ftrace: remove trace array ctrl

Impact: remove obsolete variable in trace_array structure

With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 15 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9e83188172a1..58435415b366 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -537,7 +537,6 @@ int register_tracer(struct tracer *type)
         if (type->selftest) {
                 struct tracer *saved_tracer = current_trace;
                 struct trace_array *tr = &global_trace;
-                int saved_ctrl = tr->ctrl;
                 int i;
                 /*
                  * Run a selftest on this tracer.
@@ -550,13 +549,11 @@ int register_tracer(struct tracer *type)
                         tracing_reset(tr, i);
                 }
                 current_trace = type;
-                tr->ctrl = 0;
                 /* the test is responsible for initializing and enabling */
                 pr_info("Testing tracer %s: ", type->name);
                 ret = type->selftest(type, tr);
                 /* the test is responsible for resetting too */
                 current_trace = saved_tracer;
-                tr->ctrl = saved_ctrl;
                 if (ret) {
                         printk(KERN_CONT "FAILED!\n");
                         goto out;
@@ -966,7 +963,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
         int cpu;
         int pc;
 
-        if (tracing_disabled || !tr->ctrl)
+        if (tracing_disabled)
                 return;
 
         pc = preempt_count();
@@ -2820,7 +2817,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
         unsigned long val;
         char buf[64];
         int ret;
-        struct trace_array *tr = filp->private_data;
 
         if (cnt >= sizeof(buf))
                 return -EINVAL;
@@ -2840,12 +2836,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
         mutex_lock(&trace_types_lock);
 
-        if (tr->ctrl) {
-                cnt = -EBUSY;
-                pr_info("ftrace: please disable tracing"
-                        " before modifying buffer size\n");
-                goto out;
-        }
+        tracing_stop();
 
         if (val != global_trace.entries) {
                 ret = ring_buffer_resize(global_trace.buffer, val);
@@ -2878,6 +2869,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
         if (tracing_disabled)
                 cnt = -ENOMEM;
  out:
+        tracing_start();
         max_tr.entries = global_trace.entries;
         mutex_unlock(&trace_types_lock);
 
@@ -2900,9 +2892,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 {
         char *buf;
         char *end;
-        struct trace_array *tr = &global_trace;
 
-        if (!tr->ctrl || tracing_disabled)
+        if (tracing_disabled)
                 return -EINVAL;
 
         if (cnt > TRACE_BUF_SIZE)
@@ -3131,7 +3122,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
         unsigned long flags, irq_flags;
         int cpu, len = 0, size, pc;
 
-        if (!tr->ctrl || tracing_disabled)
+        if (tracing_disabled)
                 return 0;
 
         pc = preempt_count();
@@ -3365,7 +3356,6 @@ __init static int tracer_alloc_buffers(void)
 #endif
 
         /* All seems OK, enable tracing */
-        global_trace.ctrl = 1;
         tracing_disabled = 0;
 
         atomic_notifier_chain_register(&panic_notifier_list,