Merge tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull CPU hotplug notifiers registration fixes from Rafael Wysocki:
 "The purpose of this single series of commits from Srivatsa S Bhat
  (with a small piece from Gautham R Shenoy) touching multiple
  subsystems that use CPU hotplug notifiers is to provide a way to
  register them that will not lead to deadlocks with CPU online/offline
  operations as described in the changelog of commit 93ae4f978ca7f ("CPU
  hotplug: Provide lockless versions of callback registration
  functions").

  The first three commits in the series introduce the API and document
  it and the rest simply goes through the users of CPU hotplug notifiers
  and converts them to using the new method"

* tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  net/iucv/iucv.c: Fix CPU hotplug callback registration
  net/core/flow.c: Fix CPU hotplug callback registration
  mm, zswap: Fix CPU hotplug callback registration
  mm, vmstat: Fix CPU hotplug callback registration
  profile: Fix CPU hotplug callback registration
  trace, ring-buffer: Fix CPU hotplug callback registration
  xen, balloon: Fix CPU hotplug callback registration
  hwmon, via-cputemp: Fix CPU hotplug callback registration
  hwmon, coretemp: Fix CPU hotplug callback registration
  thermal, x86-pkg-temp: Fix CPU hotplug callback registration
  octeon, watchdog: Fix CPU hotplug callback registration
  oprofile, nmi-timer: Fix CPU hotplug callback registration
  intel-idle: Fix CPU hotplug callback registration
  clocksource, dummy-timer: Fix CPU hotplug callback registration
  drivers/base/topology.c: Fix CPU hotplug callback registration
  acpi-cpufreq: Fix CPU hotplug callback registration
  zsmalloc: Fix CPU hotplug callback registration
  scsi, fcoe: Fix CPU hotplug callback registration
  scsi, bnx2fc: Fix CPU hotplug callback registration
  scsi, bnx2i: Fix CPU hotplug callback registration
  ...

3 files changed, 21 insertions, 10 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 197b4c4..302dd07 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1298,14 +1298,14 @@ static int __init setup_vmstat(void)
 #ifdef CONFIG_SMP
 	int cpu;
 
-	register_cpu_notifier(&vmstat_notifier);
+	cpu_notifier_register_begin();
+	__register_cpu_notifier(&vmstat_notifier);
 
-	get_online_cpus();
 	for_each_online_cpu(cpu) {
 		start_cpu_timer(cpu);
 		node_set_state(cpu_to_node(cpu), N_CPU);
 	}
-	put_online_cpus();
+	cpu_notifier_register_done();
 #endif
 #ifdef CONFIG_PROC_FS
 	proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index c03ca5e..36b4591 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -814,21 +814,32 @@ static void zs_exit(void)
 {
 	int cpu;
 
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(cpu)
 		zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu);
-	unregister_cpu_notifier(&zs_cpu_nb);
+	__unregister_cpu_notifier(&zs_cpu_nb);
+
+	cpu_notifier_register_done();
 }
 
 static int zs_init(void)
 {
 	int cpu, ret;
 
-	register_cpu_notifier(&zs_cpu_nb);
+	cpu_notifier_register_begin();
+
+	__register_cpu_notifier(&zs_cpu_nb);
 	for_each_online_cpu(cpu) {
 		ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
-		if (notifier_to_errno(ret))
+		if (notifier_to_errno(ret)) {
+			cpu_notifier_register_done();
 			goto fail;
+		}
 	}
+
+	cpu_notifier_register_done();
+
 	return 0;
 fail:
 	zs_exit();
diff --git a/mm/zswap.c b/mm/zswap.c
index e55bab9..d7337fb 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -387,18 +387,18 @@ static int zswap_cpu_init(void)
 {
 	unsigned long cpu;
 
-	get_online_cpus();
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu)
 		if (__zswap_cpu_notifier(CPU_UP_PREPARE, cpu) != NOTIFY_OK)
 			goto cleanup;
-	register_cpu_notifier(&zswap_cpu_notifier_block);
-	put_online_cpus();
+	__register_cpu_notifier(&zswap_cpu_notifier_block);
+	cpu_notifier_register_done();
 	return 0;
 
 cleanup:
 	for_each_online_cpu(cpu)
 		__zswap_cpu_notifier(CPU_UP_CANCELED, cpu);
-	put_online_cpus();
+	cpu_notifier_register_done();
 	return -ENOMEM;
 }