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 final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

2 files changed, 26 insertions, 24 deletions

diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 72d36113ccaa..c8cebb137076 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -158,25 +158,21 @@ EXPORT_SYMBOL(percpu_counter_destroy);
 int percpu_counter_batch __read_mostly = 32;
 EXPORT_SYMBOL(percpu_counter_batch);
 
-static void compute_batch_value(void)
+static int compute_batch_value(unsigned int cpu)
 {
 	int nr = num_online_cpus();
 
 	percpu_counter_batch = max(32, nr*2);
+	return 0;
 }
 
-static int percpu_counter_hotcpu_callback(struct notifier_block *nb,
-					unsigned long action, void *hcpu)
+static int percpu_counter_cpu_dead(unsigned int cpu)
 {
 #ifdef CONFIG_HOTPLUG_CPU
-	unsigned int cpu;
 	struct percpu_counter *fbc;
 
-	compute_batch_value();
-	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
-		return NOTIFY_OK;
+	compute_batch_value(cpu);
 
-	cpu = (unsigned long)hcpu;
 	spin_lock_irq(&percpu_counters_lock);
 	list_for_each_entry(fbc, &percpu_counters, list) {
 		s32 *pcount;
@@ -190,7 +186,7 @@ static int percpu_counter_hotcpu_callback(struct notifier_block *nb,
 	}
 	spin_unlock_irq(&percpu_counters_lock);
 #endif
-	return NOTIFY_OK;
+	return 0;
 }
 
 /*
@@ -222,8 +218,15 @@ EXPORT_SYMBOL(__percpu_counter_compare);
 
 static int __init percpu_counter_startup(void)
 {
-	compute_batch_value();
-	hotcpu_notifier(percpu_counter_hotcpu_callback, 0);
+	int ret;
+
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "lib/percpu_cnt:online",
+				compute_batch_value, NULL);
+	WARN_ON(ret < 0);
+	ret = cpuhp_setup_state_nocalls(CPUHP_PERCPU_CNT_DEAD,
+					"lib/percpu_cnt:dead", NULL,
+					percpu_counter_cpu_dead);
+	WARN_ON(ret < 0);
 	return 0;
 }
 module_init(percpu_counter_startup);
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8e6d552c40dd..4b8bb3618b83 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1642,32 +1642,31 @@ static __init void radix_tree_init_maxnodes(void)
 	}
 }
 
-static int radix_tree_callback(struct notifier_block *nfb,
-				unsigned long action, void *hcpu)
+static int radix_tree_cpu_dead(unsigned int cpu)
 {
-	int cpu = (long)hcpu;
 	struct radix_tree_preload *rtp;
 	struct radix_tree_node *node;
 
 	/* Free per-cpu pool of preloaded nodes */
-	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
-		rtp = &per_cpu(radix_tree_preloads, cpu);
-		while (rtp->nr) {
-			node = rtp->nodes;
-			rtp->nodes = node->private_data;
-			kmem_cache_free(radix_tree_node_cachep, node);
-			rtp->nr--;
-		}
+	rtp = &per_cpu(radix_tree_preloads, cpu);
+	while (rtp->nr) {
+		node = rtp->nodes;
+		rtp->nodes = node->private_data;
+		kmem_cache_free(radix_tree_node_cachep, node);
+		rtp->nr--;
 	}
-	return NOTIFY_OK;
+	return 0;
 }
 
 void __init radix_tree_init(void)
 {
+	int ret;
 	radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
 			sizeof(struct radix_tree_node), 0,
 			SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
 			radix_tree_node_ctor);
 	radix_tree_init_maxnodes();
-	hotcpu_notifier(radix_tree_callback, 0);
+	ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead",
+					NULL, radix_tree_cpu_dead);
+	WARN_ON(ret < 0);
 }