        struct rcu_state *rsp;
-
-        switch (action) {
-        case CPU_UP_PREPARE:
-        case CPU_UP_PREPARE_FROZEN:
-                rcu_prepare_cpu(cpu);
-                rcu_prepare_kthreads(cpu);
-                rcu_spawn_all_nocb_kthreads(cpu);
-                break;
-        case CPU_ONLINE:
-        case CPU_DOWN_FAILED:
-                sync_sched_exp_online_cleanup(cpu);
-                rcu_boost_kthread_setaffinity(rnp, -1);
-                break;
-        case CPU_DOWN_PREPARE:
-                rcu_boost_kthread_setaffinity(rnp, cpu);
-                break;
-        case CPU_DYING:
-        case CPU_DYING_FROZEN:
-                for_each_rcu_flavor(rsp)
-                        rcu_cleanup_dying_cpu(rsp);
-                break;
-        case CPU_DEAD:
-        case CPU_DEAD_FROZEN:
-        case CPU_UP_CANCELED:
-        case CPU_UP_CANCELED_FROZEN:
-                for_each_rcu_flavor(rsp) {
-                        rcu_cleanup_dead_cpu(cpu, rsp);
-                        do_nocb_deferred_wakeup(per_cpu_ptr(rsp->rda, cpu));
-                }
-                break;
-        default:
-                break;
-        }
-        return NOTIFY_OK;
-}
-
 static int rcu_pm_notify(struct notifier_block *self,
                          unsigned long action, void *hcpu)
 {
@@ -4208,10 +4208,9 @@ void __init rcu_init(void)
          * this is called early in boot, before either interrupts
          * or the scheduler are operational.
          */
-        cpu_notifier(rcu_cpu_notify, 0);
         pm_notifier(rcu_pm_notify, 0);
         for_each_online_cpu(cpu)
-                rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
+                rcutree_prepare_cpu(cpu);
 }
 
 #include "tree_exp.h"