Merge tag 'v3.7-rc1' into staging/for_v3.8

Linux 3.7-rc1

* tag 'v3.7-rc1': (9579 commits)
  Linux 3.7-rc1
  x86, boot: Explicitly include autoconf.h for hostprogs
  perf: Fix UAPI fallout
  ARM: config: make sure that platforms are ordered by option string
  ARM: config: sort select statements alphanumerically
  UAPI: (Scripted) Disintegrate include/linux/byteorder
  UAPI: (Scripted) Disintegrate include/linux
  UAPI: Unexport linux/blk_types.h
  UAPI: Unexport part of linux/ppp-comp.h
  perf: Handle new rbtree implementation
  procfs: don't need a PATH_MAX allocation to hold a string representation of an int
  vfs: embed struct filename inside of names_cache allocation if possible
  audit: make audit_inode take struct filename
  vfs: make path_openat take a struct filename pointer
  vfs: turn do_path_lookup into wrapper around struct filename variant
  audit: allow audit code to satisfy getname requests from its names_list
  vfs: define struct filename and have getname() return it
  btrfs: Fix compilation with user namespace support enabled
  userns: Fix posix_acl_file_xattr_userns gid conversion
  userns: Properly print bluetooth socket uids
  ...

1 files changed, 13 insertions, 12 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 14d32588ccc..42bd331ee0a 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -80,6 +80,10 @@ void put_online_cpus(void)
 	if (cpu_hotplug.active_writer == current)
 		return;
 	mutex_lock(&cpu_hotplug.lock);
+
+	if (WARN_ON(!cpu_hotplug.refcount))
+		cpu_hotplug.refcount++; /* try to fix things up */
+
 	if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
 		wake_up_process(cpu_hotplug.active_writer);
 	mutex_unlock(&cpu_hotplug.lock);
@@ -280,12 +284,13 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 				__func__, cpu);
 		goto out_release;
 	}
+	smpboot_park_threads(cpu);
 
 	err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
 	if (err) {
 		/* CPU didn't die: tell everyone.  Can't complain. */
+		smpboot_unpark_threads(cpu);
 		cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
-
 		goto out_release;
 	}
 	BUG_ON(cpu_online(cpu));
@@ -354,6 +359,10 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
 		goto out;
 	}
 
+	ret = smpboot_create_threads(cpu);
+	if (ret)
+		goto out;
+
 	ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
 	if (ret) {
 		nr_calls--;
@@ -368,6 +377,9 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
 		goto out_notify;
 	BUG_ON(!cpu_online(cpu));
 
+	/* Wake the per cpu threads */
+	smpboot_unpark_threads(cpu);
+
 	/* Now call notifier in preparation. */
 	cpu_notify(CPU_ONLINE | mod, hcpu);
 
@@ -439,14 +451,6 @@ EXPORT_SYMBOL_GPL(cpu_up);
 #ifdef CONFIG_PM_SLEEP_SMP
 static cpumask_var_t frozen_cpus;
 
-void __weak arch_disable_nonboot_cpus_begin(void)
-{
-}
-
-void __weak arch_disable_nonboot_cpus_end(void)
-{
-}
-
 int disable_nonboot_cpus(void)
 {
 	int cpu, first_cpu, error = 0;
@@ -458,7 +462,6 @@ int disable_nonboot_cpus(void)
 	 * with the userspace trying to use the CPU hotplug at the same time
 	 */
 	cpumask_clear(frozen_cpus);
-	arch_disable_nonboot_cpus_begin();
 
 	printk("Disabling non-boot CPUs ...\n");
 	for_each_online_cpu(cpu) {
@@ -474,8 +477,6 @@ int disable_nonboot_cpus(void)
 		}
 	}
 
-	arch_disable_nonboot_cpus_end();
-
 	if (!error) {
 		BUG_ON(num_online_cpus() > 1);
 		/* Make sure the CPUs won't be enabled by someone else */