These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / kernel / trace / trace_branch.c

diff --git a/kernel/kernel/trace/trace_branch.c b/kernel/kernel/trace/trace_branch.c
index 57cbf1e..3a2a737 100644 (file)
--- a/kernel/kernel/trace/trace_branch.c
+++ b/kernel/kernel/trace/trace_branch.c
@@ -29,16 +29,19 @@ static struct trace_array *branch_tracer;
 static void
 probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 {
-       struct ftrace_event_call *call = &event_branch;
+       struct trace_event_call *call = &event_branch;
        struct trace_array *tr = branch_tracer;
        struct trace_array_cpu *data;
        struct ring_buffer_event *event;
        struct trace_branch *entry;
        struct ring_buffer *buffer;
        unsigned long flags;
-       int cpu, pc;
+       int pc;
        const char *p;
 
+       if (current->trace_recursion & TRACE_BRANCH_BIT)
+               return;
+
        /*
         * I would love to save just the ftrace_likely_data pointer, but
         * this code can also be used by modules. Ugly things can happen
@@ -49,10 +52,10 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
        if (unlikely(!tr))
                return;
 
-       local_irq_save(flags);
-       cpu = raw_smp_processor_id();
-       data = per_cpu_ptr(tr->trace_buffer.data, cpu);
-       if (atomic_inc_return(&data->disabled) != 1)
+       raw_local_irq_save(flags);
+       current->trace_recursion |= TRACE_BRANCH_BIT;
+       data = this_cpu_ptr(tr->trace_buffer.data);
+       if (atomic_read(&data->disabled))
                goto out;
 
        pc = preempt_count();
@@ -81,8 +84,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
                __buffer_unlock_commit(buffer, event);
 
  out:
-       atomic_dec(&data->disabled);
-       local_irq_restore(flags);
+       current->trace_recursion &= ~TRACE_BRANCH_BIT;
+       raw_local_irq_restore(flags);
 }
 
 static inline
@@ -122,25 +125,14 @@ void disable_branch_tracing(void)
        mutex_unlock(&branch_tracing_mutex);
 }
 
-static void start_branch_trace(struct trace_array *tr)
-{
-       enable_branch_tracing(tr);
-}
-
-static void stop_branch_trace(struct trace_array *tr)
-{
-       disable_branch_tracing();
-}
-
 static int branch_trace_init(struct trace_array *tr)
 {
-       start_branch_trace(tr);
-       return 0;
+       return enable_branch_tracing(tr);
 }
 
 static void branch_trace_reset(struct trace_array *tr)
 {
-       stop_branch_trace(tr);
+       disable_branch_tracing();
 }
 
 static enum print_line_t trace_branch_print(struct trace_iterator *iter,
@@ -191,7 +183,7 @@ __init static int init_branch_tracer(void)
 {
        int ret;
 
-       ret = register_ftrace_event(&trace_branch_event);
+       ret = register_trace_event(&trace_branch_event);
        if (!ret) {
                printk(KERN_WARNING "Warning: could not register "
                                    "branch events\n");