[tip:smp/hotplug] lib/radix-tree: Convert to hotplug state machine

[tip-bot for Sebastian Andrzej Siewior]

Commit-ID:  d544abd5ff7d8b07c0c67682a63e4939c3c82914
Gitweb:     http://git.kernel.org/tip/d544abd5ff7d8b07c0c67682a63e4939c3c82914
Author:     Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Thu, 3 Nov 2016 15:50:01 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 9 Nov 2016 23:45:27 +0100

lib/radix-tree: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: rt@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20161103145021.28528-6-bigeasy@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 include/linux/cpuhotplug.h |  1 +
 lib/radix-tree.c           | 25 ++++++++++++-------------
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 04e5f99..89310fb 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -34,6 +34,7 @@ enum cpuhp_state {
 	CPUHP_PRINTK_DEAD,
 	CPUHP_MM_MEMCQ_DEAD,
 	CPUHP_PERCPU_CNT_DEAD,
+	CPUHP_RADIX_DEAD,
 	CPUHP_WORKQUEUE_PREP,
 	CPUHP_POWER_NUMA_PREPARE,
 	CPUHP_HRTIMERS_PREPARE,
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8e6d552..4b8bb36 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);
 }