1 files changed, 55 insertions, 50 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 4393b9e73740..3d1552d3c12b 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -15,6 +15,7 @@
 #include <linux/smp.h>
 #include <linux/file.h>
 #include <linux/poll.h>
+#include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/dcache.h>
 #include <linux/percpu.h>
@@ -81,10 +82,6 @@ extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event)
 void __weak hw_perf_disable(void)               { barrier(); }
 void __weak hw_perf_enable(void)                { barrier(); }
 
-void __weak hw_perf_event_setup(int cpu)        { barrier(); }
-void __weak hw_perf_event_setup_online(int cpu) { barrier(); }
-void __weak hw_perf_event_setup_offline(int cpu)        { barrier(); }
-
 int __weak
 hw_perf_group_sched_in(struct perf_event *group_leader,
                struct perf_cpu_context *cpuctx,
@@ -97,25 +94,15 @@ void __weak perf_event_print_debug(void)	{ }
 
 static DEFINE_PER_CPU(int, perf_disable_count);
 
-void __perf_disable(void)
-{
-        __get_cpu_var(perf_disable_count)++;
-}
-
-bool __perf_enable(void)
-{
-        return !--__get_cpu_var(perf_disable_count);
-}
-
 void perf_disable(void)
 {
-        __perf_disable();
-        hw_perf_disable();
+        if (!__get_cpu_var(perf_disable_count)++)
+                hw_perf_disable();
 }
 
 void perf_enable(void)
 {
-        if (__perf_enable())
+        if (!--__get_cpu_var(perf_disable_count))
                 hw_perf_enable();
 }
 
@@ -1178,11 +1165,9 @@ void perf_event_task_sched_out(struct task_struct *task,
         struct perf_event_context *ctx = task->perf_event_ctxp;
         struct perf_event_context *next_ctx;
         struct perf_event_context *parent;
-        struct pt_regs *regs;
         int do_switch = 1;
 
-        regs = task_pt_regs(task);
-        perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
+        perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
 
         if (likely(!ctx || !cpuctx->task_ctx))
                 return;
@@ -1538,12 +1523,15 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
                  */
                 if (interrupts == MAX_INTERRUPTS) {
                         perf_log_throttle(event, 1);
+                        perf_disable();
                         event->pmu->unthrottle(event);
+                        perf_enable();
                 }
 
                 if (!event->attr.freq || !event->attr.sample_freq)
                         continue;
 
+                perf_disable();
                 event->pmu->read(event);
                 now = atomic64_read(&event->count);
                 delta = now - hwc->freq_count_stamp;
@@ -1551,6 +1539,7 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
 
                 if (delta > 0)
                         perf_adjust_period(event, TICK_NSEC, delta);
+                perf_enable();
         }
         raw_spin_unlock(&ctx->lock);
 }
@@ -1560,9 +1549,6 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
  */
 static void rotate_ctx(struct perf_event_context *ctx)
 {
-        if (!ctx->nr_events)
-                return;
-
         raw_spin_lock(&ctx->lock);
 
         /* Rotate the first entry last of non-pinned groups */
@@ -1575,19 +1561,28 @@ void perf_event_task_tick(struct task_struct *curr)
 {
         struct perf_cpu_context *cpuctx;
         struct perf_event_context *ctx;
+        int rotate = 0;
 
         if (!atomic_read(&nr_events))
                 return;
 
         cpuctx = &__get_cpu_var(perf_cpu_context);
-        ctx = curr->perf_event_ctxp;
+        if (cpuctx->ctx.nr_events &&
+            cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
+                rotate = 1;
 
-        perf_disable();
+        ctx = curr->perf_event_ctxp;
+        if (ctx && ctx->nr_events && ctx->nr_events != ctx->nr_active)
+                rotate = 1;
 
         perf_ctx_adjust_freq(&cpuctx->ctx);
         if (ctx)
                 perf_ctx_adjust_freq(ctx);
 
+        if (!rotate)
+                return;
+
+        perf_disable();
         cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
         if (ctx)
                 task_ctx_sched_out(ctx, EVENT_FLEXIBLE);
@@ -1599,7 +1594,6 @@ void perf_event_task_tick(struct task_struct *curr)
         cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE);
         if (ctx)
                 task_ctx_sched_in(curr, EVENT_FLEXIBLE);
-
         perf_enable();
 }
 
@@ -2791,6 +2785,12 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
         return NULL;
 }
 
+__weak
+void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
+{
+}
+
+
 /*
  * Output
  */
@@ -3376,15 +3376,23 @@ static void perf_event_task_output(struct perf_event *event,
                                      struct perf_task_event *task_event)
 {
         struct perf_output_handle handle;
-        int size;
         struct task_struct *task = task_event->task;
-        int ret;
+        unsigned long flags;
+        int size, ret;
+
+        /*
+         * If this CPU attempts to acquire an rq lock held by a CPU spinning
+         * in perf_output_lock() from interrupt context, it's game over.
+         */
+        local_irq_save(flags);
 
         size  = task_event->event_id.header.size;
         ret = perf_output_begin(&handle, event, size, 0, 0);
 
-        if (ret)
+        if (ret) {
+                local_irq_restore(flags);
                 return;
+        }
 
         task_event->event_id.pid = perf_event_pid(event, task);
         task_event->event_id.ppid = perf_event_pid(event, current);
@@ -3395,6 +3403,7 @@ static void perf_event_task_output(struct perf_event *event,
         perf_output_put(&handle, task_event->event_id);
 
         perf_output_end(&handle);
+        local_irq_restore(flags);
 }
 
 static int perf_event_task_match(struct perf_event *event)
@@ -4318,9 +4327,8 @@ static const struct pmu perf_ops_task_clock = {
 #ifdef CONFIG_EVENT_TRACING
 
 void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
-                          int entry_size)
+                   int entry_size, struct pt_regs *regs)
 {
-        struct pt_regs *regs = get_irq_regs();
         struct perf_sample_data data;
         struct perf_raw_record raw = {
                 .size = entry_size,
@@ -4330,12 +4338,9 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
         perf_sample_data_init(&data, addr);
         data.raw = &raw;
 
-        if (!regs)
-                regs = task_pt_regs(current);
-
         /* Trace events already protected against recursion */
         do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
-                                &data, regs);
+                         &data, regs);
 }
 EXPORT_SYMBOL_GPL(perf_tp_event);
 
@@ -4351,7 +4356,7 @@ static int perf_tp_event_match(struct perf_event *event,
 
 static void tp_perf_event_destroy(struct perf_event *event)
 {
-        ftrace_profile_disable(event->attr.config);
+        perf_trace_disable(event->attr.config);
 }
 
 static const struct pmu *tp_perf_event_init(struct perf_event *event)
@@ -4365,7 +4370,7 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event)
                         !capable(CAP_SYS_ADMIN))
                 return ERR_PTR(-EPERM);
 
-        if (ftrace_profile_enable(event->attr.config))
+        if (perf_trace_enable(event->attr.config))
                 return NULL;
 
         event->destroy = tp_perf_event_destroy;
@@ -4892,7 +4897,7 @@ err_fput_free_put_context:
 
 err_free_put_context:
         if (err < 0)
-                kfree(event);
+                free_event(event);
 
 err_put_context:
         if (err < 0)
@@ -5372,18 +5377,26 @@ int perf_event_init_task(struct task_struct *child)
         return ret;
 }
 
+static void __init perf_event_init_all_cpus(void)
+{
+        int cpu;
+        struct perf_cpu_context *cpuctx;
+
+        for_each_possible_cpu(cpu) {
+                cpuctx = &per_cpu(perf_cpu_context, cpu);
+                __perf_event_init_context(&cpuctx->ctx, NULL);
+        }
+}
+
 static void __cpuinit perf_event_init_cpu(int cpu)
 {
         struct perf_cpu_context *cpuctx;
 
         cpuctx = &per_cpu(perf_cpu_context, cpu);
-        __perf_event_init_context(&cpuctx->ctx, NULL);
 
         spin_lock(&perf_resource_lock);
         cpuctx->max_pertask = perf_max_events - perf_reserved_percpu;
         spin_unlock(&perf_resource_lock);
-
-        hw_perf_event_setup(cpu);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -5423,20 +5436,11 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
                 perf_event_init_cpu(cpu);
                 break;
 
-        case CPU_ONLINE:
-        case CPU_ONLINE_FROZEN:
-                hw_perf_event_setup_online(cpu);
-                break;
-
         case CPU_DOWN_PREPARE:
         case CPU_DOWN_PREPARE_FROZEN:
                 perf_event_exit_cpu(cpu);
                 break;
 
-        case CPU_DEAD:
-                hw_perf_event_setup_offline(cpu);
-                break;
-
         default:
                 break;
         }
@@ -5454,6 +5458,7 @@ static struct notifier_block __cpuinitdata perf_cpu_nb = {
 
 void __init perf_event_init(void)
 {
+        perf_event_init_all_cpus();
         perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
                         (void *)(long)smp_processor_id());
         perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,