1 files changed, 2 insertions, 42 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4fb10ef727d3..48ef4960ec90 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -87,18 +87,6 @@ static int tracing_disabled = 1;
 
 DEFINE_PER_CPU(int, ftrace_cpu_disabled);
 
-static inline void ftrace_disable_cpu(void)
-{
-        preempt_disable();
-        __this_cpu_inc(ftrace_cpu_disabled);
-}
-
-static inline void ftrace_enable_cpu(void)
-{
-        __this_cpu_dec(ftrace_cpu_disabled);
-        preempt_enable();
-}
-
 cpumask_var_t __read_mostly     tracing_buffer_mask;
 
 /*
@@ -748,8 +736,6 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 
         arch_spin_lock(&ftrace_max_lock);
 
-        ftrace_disable_cpu();
-
         ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
 
         if (ret == -EBUSY) {
@@ -763,8 +749,6 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
                         "Failed to swap buffers due to commit in progress\n");
         }
 
-        ftrace_enable_cpu();
-
         WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
 
         __update_max_tr(tr, tsk, cpu);
@@ -916,13 +900,6 @@ out:
         mutex_unlock(&trace_types_lock);
 }
 
-static void __tracing_reset(struct ring_buffer *buffer, int cpu)
-{
-        ftrace_disable_cpu();
-        ring_buffer_reset_cpu(buffer, cpu);
-        ftrace_enable_cpu();
-}
-
 void tracing_reset(struct trace_array *tr, int cpu)
 {
         struct ring_buffer *buffer = tr->buffer;
@@ -931,7 +908,7 @@ void tracing_reset(struct trace_array *tr, int cpu)
 
         /* Make sure all commits have finished */
         synchronize_sched();
-        __tracing_reset(buffer, cpu);
+        ring_buffer_reset_cpu(buffer, cpu);
 
         ring_buffer_record_enable(buffer);
 }
@@ -949,7 +926,7 @@ void tracing_reset_online_cpus(struct trace_array *tr)
         tr->time_start = ftrace_now(tr->cpu);
 
         for_each_online_cpu(cpu)
-                __tracing_reset(buffer, cpu);
+                ring_buffer_reset_cpu(buffer, cpu);
 
         ring_buffer_record_enable(buffer);
 }
@@ -1733,14 +1710,9 @@ EXPORT_SYMBOL_GPL(trace_vprintk);
 
 static void trace_iterator_increment(struct trace_iterator *iter)
 {
-        /* Don't allow ftrace to trace into the ring buffers */
-        ftrace_disable_cpu();
-
         iter->idx++;
         if (iter->buffer_iter[iter->cpu])
                 ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
-
-        ftrace_enable_cpu();
 }
 
 static struct trace_entry *
@@ -1750,17 +1722,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
         struct ring_buffer_event *event;
         struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
 
-        /* Don't allow ftrace to trace into the ring buffers */
-        ftrace_disable_cpu();
-
         if (buf_iter)
                 event = ring_buffer_iter_peek(buf_iter, ts);
         else
                 event = ring_buffer_peek(iter->tr->buffer, cpu, ts,
                                          lost_events);
 
-        ftrace_enable_cpu();
-
         if (event) {
                 iter->ent_size = ring_buffer_event_length(event);
                 return ring_buffer_event_data(event);
@@ -1850,11 +1817,8 @@ void *trace_find_next_entry_inc(struct trace_iterator *iter)
 
 static void trace_consume(struct trace_iterator *iter)
 {
-        /* Don't allow ftrace to trace into the ring buffers */
-        ftrace_disable_cpu();
         ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts,
                             &iter->lost_events);
-        ftrace_enable_cpu();
 }
 
 static void *s_next(struct seq_file *m, void *v, loff_t *pos)
@@ -1943,16 +1907,12 @@ static void *s_start(struct seq_file *m, loff_t *pos)
                 iter->cpu = 0;
                 iter->idx = -1;
 
-                ftrace_disable_cpu();
-
                 if (cpu_file == TRACE_PIPE_ALL_CPU) {
                         for_each_tracing_cpu(cpu)
                                 tracing_iter_reset(iter, cpu);
                 } else
                         tracing_iter_reset(iter, cpu_file);
 
-                ftrace_enable_cpu();
-
                 iter->leftover = 0;
                 for (p = iter; p && l < *pos; p = s_next(m, p, &l))
                         ;