Merge branch 'akpm' (patches from Andrew Morton)

Merge misc fixes from Andrew Morton:
 "A few hotfixes and various leftovers which were awaiting other merges.

  Mainly movement of zram into mm/"

* emailed patches fron Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  memcg: fix mutex not unlocked on memcg_create_kmem_cache fail path
  Documentation/filesystems/vfs.txt: update file_operations documentation
  mm, oom: base root bonus on current usage
  mm: don't lose the SOFT_DIRTY flag on mprotect
  mm/slub.c: fix page->_count corruption (again)
  mm/mempolicy.c: fix mempolicy printing in numa_maps
  zram: remove zram->lock in read path and change it with mutex
  zram: remove workqueue for freeing removed pending slot
  zram: introduce zram->tb_lock
  zram: use atomic operation for stat
  zram: remove unnecessary free
  zram: delay pending free request in read path
  zram: fix race between reset and flushing pending work
  zsmalloc: add maintainers
  zram: add zram maintainers
  zsmalloc: add copyright
  zram: add copyright
  zram: remove old private project comment
  zram: promote zram from staging
  zsmalloc: move it under mm
  ...

1 files changed, 14 insertions, 54 deletions

diff --git a/kernel/smp.c b/kernel/smp.c
index bd9f94028838..ffee35bef179 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -23,17 +23,11 @@ enum {
 struct call_function_data {
 	struct call_single_data	__percpu *csd;
 	cpumask_var_t		cpumask;
-	cpumask_var_t		cpumask_ipi;
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
 
-struct call_single_queue {
-	struct list_head	list;
-	raw_spinlock_t		lock;
-};
-
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_queue, call_single_queue);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue);
 
 static int
 hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
@@ -47,14 +41,8 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
 				cpu_to_node(cpu)))
 			return notifier_from_errno(-ENOMEM);
-		if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL,
-				cpu_to_node(cpu))) {
-			free_cpumask_var(cfd->cpumask);
-			return notifier_from_errno(-ENOMEM);
-		}
 		cfd->csd = alloc_percpu(struct call_single_data);
 		if (!cfd->csd) {
-			free_cpumask_var(cfd->cpumask_ipi);
 			free_cpumask_var(cfd->cpumask);
 			return notifier_from_errno(-ENOMEM);
 		}
@@ -67,7 +55,6 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
 		free_cpumask_var(cfd->cpumask);
-		free_cpumask_var(cfd->cpumask_ipi);
 		free_percpu(cfd->csd);
 		break;
 #endif
@@ -85,12 +72,8 @@ void __init call_function_init(void)
 	void *cpu = (void *)(long)smp_processor_id();
 	int i;
 
-	for_each_possible_cpu(i) {
-		struct call_single_queue *q = &per_cpu(call_single_queue, i);
-
-		raw_spin_lock_init(&q->lock);
-		INIT_LIST_HEAD(&q->list);
-	}
+	for_each_possible_cpu(i)
+		init_llist_head(&per_cpu(call_single_queue, i));
 
 	hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
 	register_cpu_notifier(&hotplug_cfd_notifier);
@@ -141,18 +124,9 @@ static void csd_unlock(struct call_single_data *csd)
  */
 static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
 {
-	struct call_single_queue *dst = &per_cpu(call_single_queue, cpu);
-	unsigned long flags;
-	int ipi;
-
 	if (wait)
 		csd->flags |= CSD_FLAG_WAIT;
 
-	raw_spin_lock_irqsave(&dst->lock, flags);
-	ipi = list_empty(&dst->list);
-	list_add_tail(&csd->list, &dst->list);
-	raw_spin_unlock_irqrestore(&dst->lock, flags);
-
 	/*
 	 * The list addition should be visible before sending the IPI
 	 * handler locks the list to pull the entry off it because of
@@ -164,7 +138,7 @@ static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
 	 * locking and barrier primitives. Generic code isn't really
 	 * equipped to do the right thing...
 	 */
-	if (ipi)
+	if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)))
 		arch_send_call_function_single_ipi(cpu);
 
 	if (wait)
@@ -177,27 +151,26 @@ static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
  */
 void generic_smp_call_function_single_interrupt(void)
 {
-	struct call_single_queue *q = &__get_cpu_var(call_single_queue);
-	LIST_HEAD(list);
+	struct llist_node *entry, *next;
 
 	/*
 	 * Shouldn't receive this interrupt on a cpu that is not yet online.
 	 */
 	WARN_ON_ONCE(!cpu_online(smp_processor_id()));
 
-	raw_spin_lock(&q->lock);
-	list_replace_init(&q->list, &list);
-	raw_spin_unlock(&q->lock);
+	entry = llist_del_all(&__get_cpu_var(call_single_queue));
+	entry = llist_reverse_order(entry);
 
-	while (!list_empty(&list)) {
+	while (entry) {
 		struct call_single_data *csd;
 
-		csd = list_entry(list.next, struct call_single_data, list);
-		list_del(&csd->list);
+		next = entry->next;
 
+		csd = llist_entry(entry, struct call_single_data, llist);
 		csd->func(csd->info);
-
 		csd_unlock(csd);
+
+		entry = next;
 	}
 }
 
@@ -402,30 +375,17 @@ void smp_call_function_many(const struct cpumask *mask,
 	if (unlikely(!cpumask_weight(cfd->cpumask)))
 		return;
 
-	/*
-	 * After we put an entry into the list, cfd->cpumask may be cleared
-	 * again when another CPU sends another IPI for a SMP function call, so
-	 * cfd->cpumask will be zero.
-	 */
-	cpumask_copy(cfd->cpumask_ipi, cfd->cpumask);
-
 	for_each_cpu(cpu, cfd->cpumask) {
 		struct call_single_data *csd = per_cpu_ptr(cfd->csd, cpu);
-		struct call_single_queue *dst =
-					&per_cpu(call_single_queue, cpu);
-		unsigned long flags;
 
 		csd_lock(csd);
 		csd->func = func;
 		csd->info = info;
-
-		raw_spin_lock_irqsave(&dst->lock, flags);
-		list_add_tail(&csd->list, &dst->list);
-		raw_spin_unlock_irqrestore(&dst->lock, flags);
+		llist_add(&csd->llist, &per_cpu(call_single_queue, cpu));
 	}
 
 	/* Send a message to all CPUs in the map */
-	arch_send_call_function_ipi_mask(cfd->cpumask_ipi);
+	arch_send_call_function_ipi_mask(cfd->cpumask);
 
 	if (wait) {
 		for_each_cpu(cpu, cfd->cpumask) {