tracing: Kill the dead code in probe_sched_switch() and probe_sched_wakeup()

After the previous patch it is clear that "tracer_enabled" can never be
true, we can remove the "if (tracer_enabled)" code in probe_sched_switch()
and probe_sched_wakeup(). Plus we can obviously remove tracer_enabled,
ctx_trace, and sched_stopped as well.

Link: http://lkml.kernel.org/p/20140723193503.GA30217@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 3b60301..f7c7f4f 100644 (file)
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -14,12 +14,8 @@
 
 #include "trace.h"
 
-static struct trace_array      *ctx_trace;
-static int __read_mostly       tracer_enabled;
 static int                     sched_ref;
 static DEFINE_MUTEX(sched_register_mutex);
-static int                     sched_stopped;
-
 
 void
 tracing_sched_switch_trace(struct trace_array *tr,
@@ -52,29 +48,11 @@ tracing_sched_switch_trace(struct trace_array *tr,
 static void
 probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *next)
 {
-       struct trace_array_cpu *data;
-       unsigned long flags;
-       int cpu;
-       int pc;
-
        if (unlikely(!sched_ref))
                return;
 
        tracing_record_cmdline(prev);
        tracing_record_cmdline(next);
-
-       if (!tracer_enabled || sched_stopped)
-               return;
-
-       pc = preempt_count();
-       local_irq_save(flags);
-       cpu = raw_smp_processor_id();
-       data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu);
-
-       if (likely(!atomic_read(&data->disabled)))
-               tracing_sched_switch_trace(ctx_trace, prev, next, flags, pc);
-
-       local_irq_restore(flags);
 }
 
 void
@@ -108,28 +86,10 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 static void
 probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success)
 {
-       struct trace_array_cpu *data;
-       unsigned long flags;
-       int cpu, pc;
-
        if (unlikely(!sched_ref))
                return;
 
        tracing_record_cmdline(current);
-
-       if (!tracer_enabled || sched_stopped)
-               return;
-
-       pc = preempt_count();
-       local_irq_save(flags);
-       cpu = raw_smp_processor_id();
-       data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu);
-
-       if (likely(!atomic_read(&data->disabled)))
-               tracing_sched_wakeup_trace(ctx_trace, wakee, current,
-                                          flags, pc);
-
-       local_irq_restore(flags);
 }
 
 static int tracing_sched_register(void)