24 files changed, 1029 insertions, 85 deletions
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index 08561f1acd13..ebdb0043203a 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -235,9 +235,16 @@ config LOCK_SPIN_ON_OWNER
        def_bool y
        depends on MUTEX_SPIN_ON_OWNER || RWSEM_SPIN_ON_OWNER
 
-config ARCH_USE_QUEUE_RWLOCK
+config ARCH_USE_QUEUED_SPINLOCKS
 	bool
 
-config QUEUE_RWLOCK
-	def_bool y if ARCH_USE_QUEUE_RWLOCK
+config QUEUED_SPINLOCKS
+	def_bool y if ARCH_USE_QUEUED_SPINLOCKS
+	depends on SMP
+
+config ARCH_USE_QUEUED_RWLOCKS
+	bool
+
+config QUEUED_RWLOCKS
+	def_bool y if ARCH_USE_QUEUED_RWLOCKS
 	depends on SMP
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 81aa3a4ece9f..1a3bf48743ce 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -913,10 +913,30 @@ static void put_ctx(struct perf_event_context *ctx)
  * Those places that change perf_event::ctx will hold both
  * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
  *
- * Lock ordering is by mutex address. There is one other site where
- * perf_event_context::mutex nests and that is put_event(). But remember that
- * that is a parent<->child context relation, and migration does not affect
- * children, therefore these two orderings should not interact.
+ * Lock ordering is by mutex address. There are two other sites where
+ * perf_event_context::mutex nests and those are:
+ *
+ *  - perf_event_exit_task_context()	[ child , 0 ]
+ *      __perf_event_exit_task()
+ *        sync_child_event()
+ *          put_event()			[ parent, 1 ]
+ *
+ *  - perf_event_init_context()		[ parent, 0 ]
+ *      inherit_task_group()
+ *        inherit_group()
+ *          inherit_event()
+ *            perf_event_alloc()
+ *              perf_init_event()
+ *                perf_try_init_event()	[ child , 1 ]
+ *
+ * While it appears there is an obvious deadlock here -- the parent and child
+ * nesting levels are inverted between the two. This is in fact safe because
+ * life-time rules separate them. That is an exiting task cannot fork, and a
+ * spawning task cannot (yet) exit.
+ *
+ * But remember that that these are parent<->child context relations, and
+ * migration does not affect children, therefore these two orderings should not
+ * interact.
  *
  * The change in perf_event::ctx does not affect children (as claimed above)
  * because the sys_perf_event_open() case will install a new event and break
@@ -3657,9 +3677,6 @@ static void perf_remove_from_owner(struct perf_event *event)
 	}
 }
 
-/*
- * Called when the last reference to the file is gone.
- */
 static void put_event(struct perf_event *event)
 {
 	struct perf_event_context *ctx;
@@ -3697,6 +3714,9 @@ int perf_event_release_kernel(struct perf_event *event)
 }
 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
 
+/*
+ * Called when the last reference to the file is gone.
+ */
 static int perf_release(struct inode *inode, struct file *file)
 {
 	put_event(file->private_data);
@@ -7364,7 +7384,12 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
 		return -ENODEV;
 
 	if (event->group_leader != event) {
-		ctx = perf_event_ctx_lock(event->group_leader);
+		/*
+		 * This ctx->mutex can nest when we're called through
+		 * inheritance. See the perf_event_ctx_lock_nested() comment.
+		 */
+		ctx = perf_event_ctx_lock_nested(event->group_leader,
+						 SINGLE_DEPTH_NESTING);
 		BUG_ON(!ctx);
 	}
 
diff --git a/kernel/futex.c b/kernel/futex.c
index 2579e407ff67..55ca63ad9622 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2055,7 +2055,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
 {
 	/*
 	 * The task state is guaranteed to be set before another task can
-	 * wake it. set_current_state() is implemented using set_mb() and
+	 * wake it. set_current_state() is implemented using smp_store_mb() and
 	 * queue_me() calls spin_unlock() upon completion, both serializing
 	 * access to the hash list and forcing another memory barrier.
 	 */
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index eb9a4ea394ab..55016b2151f3 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -950,6 +950,20 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data)
 }
 
 /**
+ * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt
+ * @data:	Pointer to interrupt specific data
+ * @dest:	The vcpu affinity information
+ */
+int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info)
+{
+	data = data->parent_data;
+	if (data->chip->irq_set_vcpu_affinity)
+		return data->chip->irq_set_vcpu_affinity(data, vcpu_info);
+
+	return -ENOSYS;
+}
+
+/**
  * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt
  * @data:	Pointer to interrupt specific data
  * @on:		Whether to set or reset the wake-up capability of this irq
diff --git a/kernel/irq/dummychip.c b/kernel/irq/dummychip.c
index 988dc58e8847..2feb6feca0cc 100644
--- a/kernel/irq/dummychip.c
+++ b/kernel/irq/dummychip.c
@@ -57,5 +57,6 @@ struct irq_chip dummy_irq_chip = {
 	.irq_ack	= noop,
 	.irq_mask	= noop,
 	.irq_unmask	= noop,
+	.flags		= IRQCHIP_SKIP_SET_WAKE,
 };
 EXPORT_SYMBOL_GPL(dummy_irq_chip);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index df553b0af936..b93d434e70bd 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -59,8 +59,6 @@ enum {
 #include "debug.h"
 #include "settings.h"
 
-#define irq_data_to_desc(data)	container_of(data, struct irq_desc, irq_data)
-
 extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
 		unsigned long flags);
 extern void __disable_irq(struct irq_desc *desc, unsigned int irq);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e68932bb308e..b1c7e8f46bfb 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -256,6 +256,37 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
 }
 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
 
+/**
+ *	irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
+ *	@irq: interrupt number to set affinity
+ *	@vcpu_info: vCPU specific data
+ *
+ *	This function uses the vCPU specific data to set the vCPU
+ *	affinity for an irq. The vCPU specific data is passed from
+ *	outside, such as KVM. One example code path is as below:
+ *	KVM -> IOMMU -> irq_set_vcpu_affinity().
+ */
+int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
+{
+	unsigned long flags;
+	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
+	struct irq_data *data;
+	struct irq_chip *chip;
+	int ret = -ENOSYS;
+
+	if (!desc)
+		return -EINVAL;
+
+	data = irq_desc_get_irq_data(desc);
+	chip = irq_data_get_irq_chip(data);
+	if (chip && chip->irq_set_vcpu_affinity)
+		ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
+	irq_put_desc_unlock(desc, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
+
 static void irq_affinity_notify(struct work_struct *work)
 {
 	struct irq_affinity_notify *notify =
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index ca3f4aaff707..dd203e276b07 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -7,7 +7,7 @@
 void irq_move_masked_irq(struct irq_data *idata)
 {
 	struct irq_desc *desc = irq_data_to_desc(idata);
-	struct irq_chip *chip = idata->chip;
+	struct irq_chip *chip = desc->irq_data.chip;
 
 	if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
 		return;
@@ -52,6 +52,13 @@ void irq_move_irq(struct irq_data *idata)
 {
 	bool masked;
 
+	/*
+	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
+	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
+	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
+	 */
+	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
+
 	if (likely(!irqd_is_setaffinity_pending(idata)))
 		return;
 
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index de7a416cca2a..7dd5c9918e4c 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_SMP) += spinlock.o
 obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o
 obj-$(CONFIG_SMP) += lglock.o
 obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
+obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o
 obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
 obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
 obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
@@ -25,5 +26,5 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
 obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
-obj-$(CONFIG_QUEUE_RWLOCK) += qrwlock.o
+obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o
 obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index a0831e1b99f4..a61bb1d37a52 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4066,8 +4066,7 @@ void __init lockdep_info(void)
 
 #ifdef CONFIG_DEBUG_LOCKDEP
 	if (lockdep_init_error) {
-		printk("WARNING: lockdep init error! lock-%s was acquired"
-			"before lockdep_init\n", lock_init_error);
+		printk("WARNING: lockdep init error: lock '%s' was acquired before lockdep_init().\n", lock_init_error);
 		printk("Call stack leading to lockdep invocation was:\n");
 		print_stack_trace(&lockdep_init_trace, 0);
 	}
diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index 75e114bdf3f2..fd91aaa4554c 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/kernel/locking/mcs_spinlock.h
@@ -17,6 +17,7 @@
 struct mcs_spinlock {
 	struct mcs_spinlock *next;
 	int locked; /* 1 if lock acquired */
+	int count;  /* nesting count, see qspinlock.c */
 };
 
 #ifndef arch_mcs_spin_lock_contended
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index f956ede7f90d..00c12bb390b5 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -1,5 +1,5 @@
 /*
- * Queue read/write lock
+ * Queued read/write locks
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
new file mode 100644
index 000000000000..38c49202d532
--- /dev/null
+++ b/kernel/locking/qspinlock.c
@@ -0,0 +1,473 @@
+/*
+ * Queued spinlock
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.
+ * (C) Copyright 2013-2014 Red Hat, Inc.
+ * (C) Copyright 2015 Intel Corp.
+ *
+ * Authors: Waiman Long <waiman.long@hp.com>
+ *          Peter Zijlstra <peterz@infradead.org>
+ */
+
+#ifndef _GEN_PV_LOCK_SLOWPATH
+
+#include <linux/smp.h>
+#include <linux/bug.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/mutex.h>
+#include <asm/byteorder.h>
+#include <asm/qspinlock.h>
+
+/*
+ * The basic principle of a queue-based spinlock can best be understood
+ * by studying a classic queue-based spinlock implementation called the
+ * MCS lock. The paper below provides a good description for this kind
+ * of lock.
+ *
+ * http://www.cise.ufl.edu/tr/DOC/REP-1992-71.pdf
+ *
+ * This queued spinlock implementation is based on the MCS lock, however to make
+ * it fit the 4 bytes we assume spinlock_t to be, and preserve its existing
+ * API, we must modify it somehow.
+ *
+ * In particular; where the traditional MCS lock consists of a tail pointer
+ * (8 bytes) and needs the next pointer (another 8 bytes) of its own node to
+ * unlock the next pending (next->locked), we compress both these: {tail,
+ * next->locked} into a single u32 value.
+ *
+ * Since a spinlock disables recursion of its own context and there is a limit
+ * to the contexts that can nest; namely: task, softirq, hardirq, nmi. As there
+ * are at most 4 nesting levels, it can be encoded by a 2-bit number. Now
+ * we can encode the tail by combining the 2-bit nesting level with the cpu
+ * number. With one byte for the lock value and 3 bytes for the tail, only a
+ * 32-bit word is now needed. Even though we only need 1 bit for the lock,
+ * we extend it to a full byte to achieve better performance for architectures
+ * that support atomic byte write.
+ *
+ * We also change the first spinner to spin on the lock bit instead of its
+ * node; whereby avoiding the need to carry a node from lock to unlock, and
+ * preserving existing lock API. This also makes the unlock code simpler and
+ * faster.
+ *
+ * N.B. The current implementation only supports architectures that allow
+ *      atomic operations on smaller 8-bit and 16-bit data types.
+ *
+ */
+
+#include "mcs_spinlock.h"
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define MAX_NODES	8
+#else
+#define MAX_NODES	4
+#endif
+
+/*
+ * Per-CPU queue node structures; we can never have more than 4 nested
+ * contexts: task, softirq, hardirq, nmi.
+ *
+ * Exactly fits one 64-byte cacheline on a 64-bit architecture.
+ *
+ * PV doubles the storage and uses the second cacheline for PV state.
+ */
+static DEFINE_PER_CPU_ALIGNED(struct mcs_spinlock, mcs_nodes[MAX_NODES]);
+
+/*
+ * We must be able to distinguish between no-tail and the tail at 0:0,
+ * therefore increment the cpu number by one.
+ */
+
+static inline u32 encode_tail(int cpu, int idx)
+{
+	u32 tail;
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+	BUG_ON(idx > 3);
+#endif
+	tail  = (cpu + 1) << _Q_TAIL_CPU_OFFSET;
+	tail |= idx << _Q_TAIL_IDX_OFFSET; /* assume < 4 */
+
+	return tail;
+}
+
+static inline struct mcs_spinlock *decode_tail(u32 tail)
+{
+	int cpu = (tail >> _Q_TAIL_CPU_OFFSET) - 1;
+	int idx = (tail &  _Q_TAIL_IDX_MASK) >> _Q_TAIL_IDX_OFFSET;
+
+	return per_cpu_ptr(&mcs_nodes[idx], cpu);
+}
+
+#define _Q_LOCKED_PENDING_MASK (_Q_LOCKED_MASK | _Q_PENDING_MASK)
+
+/*
+ * By using the whole 2nd least significant byte for the pending bit, we
+ * can allow better optimization of the lock acquisition for the pending
+ * bit holder.
+ *
+ * This internal structure is also used by the set_locked function which
+ * is not restricted to _Q_PENDING_BITS == 8.
+ */
+struct __qspinlock {
+	union {
+		atomic_t val;
+#ifdef __LITTLE_ENDIAN
+		struct {
+			u8	locked;
+			u8	pending;
+		};
+		struct {
+			u16	locked_pending;
+			u16	tail;
+		};
+#else
+		struct {
+			u16	tail;
+			u16	locked_pending;
+		};
+		struct {
+			u8	reserved[2];
+			u8	pending;
+			u8	locked;
+		};
+#endif
+	};
+};
+
+#if _Q_PENDING_BITS == 8
+/**
+ * clear_pending_set_locked - take ownership and clear the pending bit.
+ * @lock: Pointer to queued spinlock structure
+ *
+ * *,1,0 -> *,0,1
+ *
+ * Lock stealing is not allowed if this function is used.
+ */
+static __always_inline void clear_pending_set_locked(struct qspinlock *lock)
+{
+	struct __qspinlock *l = (void *)lock;
+
+	WRITE_ONCE(l->locked_pending, _Q_LOCKED_VAL);
+}
+
+/*
+ * xchg_tail - Put in the new queue tail code word & retrieve previous one
+ * @lock : Pointer to queued spinlock structure
+ * @tail : The new queue tail code word
+ * Return: The previous queue tail code word
+ *
+ * xchg(lock, tail)
+ *
+ * p,*,* -> n,*,* ; prev = xchg(lock, node)
+ */
+static __always_inline u32 xchg_tail(struct qspinlock *lock, u32 tail)
+{
+	struct __qspinlock *l = (void *)lock;
+
+	return (u32)xchg(&l->tail, tail >> _Q_TAIL_OFFSET) << _Q_TAIL_OFFSET;
+}
+
+#else /* _Q_PENDING_BITS == 8 */
+
+/**
+ * clear_pending_set_locked - take ownership and clear the pending bit.
+ * @lock: Pointer to queued spinlock structure
+ *
+ * *,1,0 -> *,0,1
+ */
+static __always_inline void clear_pending_set_locked(struct qspinlock *lock)
+{
+	atomic_add(-_Q_PENDING_VAL + _Q_LOCKED_VAL, &lock->val);
+}
+
+/**
+ * xchg_tail - Put in the new queue tail code word & retrieve previous one
+ * @lock : Pointer to queued spinlock structure
+ * @tail : The new queue tail code word
+ * Return: The previous queue tail code word
+ *
+ * xchg(lock, tail)
+ *
+ * p,*,* -> n,*,* ; prev = xchg(lock, node)
+ */
+static __always_inline u32 xchg_tail(struct qspinlock *lock, u32 tail)
+{
+	u32 old, new, val = atomic_read(&lock->val);
+
+	for (;;) {
+		new = (val & _Q_LOCKED_PENDING_MASK) | tail;
+		old = atomic_cmpxchg(&lock->val, val, new);
+		if (old == val)
+			break;
+
+		val = old;
+	}
+	return old;
+}
+#endif /* _Q_PENDING_BITS == 8 */
+
+/**
+ * set_locked - Set the lock bit and own the lock
+ * @lock: Pointer to queued spinlock structure
+ *
+ * *,*,0 -> *,0,1
+ */
+static __always_inline void set_locked(struct qspinlock *lock)
+{
+	struct __qspinlock *l = (void *)lock;
+
+	WRITE_ONCE(l->locked, _Q_LOCKED_VAL);
+}
+
+
+/*
+ * Generate the native code for queued_spin_unlock_slowpath(); provide NOPs for
+ * all the PV callbacks.
+ */
+
+static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
+
+static __always_inline void __pv_wait_head(struct qspinlock *lock,
+					   struct mcs_spinlock *node) { }
+
+#define pv_enabled()		false
+
+#define pv_init_node		__pv_init_node
+#define pv_wait_node		__pv_wait_node
+#define pv_kick_node		__pv_kick_node
+#define pv_wait_head		__pv_wait_head
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define queued_spin_lock_slowpath	native_queued_spin_lock_slowpath
+#endif
+
+#endif /* _GEN_PV_LOCK_SLOWPATH */
+
+/**
+ * queued_spin_lock_slowpath - acquire the queued spinlock
+ * @lock: Pointer to queued spinlock structure
+ * @val: Current value of the queued spinlock 32-bit word
+ *
+ * (queue tail, pending bit, lock value)
+ *
+ *              fast     :    slow                                  :    unlock
+ *                       :                                          :
+ * uncontended  (0,0,0) -:--> (0,0,1) ------------------------------:--> (*,*,0)
+ *                       :       | ^--------.------.             /  :
+ *                       :       v           \      \            |  :
+ * pending               :    (0,1,1) +--> (0,1,0)   \           |  :
+ *                       :       | ^--'              |           |  :
+ *                       :       v                   |           |  :
+ * uncontended           :    (n,x,y) +--> (n,0,0) --'           |  :
+ *   queue               :       | ^--'                          |  :
+ *                       :       v                               |  :
+ * contended             :    (*,x,y) +--> (*,0,0) ---> (*,0,1) -'  :
+ *   queue               :         ^--'                             :
+ */
+void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+{
+	struct mcs_spinlock *prev, *next, *node;
+	u32 new, old, tail;
+	int idx;
+
+	BUILD_BUG_ON(CONFIG_NR_CPUS >= (1U << _Q_TAIL_CPU_BITS));
+
+	if (pv_enabled())
+		goto queue;
+
+	if (virt_queued_spin_lock(lock))
+		return;
+
+	/*
+	 * wait for in-progress pending->locked hand-overs
+	 *
+	 * 0,1,0 -> 0,0,1
+	 */
+	if (val == _Q_PENDING_VAL) {
+		while ((val = atomic_read(&lock->val)) == _Q_PENDING_VAL)
+			cpu_relax();
+	}
+
+	/*
+	 * trylock || pending
+	 *
+	 * 0,0,0 -> 0,0,1 ; trylock
+	 * 0,0,1 -> 0,1,1 ; pending
+	 */
+	for (;;) {
+		/*
+		 * If we observe any contention; queue.
+		 */
+		if (val & ~_Q_LOCKED_MASK)
+			goto queue;
+
+		new = _Q_LOCKED_VAL;
+		if (val == new)
+			new |= _Q_PENDING_VAL;
+
+		old = atomic_cmpxchg(&lock->val, val, new);
+		if (old == val)
+			break;
+
+		val = old;
+	}
+
+	/*
+	 * we won the trylock
+	 */
+	if (new == _Q_LOCKED_VAL)
+		return;
+
+	/*
+	 * we're pending, wait for the owner to go away.
+	 *
+	 * *,1,1 -> *,1,0
+	 *
+	 * this wait loop must be a load-acquire such that we match the
+	 * store-release that clears the locked bit and create lock
+	 * sequentiality; this is because not all clear_pending_set_locked()
+	 * implementations imply full barriers.
+	 */
+	while ((val = smp_load_acquire(&lock->val.counter)) & _Q_LOCKED_MASK)
+		cpu_relax();
+
+	/*
+	 * take ownership and clear the pending bit.
+	 *
+	 * *,1,0 -> *,0,1
+	 */
+	clear_pending_set_locked(lock);
+	return;
+
+	/*
+	 * End of pending bit optimistic spinning and beginning of MCS
+	 * queuing.
+	 */
+queue:
+	node = this_cpu_ptr(&mcs_nodes[0]);
+	idx = node->count++;
+	tail = encode_tail(smp_processor_id(), idx);
+
+	node += idx;
+	node->locked = 0;
+	node->next = NULL;
+	pv_init_node(node);
+
+	/*
+	 * We touched a (possibly) cold cacheline in the per-cpu queue node;
+	 * attempt the trylock once more in the hope someone let go while we
+	 * weren't watching.
+	 */
+	if (queued_spin_trylock(lock))
+		goto release;
+
+	/*
+	 * We have already touched the queueing cacheline; don't bother with
+	 * pending stuff.
+	 *
+	 * p,*,* -> n,*,*
+	 */
+	old = xchg_tail(lock, tail);
+
+	/*
+	 * if there was a previous node; link it and wait until reaching the
+	 * head of the waitqueue.
+	 */
+	if (old & _Q_TAIL_MASK) {
+		prev = decode_tail(old);
+		WRITE_ONCE(prev->next, node);
+
+		pv_wait_node(node);
+		arch_mcs_spin_lock_contended(&node->locked);
+	}
+
+	/*
+	 * we're at the head of the waitqueue, wait for the owner & pending to
+	 * go away.
+	 *
+	 * *,x,y -> *,0,0
+	 *
+	 * this wait loop must use a load-acquire such that we match the
+	 * store-release that clears the locked bit and create lock
+	 * sequentiality; this is because the set_locked() function below
+	 * does not imply a full barrier.
+	 *
+	 */
+	pv_wait_head(lock, node);
+	while ((val = smp_load_acquire(&lock->val.counter)) & _Q_LOCKED_PENDING_MASK)
+		cpu_relax();
+
+	/*
+	 * claim the lock:
+	 *
+	 * n,0,0 -> 0,0,1 : lock, uncontended
+	 * *,0,0 -> *,0,1 : lock, contended
+	 *
+	 * If the queue head is the only one in the queue (lock value == tail),
+	 * clear the tail code and grab the lock. Otherwise, we only need
+	 * to grab the lock.
+	 */
+	for (;;) {
+		if (val != tail) {
+			set_locked(lock);
+			break;
+		}
+		old = atomic_cmpxchg(&lock->val, val, _Q_LOCKED_VAL);
+		if (old == val)
+			goto release;	/* No contention */
+
+		val = old;
+	}
+
+	/*
+	 * contended path; wait for next, release.
+	 */
+	while (!(next = READ_ONCE(node->next)))
+		cpu_relax();
+
+	arch_mcs_spin_unlock_contended(&next->locked);
+	pv_kick_node(next);
+
+release:
+	/*
+	 * release the node
+	 */
+	this_cpu_dec(mcs_nodes[0].count);
+}
+EXPORT_SYMBOL(queued_spin_lock_slowpath);
+
+/*
+ * Generate the paravirt code for queued_spin_unlock_slowpath().
+ */
+#if !defined(_GEN_PV_LOCK_SLOWPATH) && defined(CONFIG_PARAVIRT_SPINLOCKS)
+#define _GEN_PV_LOCK_SLOWPATH
+
+#undef  pv_enabled
+#define pv_enabled()	true
+
+#undef pv_init_node
+#undef pv_wait_node
+#undef pv_kick_node
+#undef pv_wait_head
+
+#undef  queued_spin_lock_slowpath
+#define queued_spin_lock_slowpath	__pv_queued_spin_lock_slowpath
+
+#include "qspinlock_paravirt.h"
+#include "qspinlock.c"
+
+#endif
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
new file mode 100644
index 000000000000..04ab18151cc8
--- /dev/null
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -0,0 +1,325 @@
+#ifndef _GEN_PV_LOCK_SLOWPATH
+#error "do not include this file"
+#endif
+
+#include <linux/hash.h>
+#include <linux/bootmem.h>
+
+/*
+ * Implement paravirt qspinlocks; the general idea is to halt the vcpus instead
+ * of spinning them.
+ *
+ * This relies on the architecture to provide two paravirt hypercalls:
+ *
+ *   pv_wait(u8 *ptr, u8 val) -- suspends the vcpu if *ptr == val
+ *   pv_kick(cpu)             -- wakes a suspended vcpu
+ *
+ * Using these we implement __pv_queued_spin_lock_slowpath() and
+ * __pv_queued_spin_unlock() to replace native_queued_spin_lock_slowpath() and
+ * native_queued_spin_unlock().
+ */
+
+#define _Q_SLOW_VAL	(3U << _Q_LOCKED_OFFSET)
+
+enum vcpu_state {
+	vcpu_running = 0,
+	vcpu_halted,
+};
+
+struct pv_node {
+	struct mcs_spinlock	mcs;
+	struct mcs_spinlock	__res[3];
+
+	int			cpu;
+	u8			state;
+};
+
+/*
+ * Lock and MCS node addresses hash table for fast lookup
+ *
+ * Hashing is done on a per-cacheline basis to minimize the need to access
+ * more than one cacheline.
+ *
+ * Dynamically allocate a hash table big enough to hold at least 4X the
+ * number of possible cpus in the system. Allocation is done on page
+ * granularity. So the minimum number of hash buckets should be at least
+ * 256 (64-bit) or 512 (32-bit) to fully utilize a 4k page.
+ *
+ * Since we should not be holding locks from NMI context (very rare indeed) the
+ * max load factor is 0.75, which is around the point where open addressing
+ * breaks down.
+ *
+ */
+struct pv_hash_entry {
+	struct qspinlock *lock;
+	struct pv_node   *node;
+};
+
+#define PV_HE_PER_LINE	(SMP_CACHE_BYTES / sizeof(struct pv_hash_entry))
+#define PV_HE_MIN	(PAGE_SIZE / sizeof(struct pv_hash_entry))
+
+static struct pv_hash_entry *pv_lock_hash;
+static unsigned int pv_lock_hash_bits __read_mostly;
+
+/*
+ * Allocate memory for the PV qspinlock hash buckets
+ *
+ * This function should be called from the paravirt spinlock initialization
+ * routine.
+ */
+void __init __pv_init_lock_hash(void)
+{
+	int pv_hash_size = ALIGN(4 * num_possible_cpus(), PV_HE_PER_LINE);
+
+	if (pv_hash_size < PV_HE_MIN)
+		pv_hash_size = PV_HE_MIN;
+
+	/*
+	 * Allocate space from bootmem which should be page-size aligned
+	 * and hence cacheline aligned.
+	 */
+	pv_lock_hash = alloc_large_system_hash("PV qspinlock",
+					       sizeof(struct pv_hash_entry),
+					       pv_hash_size, 0, HASH_EARLY,
+					       &pv_lock_hash_bits, NULL,
+					       pv_hash_size, pv_hash_size);
+}
+
+#define for_each_hash_entry(he, offset, hash)						\
+	for (hash &= ~(PV_HE_PER_LINE - 1), he = &pv_lock_hash[hash], offset = 0;	\
+	     offset < (1 << pv_lock_hash_bits);						\
+	     offset++, he = &pv_lock_hash[(hash + offset) & ((1 << pv_lock_hash_bits) - 1)])
+
+static struct qspinlock **pv_hash(struct qspinlock *lock, struct pv_node *node)
+{
+	unsigned long offset, hash = hash_ptr(lock, pv_lock_hash_bits);
+	struct pv_hash_entry *he;
+
+	for_each_hash_entry(he, offset, hash) {
+		if (!cmpxchg(&he->lock, NULL, lock)) {
+			WRITE_ONCE(he->node, node);
+			return &he->lock;
+		}
+	}
+	/*
+	 * Hard assume there is a free entry for us.
+	 *
+	 * This is guaranteed by ensuring every blocked lock only ever consumes
+	 * a single entry, and since we only have 4 nesting levels per CPU
+	 * and allocated 4*nr_possible_cpus(), this must be so.
+	 *
+	 * The single entry is guaranteed by having the lock owner unhash
+	 * before it releases.
+	 */
+	BUG();
+}
+
+static struct pv_node *pv_unhash(struct qspinlock *lock)
+{
+	unsigned long offset, hash = hash_ptr(lock, pv_lock_hash_bits);
+	struct pv_hash_entry *he;
+	struct pv_node *node;
+
+	for_each_hash_entry(he, offset, hash) {
+		if (READ_ONCE(he->lock) == lock) {
+			node = READ_ONCE(he->node);
+			WRITE_ONCE(he->lock, NULL);
+			return node;
+		}
+	}
+	/*
+	 * Hard assume we'll find an entry.
+	 *
+	 * This guarantees a limited lookup time and is itself guaranteed by
+	 * having the lock owner do the unhash -- IFF the unlock sees the
+	 * SLOW flag, there MUST be a hash entry.
+	 */
+	BUG();
+}
+
+/*
+ * Initialize the PV part of the mcs_spinlock node.
+ */
+static void pv_init_node(struct mcs_spinlock *node)
+{
+	struct pv_node *pn = (struct pv_node *)node;
+
+	BUILD_BUG_ON(sizeof(struct pv_node) > 5*sizeof(struct mcs_spinlock));
+
+	pn->cpu = smp_processor_id();
+	pn->state = vcpu_running;
+}
+
+/*
+ * Wait for node->locked to become true, halt the vcpu after a short spin.
+ * pv_kick_node() is used to wake the vcpu again.
+ */
+static void pv_wait_node(struct mcs_spinlock *node)
+{
+	struct pv_node *pn = (struct pv_node *)node;
+	int loop;
+
+	for (;;) {
+		for (loop = SPIN_THRESHOLD; loop; loop--) {
+			if (READ_ONCE(node->locked))
+				return;
+			cpu_relax();
+		}
+
+		/*
+		 * Order pn->state vs pn->locked thusly:
+		 *
+		 * [S] pn->state = vcpu_halted	  [S] next->locked = 1
+		 *     MB			      MB
+		 * [L] pn->locked		[RmW] pn->state = vcpu_running
+		 *
+		 * Matches the xchg() from pv_kick_node().
+		 */
+		smp_store_mb(pn->state, vcpu_halted);
+
+		if (!READ_ONCE(node->locked))
+			pv_wait(&pn->state, vcpu_halted);
+
+		/*
+		 * Reset the vCPU state to avoid unncessary CPU kicking
+		 */
+		WRITE_ONCE(pn->state, vcpu_running);
+
+		/*
+		 * If the locked flag is still not set after wakeup, it is a
+		 * spurious wakeup and the vCPU should wait again. However,
+		 * there is a pretty high overhead for CPU halting and kicking.
+		 * So it is better to spin for a while in the hope that the
+		 * MCS lock will be released soon.
+		 */
+	}
+	/*
+	 * By now our node->locked should be 1 and our caller will not actually
+	 * spin-wait for it. We do however rely on our caller to do a
+	 * load-acquire for us.
+	 */
+}
+
+/*
+ * Called after setting next->locked = 1, used to wake those stuck in
+ * pv_wait_node().
+ */
+static void pv_kick_node(struct mcs_spinlock *node)
+{
+	struct pv_node *pn = (struct pv_node *)node;
+
+	/*
+	 * Note that because node->locked is already set, this actual
+	 * mcs_spinlock entry could be re-used already.
+	 *
+	 * This should be fine however, kicking people for no reason is
+	 * harmless.
+	 *
+	 * See the comment in pv_wait_node().
+	 */
+	if (xchg(&pn->state, vcpu_running) == vcpu_halted)
+		pv_kick(pn->cpu);
+}
+
+/*
+ * Wait for l->locked to become clear; halt the vcpu after a short spin.
+ * __pv_queued_spin_unlock() will wake us.
+ */
+static void pv_wait_head(struct qspinlock *lock, struct mcs_spinlock *node)
+{
+	struct pv_node *pn = (struct pv_node *)node;
+	struct __qspinlock *l = (void *)lock;
+	struct qspinlock **lp = NULL;
+	int loop;
+
+	for (;;) {
+		for (loop = SPIN_THRESHOLD; loop; loop--) {
+			if (!READ_ONCE(l->locked))
+				return;
+			cpu_relax();
+		}
+
+		WRITE_ONCE(pn->state, vcpu_halted);
+		if (!lp) { /* ONCE */
+			lp = pv_hash(lock, pn);
+			/*
+			 * lp must be set before setting _Q_SLOW_VAL
+			 *
+			 * [S] lp = lock                [RmW] l = l->locked = 0
+			 *     MB                             MB
+			 * [S] l->locked = _Q_SLOW_VAL  [L]   lp
+			 *
+			 * Matches the cmpxchg() in __pv_queued_spin_unlock().
+			 */
+			if (!cmpxchg(&l->locked, _Q_LOCKED_VAL, _Q_SLOW_VAL)) {
+				/*
+				 * The lock is free and _Q_SLOW_VAL has never
+				 * been set. Therefore we need to unhash before
+				 * getting the lock.
+				 */
+				WRITE_ONCE(*lp, NULL);
+				return;
+			}
+		}
+		pv_wait(&l->locked, _Q_SLOW_VAL);
+
+		/*
+		 * The unlocker should have freed the lock before kicking the
+		 * CPU. So if the lock is still not free, it is a spurious
+		 * wakeup and so the vCPU should wait again after spinning for
+		 * a while.
+		 */
+	}
+
+	/*
+	 * Lock is unlocked now; the caller will acquire it without waiting.
+	 * As with pv_wait_node() we rely on the caller to do a load-acquire
+	 * for us.
+	 */
+}
+
+/*
+ * PV version of the unlock function to be used in stead of
+ * queued_spin_unlock().
+ */
+__visible void __pv_queued_spin_unlock(struct qspinlock *lock)
+{
+	struct __qspinlock *l = (void *)lock;
+	struct pv_node *node;
+
+	/*
+	 * We must not unlock if SLOW, because in that case we must first
+	 * unhash. Otherwise it would be possible to have multiple @lock
+	 * entries, which would be BAD.
+	 */
+	if (likely(cmpxchg(&l->locked, _Q_LOCKED_VAL, 0) == _Q_LOCKED_VAL))
+		return;
+
+	/*
+	 * Since the above failed to release, this must be the SLOW path.
+	 * Therefore start by looking up the blocked node and unhashing it.
+	 */
+	node = pv_unhash(lock);
+
+	/*
+	 * Now that we have a reference to the (likely) blocked pv_node,
+	 * release the lock.
+	 */
+	smp_store_release(&l->locked, 0);
+
+	/*
+	 * At this point the memory pointed at by lock can be freed/reused,
+	 * however we can still use the pv_node to kick the CPU.
+	 */
+	if (READ_ONCE(node->state) == vcpu_halted)
+		pv_kick(node->cpu);
+}
+/*
+ * Include the architecture specific callee-save thunk of the
+ * __pv_queued_spin_unlock(). This thunk is put together with
+ * __pv_queued_spin_unlock() near the top of the file to make sure
+ * that the callee-save thunk and the real unlock function are close
+ * to each other sharing consecutive instruction cachelines.
+ */
+#include <asm/qspinlock_paravirt.h>
+
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index b73279367087..30ec5b46cd8c 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -70,10 +70,10 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
 }
 
 /*
- * We can speed up the acquire/release, if the architecture
- * supports cmpxchg and if there's no debugging state to be set up
+ * We can speed up the acquire/release, if there's no debugging state to be
+ * set up.
  */
-#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES)
+#ifndef CONFIG_DEBUG_RT_MUTEXES
 # define rt_mutex_cmpxchg(l,c,n)	(cmpxchg(&l->owner, c, n) == c)
 static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
 {
@@ -265,15 +265,17 @@ struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
 }
 
 /*
- * Called by sched_setscheduler() to check whether the priority change
- * is overruled by a possible priority boosting.
+ * Called by sched_setscheduler() to get the priority which will be
+ * effective after the change.
  */
-int rt_mutex_check_prio(struct task_struct *task, int newprio)
+int rt_mutex_get_effective_prio(struct task_struct *task, int newprio)
 {
 	if (!task_has_pi_waiters(task))
-		return 0;
+		return newprio;
 
-	return task_top_pi_waiter(task)->task->prio <= newprio;
+	if (task_top_pi_waiter(task)->task->prio <= newprio)
+		return task_top_pi_waiter(task)->task->prio;
+	return newprio;
 }
 
 /*
@@ -1441,10 +1443,17 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
  *
  * @lock:	the rt_mutex to be locked
  *
+ * This function can only be called in thread context. It's safe to
+ * call it from atomic regions, but not from hard interrupt or soft
+ * interrupt context.
+ *
  * Returns 1 on success and 0 on contention
  */
 int __sched rt_mutex_trylock(struct rt_mutex *lock)
 {
+	if (WARN_ON(in_irq() || in_nmi() || in_serving_softirq()))
+		return 0;
+
 	return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_trylock);
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 3417d0172a5d..0f189714e457 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -409,11 +409,24 @@ done:
 	return taken;
 }
 
+/*
+ * Return true if the rwsem has active spinner
+ */
+static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
+{
+	return osq_is_locked(&sem->osq);
+}
+
 #else
 static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 {
 	return false;
 }
+
+static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
+{
+	return false;
+}
 #endif
 
 /*
@@ -496,7 +509,38 @@ struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
 {
 	unsigned long flags;
 
+	/*
+	 * If a spinner is present, it is not necessary to do the wakeup.
+	 * Try to do wakeup only if the trylock succeeds to minimize
+	 * spinlock contention which may introduce too much delay in the
+	 * unlock operation.
+	 *
+	 *    spinning writer		up_write/up_read caller
+	 *    ---------------		-----------------------
+	 * [S]   osq_unlock()		[L]   osq
+	 *	 MB			      RMB
+	 * [RmW] rwsem_try_write_lock() [RmW] spin_trylock(wait_lock)
+	 *
+	 * Here, it is important to make sure that there won't be a missed
+	 * wakeup while the rwsem is free and the only spinning writer goes
+	 * to sleep without taking the rwsem. Even when the spinning writer
+	 * is just going to break out of the waiting loop, it will still do
+	 * a trylock in rwsem_down_write_failed() before sleeping. IOW, if
+	 * rwsem_has_spinner() is true, it will guarantee at least one
+	 * trylock attempt on the rwsem later on.
+	 */
+	if (rwsem_has_spinner(sem)) {
+		/*
+		 * The smp_rmb() here is to make sure that the spinner
+		 * state is consulted before reading the wait_lock.
+		 */
+		smp_rmb();
+		if (!raw_spin_trylock_irqsave(&sem->wait_lock, flags))
+			return sem;
+		goto locked;
+	}
 	raw_spin_lock_irqsave(&sem->wait_lock, flags);
+locked:
 
 	/* do nothing if list empty */
 	if (!list_empty(&sem->wait_list))
diff --git a/kernel/module.c b/kernel/module.c
index 42a1d2afb217..cfc9e843a924 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3370,6 +3370,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	module_bug_cleanup(mod);
 	mutex_unlock(&module_mutex);
 
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_GOING, mod);
+
 	/* we can't deallocate the module until we clear memory protection */
 	unset_module_init_ro_nx(mod);
 	unset_module_core_ro_nx(mod);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 233165da782f..8cf7304b2867 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -162,11 +162,14 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
 static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;
 module_param(kthread_prio, int, 0644);
 
-/* Delay in jiffies for grace-period initialization delays. */
-static int gp_init_delay = IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT)
-				? CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY
-				: 0;
+/* Delay in jiffies for grace-period initialization delays, debug only. */
+#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT
+static int gp_init_delay = CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY;
 module_param(gp_init_delay, int, 0644);
+#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+static const int gp_init_delay;
+#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+#define PER_RCU_NODE_PERIOD 10	/* Number of grace periods between delays. */
 
 /*
  * Track the rcutorture test sequence number and the update version
@@ -1843,9 +1846,8 @@ static int rcu_gp_init(struct rcu_state *rsp)
 		raw_spin_unlock_irq(&rnp->lock);
 		cond_resched_rcu_qs();
 		ACCESS_ONCE(rsp->gp_activity) = jiffies;
-		if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT) &&
-		    gp_init_delay > 0 &&
-		    !(rsp->gpnum % (rcu_num_nodes * 10)))
+		if (gp_init_delay > 0 &&
+		    !(rsp->gpnum % (rcu_num_nodes * PER_RCU_NODE_PERIOD)))
 			schedule_timeout_uninterruptible(gp_init_delay);
 	}
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fe22f7510bce..123673291ffb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3300,15 +3300,18 @@ static void __setscheduler_params(struct task_struct *p,
 
 /* Actually do priority change: must hold pi & rq lock. */
 static void __setscheduler(struct rq *rq, struct task_struct *p,
-			   const struct sched_attr *attr)
+			   const struct sched_attr *attr, bool keep_boost)
 {
 	__setscheduler_params(p, attr);
 
 	/*
-	 * If we get here, there was no pi waiters boosting the
-	 * task. It is safe to use the normal prio.
+	 * Keep a potential priority boosting if called from
+	 * sched_setscheduler().
 	 */
-	p->prio = normal_prio(p);
+	if (keep_boost)
+		p->prio = rt_mutex_get_effective_prio(p, normal_prio(p));
+	else
+		p->prio = normal_prio(p);
 
 	if (dl_prio(p->prio))
 		p->sched_class = &dl_sched_class;
@@ -3408,7 +3411,7 @@ static int __sched_setscheduler(struct task_struct *p,
 	int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
 		      MAX_RT_PRIO - 1 - attr->sched_priority;
 	int retval, oldprio, oldpolicy = -1, queued, running;
-	int policy = attr->sched_policy;
+	int new_effective_prio, policy = attr->sched_policy;
 	unsigned long flags;
 	const struct sched_class *prev_class;
 	struct rq *rq;
@@ -3590,15 +3593,14 @@ change:
 	oldprio = p->prio;
 
 	/*
-	 * Special case for priority boosted tasks.
-	 *
-	 * If the new priority is lower or equal (user space view)
-	 * than the current (boosted) priority, we just store the new
+	 * Take priority boosted tasks into account. If the new
+	 * effective priority is unchanged, we just store the new
 	 * normal parameters and do not touch the scheduler class and
 	 * the runqueue. This will be done when the task deboost
 	 * itself.
 	 */
-	if (rt_mutex_check_prio(p, newprio)) {
+	new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
+	if (new_effective_prio == oldprio) {
 		__setscheduler_params(p, attr);
 		task_rq_unlock(rq, p, &flags);
 		return 0;
@@ -3612,7 +3614,7 @@ change:
 		put_prev_task(rq, p);
 
 	prev_class = p->sched_class;
-	__setscheduler(rq, p, attr);
+	__setscheduler(rq, p, attr, true);
 
 	if (running)
 		p->sched_class->set_curr_task(rq);
@@ -4387,10 +4389,7 @@ long __sched io_schedule_timeout(long timeout)
 	long ret;
 
 	current->in_iowait = 1;
-	if (old_iowait)
-		blk_schedule_flush_plug(current);
-	else
-		blk_flush_plug(current);
+	blk_schedule_flush_plug(current);
 
 	delayacct_blkio_start();
 	rq = raw_rq();
@@ -6997,27 +6996,23 @@ static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
 	unsigned long flags;
 	long cpu = (long)hcpu;
 	struct dl_bw *dl_b;
+	bool overflow;
+	int cpus;
 
-	switch (action & ~CPU_TASKS_FROZEN) {
+	switch (action) {
 	case CPU_DOWN_PREPARE:
-		/* explicitly allow suspend */
-		if (!(action & CPU_TASKS_FROZEN)) {
-			bool overflow;
-			int cpus;
-
-			rcu_read_lock_sched();
-			dl_b = dl_bw_of(cpu);
+		rcu_read_lock_sched();
+		dl_b = dl_bw_of(cpu);
 
-			raw_spin_lock_irqsave(&dl_b->lock, flags);
-			cpus = dl_bw_cpus(cpu);
-			overflow = __dl_overflow(dl_b, cpus, 0, 0);
-			raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+		raw_spin_lock_irqsave(&dl_b->lock, flags);
+		cpus = dl_bw_cpus(cpu);
+		overflow = __dl_overflow(dl_b, cpus, 0, 0);
+		raw_spin_unlock_irqrestore(&dl_b->lock, flags);
 
-			rcu_read_unlock_sched();
+		rcu_read_unlock_sched();
 
-			if (overflow)
-				return notifier_from_errno(-EBUSY);
-		}
+		if (overflow)
+			return notifier_from_errno(-EBUSY);
 		cpuset_update_active_cpus(false);
 		break;
 	case CPU_DOWN_PREPARE_FROZEN:
@@ -7346,7 +7341,7 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
 	queued = task_on_rq_queued(p);
 	if (queued)
 		dequeue_task(rq, p, 0);
-	__setscheduler(rq, p, &attr);
+	__setscheduler(rq, p, &attr, false);
 	if (queued) {
 		enqueue_task(rq, p, 0);
 		resched_curr(rq);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 852143a79f36..9bc82329eaad 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -341,7 +341,7 @@ long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
 	 * condition being true _OR_ WQ_FLAG_WOKEN such that we will not miss
 	 * an event.
 	 */
-	set_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
+	smp_store_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
 
 	return timeout;
 }
@@ -354,7 +354,7 @@ int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
 	 * doesn't imply write barrier and the users expects write
 	 * barrier semantics on wakeup functions.  The following
 	 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
-	 * and is paired with set_mb() in wait_woken().
+	 * and is paired with smp_store_mb() in wait_woken().
 	 */
 	smp_wmb(); /* C */
 	wait->flags |= WQ_FLAG_WOKEN;
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 11dc22a6983b..637a09461c1d 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -117,11 +117,7 @@ static int __clockevents_set_state(struct clock_event_device *dev,
 	/* Transition with new state-specific callbacks */
 	switch (state) {
 	case CLOCK_EVT_STATE_DETACHED:
-		/*
-		 * This is an internal state, which is guaranteed to go from
-		 * SHUTDOWN to DETACHED. No driver interaction required.
-		 */
-		return 0;
+		/* The clockevent device is getting replaced. Shut it down. */
 
 	case CLOCK_EVT_STATE_SHUTDOWN:
 		return dev->set_state_shutdown(dev);
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 76d4bd962b19..93ef7190bdea 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -266,21 +266,23 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 /*
  * Divide a ktime value by a nanosecond value
  */
-u64 __ktime_divns(const ktime_t kt, s64 div)
+s64 __ktime_divns(const ktime_t kt, s64 div)
 {
-	u64 dclc;
 	int sft = 0;
+	s64 dclc;
+	u64 tmp;
 
 	dclc = ktime_to_ns(kt);
+	tmp = dclc < 0 ? -dclc : dclc;
+
 	/* Make sure the divisor is less than 2^32: */
 	while (div >> 32) {
 		sft++;
 		div >>= 1;
 	}
-	dclc >>= sft;
-	do_div(dclc, (unsigned long) div);
-
-	return dclc;
+	tmp >>= sft;
+	do_div(tmp, (unsigned long) div);
+	return dclc < 0 ? -tmp : tmp;
 }
 EXPORT_SYMBOL_GPL(__ktime_divns);
 #endif /* BITS_PER_LONG >= 64 */
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 692bf7184c8c..25a086bcb700 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -178,12 +178,13 @@ ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 EXPORT_SYMBOL(ftrace_print_hex_seq);
 
 const char *
-ftrace_print_array_seq(struct trace_seq *p, const void *buf, int buf_len,
+ftrace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 		       size_t el_size)
 {
 	const char *ret = trace_seq_buffer_ptr(p);
 	const char *prefix = "";
 	void *ptr = (void *)buf;
+	size_t buf_len = count * el_size;
 
 	trace_seq_putc(p, '{');
 
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 2316f50b07a4..581a68a04c64 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -41,6 +41,8 @@
 #define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
 #define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
 
+static DEFINE_MUTEX(watchdog_proc_mutex);
+
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
 #else
@@ -608,26 +610,36 @@ void watchdog_nmi_enable_all(void)
 {
 	int cpu;
 
-	if (!watchdog_user_enabled)
-		return;
+	mutex_lock(&watchdog_proc_mutex);
+
+	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+		goto unlock;
 
 	get_online_cpus();
 	for_each_online_cpu(cpu)
 		watchdog_nmi_enable(cpu);
 	put_online_cpus();
+
+unlock:
+	mutex_unlock(&watchdog_proc_mutex);
 }
 
 void watchdog_nmi_disable_all(void)
 {
 	int cpu;
 
+	mutex_lock(&watchdog_proc_mutex);
+
 	if (!watchdog_running)
-		return;
+		goto unlock;
 
 	get_online_cpus();
 	for_each_online_cpu(cpu)
 		watchdog_nmi_disable(cpu);
 	put_online_cpus();
+
+unlock:
+	mutex_unlock(&watchdog_proc_mutex);
 }
 #else
 static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
@@ -744,8 +756,6 @@ static int proc_watchdog_update(void)
 
 }
 
-static DEFINE_MUTEX(watchdog_proc_mutex);
-
 /*
  * common function for watchdog, nmi_watchdog and soft_watchdog parameter
  *