Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "This is much bigger than typical fixes, but Peter found a category of
  races that spurred more fixes and more debugging enhancements.  Work
  started before the merge window, but got finished only now.

  Aside of that this contains the usual small fixes to perf and tools.
  Nothing particular exciting"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  perf: Remove/simplify lockdep annotation
  perf: Synchronously clean up child events
  perf: Untangle 'owner' confusion
  perf: Add flags argument to perf_remove_from_context()
  perf: Clean up sync_child_event()
  perf: Robustify event->owner usage and SMP ordering
  perf: Fix STATE_EXIT usage
  perf: Update locking order
  perf: Remove __free_event()
  perf/bpf: Convert perf_event_array to use struct file
  perf: Fix NULL deref
  perf/x86: De-obfuscate code
  perf/x86: Fix uninitialized value usage
  perf: Fix race in perf_event_exit_task_context()
  perf: Fix orphan hole
  perf stat: Do not clean event's private stats
  perf hists: Fix HISTC_MEM_DCACHELINE width setting
  perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
  perf tests: Remove wrong semicolon in while loop in CQM test
  perf: Synchronously free aux pages in case of allocation failure
  ...

19 files changed, 746 insertions, 667 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index a667078a5180..fed2ab1f1065 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1960,7 +1960,8 @@ intel_bts_constraints(struct perf_event *event)
 
 static int intel_alt_er(int idx, u64 config)
 {
-	int alt_idx;
+	int alt_idx = idx;
+
 	if (!(x86_pmu.flags & PMU_FL_HAS_RSP_1))
 		return idx;
 
@@ -2897,14 +2898,12 @@ static void intel_pmu_cpu_starting(int cpu)
 		return;
 
 	if (!(x86_pmu.flags & PMU_FL_NO_HT_SHARING)) {
-		void **onln = &cpuc->kfree_on_online[X86_PERF_KFREE_SHARED];
-
 		for_each_cpu(i, topology_sibling_cpumask(cpu)) {
 			struct intel_shared_regs *pc;
 
 			pc = per_cpu(cpu_hw_events, i).shared_regs;
 			if (pc && pc->core_id == core_id) {
-				*onln = cpuc->shared_regs;
+				cpuc->kfree_on_online[0] = cpuc->shared_regs;
 				cpuc->shared_regs = pc;
 				break;
 			}
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index f97f8075bf04..3bf41d413775 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -995,6 +995,9 @@ static int __init uncore_pci_init(void)
 	case 87: /* Knights Landing */
 		ret = knl_uncore_pci_init();
 		break;
+	case 94: /* SkyLake */
+		ret = skl_uncore_pci_init();
+		break;
 	default:
 		return 0;
 	}
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.h b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
index 07aa2d6bd710..a7086b862156 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.h
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
@@ -336,6 +336,7 @@ int snb_uncore_pci_init(void);
 int ivb_uncore_pci_init(void);
 int hsw_uncore_pci_init(void);
 int bdw_uncore_pci_init(void);
+int skl_uncore_pci_init(void);
 void snb_uncore_cpu_init(void);
 void nhm_uncore_cpu_init(void);
 int snb_pci2phy_map_init(int devid);
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c b/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c
index 0b934820fafd..2bd030ddd0db 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c
@@ -8,6 +8,7 @@
 #define PCI_DEVICE_ID_INTEL_HSW_IMC	0x0c00
 #define PCI_DEVICE_ID_INTEL_HSW_U_IMC	0x0a04
 #define PCI_DEVICE_ID_INTEL_BDW_IMC	0x1604
+#define PCI_DEVICE_ID_INTEL_SKL_IMC	0x191f
 
 /* SNB event control */
 #define SNB_UNC_CTL_EV_SEL_MASK			0x000000ff
@@ -524,6 +525,14 @@ static const struct pci_device_id bdw_uncore_pci_ids[] = {
 	{ /* end: all zeroes */ },
 };
 
+static const struct pci_device_id skl_uncore_pci_ids[] = {
+	{ /* IMC */
+		PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SKL_IMC),
+		.driver_data = UNCORE_PCI_DEV_DATA(SNB_PCI_UNCORE_IMC, 0),
+	},
+	{ /* end: all zeroes */ },
+};
+
 static struct pci_driver snb_uncore_pci_driver = {
 	.name		= "snb_uncore",
 	.id_table	= snb_uncore_pci_ids,
@@ -544,6 +553,11 @@ static struct pci_driver bdw_uncore_pci_driver = {
 	.id_table	= bdw_uncore_pci_ids,
 };
 
+static struct pci_driver skl_uncore_pci_driver = {
+	.name		= "skl_uncore",
+	.id_table	= skl_uncore_pci_ids,
+};
+
 struct imc_uncore_pci_dev {
 	__u32 pci_id;
 	struct pci_driver *driver;
@@ -558,6 +572,7 @@ static const struct imc_uncore_pci_dev desktop_imc_pci_ids[] = {
 	IMC_DEV(HSW_IMC, &hsw_uncore_pci_driver),    /* 4th Gen Core Processor */
 	IMC_DEV(HSW_U_IMC, &hsw_uncore_pci_driver),  /* 4th Gen Core ULT Mobile Processor */
 	IMC_DEV(BDW_IMC, &bdw_uncore_pci_driver),    /* 5th Gen Core U */
+	IMC_DEV(SKL_IMC, &skl_uncore_pci_driver),    /* 6th Gen Core */
 	{  /* end marker */ }
 };
 
@@ -610,6 +625,11 @@ int bdw_uncore_pci_init(void)
 	return imc_uncore_pci_init();
 }
 
+int skl_uncore_pci_init(void)
+{
+	return imc_uncore_pci_init();
+}
+
 /* end of Sandy Bridge uncore support */
 
 /* Nehalem uncore support */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f9828a48f16a..b35a61a481fa 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -634,9 +634,6 @@ struct perf_event_context {
 	int				nr_cgroups;	 /* cgroup evts */
 	void				*task_ctx_data; /* pmu specific data */
 	struct rcu_head			rcu_head;
-
-	struct delayed_work		orphans_remove;
-	bool				orphans_remove_sched;
 };
 
 /*
@@ -729,7 +726,7 @@ extern int perf_event_init_task(struct task_struct *child);
 extern void perf_event_exit_task(struct task_struct *child);
 extern void perf_event_free_task(struct task_struct *task);
 extern void perf_event_delayed_put(struct task_struct *task);
-extern struct perf_event *perf_event_get(unsigned int fd);
+extern struct file *perf_event_get(unsigned int fd);
 extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
 extern void perf_event_print_debug(void);
 extern void perf_pmu_disable(struct pmu *pmu);
@@ -1044,7 +1041,7 @@ extern void perf_swevent_put_recursion_context(int rctx);
 extern u64 perf_swevent_set_period(struct perf_event *event);
 extern void perf_event_enable(struct perf_event *event);
 extern void perf_event_disable(struct perf_event *event);
-extern int __perf_event_disable(void *info);
+extern void perf_event_disable_local(struct perf_event *event);
 extern void perf_event_task_tick(void);
 #else /* !CONFIG_PERF_EVENTS: */
 static inline void *
@@ -1070,7 +1067,7 @@ static inline int perf_event_init_task(struct task_struct *child)	{ return 0; }
 static inline void perf_event_exit_task(struct task_struct *child)	{ }
 static inline void perf_event_free_task(struct task_struct *task)	{ }
 static inline void perf_event_delayed_put(struct task_struct *task)	{ }
-static inline struct perf_event *perf_event_get(unsigned int fd)	{ return ERR_PTR(-EINVAL); }
+static inline struct file *perf_event_get(unsigned int fd)	{ return ERR_PTR(-EINVAL); }
 static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
 {
 	return ERR_PTR(-EINVAL);
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index b0799bced518..89ebbc4d1164 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -291,10 +291,13 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
 {
 	struct perf_event *event;
 	const struct perf_event_attr *attr;
+	struct file *file;
 
-	event = perf_event_get(fd);
-	if (IS_ERR(event))
-		return event;
+	file = perf_event_get(fd);
+	if (IS_ERR(file))
+		return file;
+
+	event = file->private_data;
 
 	attr = perf_event_attrs(event);
 	if (IS_ERR(attr))
@@ -304,24 +307,22 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
 		goto err;
 
 	if (attr->type == PERF_TYPE_RAW)
-		return event;
+		return file;
 
 	if (attr->type == PERF_TYPE_HARDWARE)
-		return event;
+		return file;
 
 	if (attr->type == PERF_TYPE_SOFTWARE &&
 	    attr->config == PERF_COUNT_SW_BPF_OUTPUT)
-		return event;
+		return file;
 err:
-	perf_event_release_kernel(event);
+	fput(file);
 	return ERR_PTR(-EINVAL);
 }
 
 static void perf_event_fd_array_put_ptr(void *ptr)
 {
-	struct perf_event *event = ptr;
-
-	perf_event_release_kernel(event);
+	fput((struct file *)ptr);
 }
 
 static const struct bpf_map_ops perf_event_array_ops = {
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 06ae52e99ac2..5946460b2425 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -49,8 +49,6 @@
 
 #include <asm/irq_regs.h>
 
-static struct workqueue_struct *perf_wq;
-
 typedef int (*remote_function_f)(void *);
 
 struct remote_function_call {
@@ -126,44 +124,181 @@ static int cpu_function_call(int cpu, remote_function_f func, void *info)
 	return data.ret;
 }
 
-static void event_function_call(struct perf_event *event,
-				int (*active)(void *),
-				void (*inactive)(void *),
-				void *data)
+static inline struct perf_cpu_context *
+__get_cpu_context(struct perf_event_context *ctx)
+{
+	return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
+}
+
+static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
+			  struct perf_event_context *ctx)
+{
+	raw_spin_lock(&cpuctx->ctx.lock);
+	if (ctx)
+		raw_spin_lock(&ctx->lock);
+}
+
+static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
+			    struct perf_event_context *ctx)
+{
+	if (ctx)
+		raw_spin_unlock(&ctx->lock);
+	raw_spin_unlock(&cpuctx->ctx.lock);
+}
+
+#define TASK_TOMBSTONE ((void *)-1L)
+
+static bool is_kernel_event(struct perf_event *event)
+{
+	return READ_ONCE(event->owner) == TASK_TOMBSTONE;
+}
+
+/*
+ * On task ctx scheduling...
+ *
+ * When !ctx->nr_events a task context will not be scheduled. This means
+ * we can disable the scheduler hooks (for performance) without leaving
+ * pending task ctx state.
+ *
+ * This however results in two special cases:
+ *
+ *  - removing the last event from a task ctx; this is relatively straight
+ *    forward and is done in __perf_remove_from_context.
+ *
+ *  - adding the first event to a task ctx; this is tricky because we cannot
+ *    rely on ctx->is_active and therefore cannot use event_function_call().
+ *    See perf_install_in_context().
+ *
+ * This is because we need a ctx->lock serialized variable (ctx->is_active)
+ * to reliably determine if a particular task/context is scheduled in. The
+ * task_curr() use in task_function_call() is racy in that a remote context
+ * switch is not a single atomic operation.
+ *
+ * As is, the situation is 'safe' because we set rq->curr before we do the
+ * actual context switch. This means that task_curr() will fail early, but
+ * we'll continue spinning on ctx->is_active until we've passed
+ * perf_event_task_sched_out().
+ *
+ * Without this ctx->lock serialized variable we could have race where we find
+ * the task (and hence the context) would not be active while in fact they are.
+ *
+ * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
+ */
+
+typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
+			struct perf_event_context *, void *);
+
+struct event_function_struct {
+	struct perf_event *event;
+	event_f func;
+	void *data;
+};
+
+static int event_function(void *info)
+{
+	struct event_function_struct *efs = info;
+	struct perf_event *event = efs->event;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+	struct perf_event_context *task_ctx = cpuctx->task_ctx;
+	int ret = 0;
+
+	WARN_ON_ONCE(!irqs_disabled());
+
+	perf_ctx_lock(cpuctx, task_ctx);
+	/*
+	 * Since we do the IPI call without holding ctx->lock things can have
+	 * changed, double check we hit the task we set out to hit.
+	 */
+	if (ctx->task) {
+		if (ctx->task != current) {
+			ret = -EAGAIN;
+			goto unlock;
+		}
+
+		/*
+		 * We only use event_function_call() on established contexts,
+		 * and event_function() is only ever called when active (or
+		 * rather, we'll have bailed in task_function_call() or the
+		 * above ctx->task != current test), therefore we must have
+		 * ctx->is_active here.
+		 */
+		WARN_ON_ONCE(!ctx->is_active);
+		/*
+		 * And since we have ctx->is_active, cpuctx->task_ctx must
+		 * match.
+		 */
+		WARN_ON_ONCE(task_ctx != ctx);
+	} else {
+		WARN_ON_ONCE(&cpuctx->ctx != ctx);
+	}
+
+	efs->func(event, cpuctx, ctx, efs->data);
+unlock:
+	perf_ctx_unlock(cpuctx, task_ctx);
+
+	return ret;
+}
+
+static void event_function_local(struct perf_event *event, event_f func, void *data)
+{
+	struct event_function_struct efs = {
+		.event = event,
+		.func = func,
+		.data = data,
+	};
+
+	int ret = event_function(&efs);
+	WARN_ON_ONCE(ret);
+}
+
+static void event_function_call(struct perf_event *event, event_f func, void *data)
 {
 	struct perf_event_context *ctx = event->ctx;
-	struct task_struct *task = ctx->task;
+	struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
+	struct event_function_struct efs = {
+		.event = event,
+		.func = func,
+		.data = data,
+	};
+
+	if (!event->parent) {
+		/*
+		 * If this is a !child event, we must hold ctx::mutex to
+		 * stabilize the the event->ctx relation. See
+		 * perf_event_ctx_lock().
+		 */
+		lockdep_assert_held(&ctx->mutex);
+	}
 
 	if (!task) {
-		cpu_function_call(event->cpu, active, data);
+		cpu_function_call(event->cpu, event_function, &efs);
 		return;
 	}
 
 again:
-	if (!task_function_call(task, active, data))
+	if (task == TASK_TOMBSTONE)
+		return;
+
+	if (!task_function_call(task, event_function, &efs))
 		return;
 
 	raw_spin_lock_irq(&ctx->lock);
-	if (ctx->is_active) {
-		/*
-		 * Reload the task pointer, it might have been changed by
-		 * a concurrent perf_event_context_sched_out().
-		 */
-		task = ctx->task;
-		raw_spin_unlock_irq(&ctx->lock);
-		goto again;
+	/*
+	 * Reload the task pointer, it might have been changed by
+	 * a concurrent perf_event_context_sched_out().
+	 */
+	task = ctx->task;
+	if (task != TASK_TOMBSTONE) {
+		if (ctx->is_active) {
+			raw_spin_unlock_irq(&ctx->lock);
+			goto again;
+		}
+		func(event, NULL, ctx, data);
 	}
-	inactive(data);
 	raw_spin_unlock_irq(&ctx->lock);
 }
 
-#define EVENT_OWNER_KERNEL ((void *) -1)
-
-static bool is_kernel_event(struct perf_event *event)
-{
-	return event->owner == EVENT_OWNER_KERNEL;
-}
-
 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
 		       PERF_FLAG_FD_OUTPUT  |\
 		       PERF_FLAG_PID_CGROUP |\
@@ -368,28 +503,6 @@ static inline u64 perf_event_clock(struct perf_event *event)
 	return event->clock();
 }
 
-static inline struct perf_cpu_context *
-__get_cpu_context(struct perf_event_context *ctx)
-{
-	return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
-}
-
-static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
-			  struct perf_event_context *ctx)
-{
-	raw_spin_lock(&cpuctx->ctx.lock);
-	if (ctx)
-		raw_spin_lock(&ctx->lock);
-}
-
-static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
-			    struct perf_event_context *ctx)
-{
-	if (ctx)
-		raw_spin_unlock(&ctx->lock);
-	raw_spin_unlock(&cpuctx->ctx.lock);
-}
-
 #ifdef CONFIG_CGROUP_PERF
 
 static inline bool
@@ -579,13 +692,7 @@ static inline void perf_cgroup_sched_out(struct task_struct *task,
 	 * we are holding the rcu lock
 	 */
 	cgrp1 = perf_cgroup_from_task(task, NULL);
-
-	/*
-	 * next is NULL when called from perf_event_enable_on_exec()
-	 * that will systematically cause a cgroup_switch()
-	 */
-	if (next)
-		cgrp2 = perf_cgroup_from_task(next, NULL);
+	cgrp2 = perf_cgroup_from_task(next, NULL);
 
 	/*
 	 * only schedule out current cgroup events if we know
@@ -611,8 +718,6 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
 	 * we are holding the rcu lock
 	 */
 	cgrp1 = perf_cgroup_from_task(task, NULL);
-
-	/* prev can never be NULL */
 	cgrp2 = perf_cgroup_from_task(prev, NULL);
 
 	/*
@@ -917,7 +1022,7 @@ static void put_ctx(struct perf_event_context *ctx)
 	if (atomic_dec_and_test(&ctx->refcount)) {
 		if (ctx->parent_ctx)
 			put_ctx(ctx->parent_ctx);
-		if (ctx->task)
+		if (ctx->task && ctx->task != TASK_TOMBSTONE)
 			put_task_struct(ctx->task);
 		call_rcu(&ctx->rcu_head, free_ctx);
 	}
@@ -934,9 +1039,8 @@ static void put_ctx(struct perf_event_context *ctx)
  * 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_exit_event()
+ *        put_event()			[ parent, 1 ]
  *
  *  - perf_event_init_context()		[ parent, 0 ]
  *      inherit_task_group()
@@ -979,8 +1083,8 @@ static void put_ctx(struct perf_event_context *ctx)
  * Lock order:
  *	task_struct::perf_event_mutex
  *	  perf_event_context::mutex
- *	    perf_event_context::lock
  *	    perf_event::child_mutex;
+ *	      perf_event_context::lock
  *	    perf_event::mmap_mutex
  *	    mmap_sem
  */
@@ -1078,6 +1182,7 @@ static u64 primary_event_id(struct perf_event *event)
 
 /*
  * Get the perf_event_context for a task and lock it.
+ *
  * This has to cope with with the fact that until it is locked,
  * the context could get moved to another task.
  */
@@ -1118,9 +1223,12 @@ retry:
 			goto retry;
 		}
 
-		if (!atomic_inc_not_zero(&ctx->refcount)) {
+		if (ctx->task == TASK_TOMBSTONE ||
+		    !atomic_inc_not_zero(&ctx->refcount)) {
 			raw_spin_unlock(&ctx->lock);
 			ctx = NULL;
+		} else {
+			WARN_ON_ONCE(ctx->task != task);
 		}
 	}
 	rcu_read_unlock();
@@ -1246,6 +1354,8 @@ ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
 static void
 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
 {
+	lockdep_assert_held(&ctx->lock);
+
 	WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
 	event->attach_state |= PERF_ATTACH_CONTEXT;
 
@@ -1448,11 +1558,14 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
 
 	if (is_cgroup_event(event)) {
 		ctx->nr_cgroups--;
+		/*
+		 * Because cgroup events are always per-cpu events, this will
+		 * always be called from the right CPU.
+		 */
 		cpuctx = __get_cpu_context(ctx);
 		/*
-		 * if there are no more cgroup events
-		 * then cler cgrp to avoid stale pointer
-		 * in update_cgrp_time_from_cpuctx()
+		 * If there are no more cgroup events then clear cgrp to avoid
+		 * stale pointer in update_cgrp_time_from_cpuctx().
 		 */
 		if (!ctx->nr_cgroups)
 			cpuctx->cgrp = NULL;
@@ -1530,45 +1643,11 @@ out:
 		perf_event__header_size(tmp);
 }
 
-/*
- * User event without the task.
- */
 static bool is_orphaned_event(struct perf_event *event)
 {
-	return event && !is_kernel_event(event) && !event->owner;
+	return event->state == PERF_EVENT_STATE_EXIT;
 }
 
-/*
- * Event has a parent but parent's task finished and it's
- * alive only because of children holding refference.
- */
-static bool is_orphaned_child(struct perf_event *event)
-{
-	return is_orphaned_event(event->parent);
-}
-
-static void orphans_remove_work(struct work_struct *work);
-
-static void schedule_orphans_remove(struct perf_event_context *ctx)
-{
-	if (!ctx->task || ctx->orphans_remove_sched || !perf_wq)
-		return;
-
-	if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) {
-		get_ctx(ctx);
-		ctx->orphans_remove_sched = true;
-	}
-}
-
-static int __init perf_workqueue_init(void)
-{
-	perf_wq = create_singlethread_workqueue("perf");
-	WARN(!perf_wq, "failed to create perf workqueue\n");
-	return perf_wq ? 0 : -1;
-}
-
-core_initcall(perf_workqueue_init);
-
 static inline int pmu_filter_match(struct perf_event *event)
 {
 	struct pmu *pmu = event->pmu;
@@ -1629,9 +1708,6 @@ event_sched_out(struct perf_event *event,
 	if (event->attr.exclusive || !cpuctx->active_oncpu)
 		cpuctx->exclusive = 0;
 
-	if (is_orphaned_child(event))
-		schedule_orphans_remove(ctx);
-
 	perf_pmu_enable(event->pmu);
 }
 
@@ -1655,21 +1731,8 @@ group_sched_out(struct perf_event *group_event,
 		cpuctx->exclusive = 0;
 }
 
-struct remove_event {
-	struct perf_event *event;
-	bool detach_group;
-};
-
-static void ___perf_remove_from_context(void *info)
-{
-	struct remove_event *re = info;
-	struct perf_event *event = re->event;
-	struct perf_event_context *ctx = event->ctx;
-
-	if (re->detach_group)
-		perf_group_detach(event);
-	list_del_event(event, ctx);
-}
+#define DETACH_GROUP	0x01UL
+#define DETACH_STATE	0x02UL
 
 /*
  * Cross CPU call to remove a performance event
@@ -1677,33 +1740,33 @@ static void ___perf_remove_from_context(void *info)
  * We disable the event on the hardware level first. After that we
  * remove it from the context list.
  */
-static int __perf_remove_from_context(void *info)
+static void
+__perf_remove_from_context(struct perf_event *event,
+			   struct perf_cpu_context *cpuctx,
+			   struct perf_event_context *ctx,
+			   void *info)
 {
-	struct remove_event *re = info;
-	struct perf_event *event = re->event;
-	struct perf_event_context *ctx = event->ctx;
-	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+	unsigned long flags = (unsigned long)info;
 
-	raw_spin_lock(&ctx->lock);
 	event_sched_out(event, cpuctx, ctx);
-	if (re->detach_group)
+	if (flags & DETACH_GROUP)
 		perf_group_detach(event);
 	list_del_event(event, ctx);
-	if (!ctx->nr_events && cpuctx->task_ctx == ctx) {
+	if (flags & DETACH_STATE)
+		event->state = PERF_EVENT_STATE_EXIT;
+
+	if (!ctx->nr_events && ctx->is_active) {
 		ctx->is_active = 0;
-		cpuctx->task_ctx = NULL;
+		if (ctx->task) {
+			WARN_ON_ONCE(cpuctx->task_ctx != ctx);
+			cpuctx->task_ctx = NULL;
+		}
 	}
-	raw_spin_unlock(&ctx->lock);
-
-	return 0;
 }
 
 /*
  * Remove the event from a task's (or a CPU's) list of events.
  *
- * CPU events are removed with a smp call. For task events we only
- * call when the task is on a CPU.
- *
  * If event->ctx is a cloned context, callers must make sure that
  * every task struct that event->ctx->task could possibly point to
  * remains valid.  This is OK when called from perf_release since
@@ -1711,73 +1774,32 @@ static int __perf_remove_from_context(void *info)
  * When called from perf_event_exit_task, it's OK because the
  * context has been detached from its task.
  */
-static void perf_remove_from_context(struct perf_event *event, bool detach_group)
+static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
 {
-	struct perf_event_context *ctx = event->ctx;
-	struct remove_event re = {
-		.event = event,
-		.detach_group = detach_group,
-	};
+	lockdep_assert_held(&event->ctx->mutex);
 
-	lockdep_assert_held(&ctx->mutex);
-
-	event_function_call(event, __perf_remove_from_context,
-			    ___perf_remove_from_context, &re);
+	event_function_call(event, __perf_remove_from_context, (void *)flags);
 }
 
 /*
  * Cross CPU call to disable a performance event
  */
-int __perf_event_disable(void *info)
-{
-	struct perf_event *event = info;
-	struct perf_event_context *ctx = event->ctx;
-	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
-
-	/*
-	 * If this is a per-task event, need to check whether this
-	 * event's task is the current task on this cpu.
-	 *
-	 * Can trigger due to concurrent perf_event_context_sched_out()
-	 * flipping contexts around.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx)
-		return -EINVAL;
-
-	raw_spin_lock(&ctx->lock);
-
-	/*
-	 * If the event is on, turn it off.
-	 * If it is in error state, leave it in error state.
-	 */
-	if (event->state >= PERF_EVENT_STATE_INACTIVE) {
-		update_context_time(ctx);
-		update_cgrp_time_from_event(event);
-		update_group_times(event);
-		if (event == event->group_leader)
-			group_sched_out(event, cpuctx, ctx);
-		else
-			event_sched_out(event, cpuctx, ctx);
-		event->state = PERF_EVENT_STATE_OFF;
-	}
-
-	raw_spin_unlock(&ctx->lock);
-
-	return 0;
-}
-
-void ___perf_event_disable(void *info)
+static void __perf_event_disable(struct perf_event *event,
+				 struct perf_cpu_context *cpuctx,
+				 struct perf_event_context *ctx,
+				 void *info)
 {
-	struct perf_event *event = info;
+	if (event->state < PERF_EVENT_STATE_INACTIVE)
+		return;
 
-	/*
-	 * Since we have the lock this context can't be scheduled
-	 * in, so we can change the state safely.
-	 */
-	if (event->state == PERF_EVENT_STATE_INACTIVE) {
-		update_group_times(event);
-		event->state = PERF_EVENT_STATE_OFF;
-	}
+	update_context_time(ctx);
+	update_cgrp_time_from_event(event);
+	update_group_times(event);
+	if (event == event->group_leader)
+		group_sched_out(event, cpuctx, ctx);
+	else
+		event_sched_out(event, cpuctx, ctx);
+	event->state = PERF_EVENT_STATE_OFF;
 }
 
 /*
@@ -1788,7 +1810,8 @@ void ___perf_event_disable(void *info)
  * remains valid.  This condition is satisifed when called through
  * perf_event_for_each_child or perf_event_for_each because they
  * hold the top-level event's child_mutex, so any descendant that
- * goes to exit will block in sync_child_event.
+ * goes to exit will block in perf_event_exit_event().
+ *
  * When called from perf_pending_event it's OK because event->ctx
  * is the current context on this CPU and preemption is disabled,
  * hence we can't get into perf_event_task_sched_out for this context.
@@ -1804,8 +1827,12 @@ static void _perf_event_disable(struct perf_event *event)
 	}
 	raw_spin_unlock_irq(&ctx->lock);
 
-	event_function_call(event, __perf_event_disable,
-			    ___perf_event_disable, event);
+	event_function_call(event, __perf_event_disable, NULL);
+}
+
+void perf_event_disable_local(struct perf_event *event)
+{
+	event_function_local(event, __perf_event_disable, NULL);
 }
 
 /*
@@ -1918,9 +1945,6 @@ event_sched_in(struct perf_event *event,
 	if (event->attr.exclusive)
 		cpuctx->exclusive = 1;
 
-	if (is_orphaned_child(event))
-		schedule_orphans_remove(ctx);
-
 out:
 	perf_pmu_enable(event->pmu);
 
@@ -2039,7 +2063,8 @@ static void add_event_to_ctx(struct perf_event *event,
 	event->tstamp_stopped = tstamp;
 }
 
-static void task_ctx_sched_out(struct perf_event_context *ctx);
+static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
+			       struct perf_event_context *ctx);
 static void
 ctx_sched_in(struct perf_event_context *ctx,
 	     struct perf_cpu_context *cpuctx,
@@ -2058,16 +2083,15 @@ static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
 		ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
 }
 
-static void ___perf_install_in_context(void *info)
+static void ctx_resched(struct perf_cpu_context *cpuctx,
+			struct perf_event_context *task_ctx)
 {
-	struct perf_event *event = info;
-	struct perf_event_context *ctx = event->ctx;
-
-	/*
-	 * Since the task isn't running, its safe to add the event, us holding
-	 * the ctx->lock ensures the task won't get scheduled in.
-	 */
-	add_event_to_ctx(event, ctx);
+	perf_pmu_disable(cpuctx->ctx.pmu);
+	if (task_ctx)
+		task_ctx_sched_out(cpuctx, task_ctx);
+	cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+	perf_event_sched_in(cpuctx, task_ctx, current);
+	perf_pmu_enable(cpuctx->ctx.pmu);
 }
 
 /*
@@ -2077,55 +2101,31 @@ static void ___perf_install_in_context(void *info)
  */
 static int  __perf_install_in_context(void *info)
 {
-	struct perf_event *event = info;
-	struct perf_event_context *ctx = event->ctx;
+	struct perf_event_context *ctx = info;
 	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
 	struct perf_event_context *task_ctx = cpuctx->task_ctx;
-	struct task_struct *task = current;
-
-	perf_ctx_lock(cpuctx, task_ctx);
-	perf_pmu_disable(cpuctx->ctx.pmu);
-
-	/*
-	 * If there was an active task_ctx schedule it out.
-	 */
-	if (task_ctx)
-		task_ctx_sched_out(task_ctx);
 
-	/*
-	 * If the context we're installing events in is not the
-	 * active task_ctx, flip them.
-	 */
-	if (ctx->task && task_ctx != ctx) {
-		if (task_ctx)
-			raw_spin_unlock(&task_ctx->lock);
+	raw_spin_lock(&cpuctx->ctx.lock);
+	if (ctx->task) {
 		raw_spin_lock(&ctx->lock);
+		/*
+		 * If we hit the 'wrong' task, we've since scheduled and
+		 * everything should be sorted, nothing to do!
+		 */
 		task_ctx = ctx;
-	}
+		if (ctx->task != current)