Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

1 files changed, 44 insertions, 11 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1ce6208fd727..a2d13e8c8fd8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -155,13 +155,6 @@ ns2usecs(cycle_t nsec)
         return nsec;
 }
 
-cycle_t ftrace_now(int cpu)
-{
-        u64 ts = ring_buffer_time_stamp(cpu);
-        ring_buffer_normalize_time_stamp(cpu, &ts);
-        return ts;
-}
-
 /*
  * The global_trace is the descriptor that holds the tracing
  * buffers for the live tracing. For each CPU, it contains
@@ -178,6 +171,20 @@ static struct trace_array	global_trace;
 
 static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
 
+cycle_t ftrace_now(int cpu)
+{
+        u64 ts;
+
+        /* Early boot up does not have a buffer yet */
+        if (!global_trace.buffer)
+                return trace_clock_local();
+
+        ts = ring_buffer_time_stamp(global_trace.buffer, cpu);
+        ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts);
+
+        return ts;
+}
+
 /*
  * The max_tr is used to snapshot the global_trace when a maximum
  * latency is reached. Some tracers will use this to store a maximum
@@ -308,6 +315,7 @@ static const char *trace_options[] = {
         "printk-msg-only",
         "context-info",
         "latency-format",
+        "global-clock",
         NULL
 };
 
@@ -2244,6 +2252,34 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
         return 0;
 }
 
+static void set_tracer_flags(unsigned int mask, int enabled)
+{
+        /* do nothing if flag is already set */
+        if (!!(trace_flags & mask) == !!enabled)
+                return;
+
+        if (enabled)
+                trace_flags |= mask;
+        else
+                trace_flags &= ~mask;
+
+        if (mask == TRACE_ITER_GLOBAL_CLK) {
+                u64 (*func)(void);
+
+                if (enabled)
+                        func = trace_clock_global;
+                else
+                        func = trace_clock_local;
+
+                mutex_lock(&trace_types_lock);
+                ring_buffer_set_clock(global_trace.buffer, func);
+
+                if (max_tr.buffer)
+                        ring_buffer_set_clock(max_tr.buffer, func);
+                mutex_unlock(&trace_types_lock);
+        }
+}
+
 static ssize_t
 tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                         size_t cnt, loff_t *ppos)
@@ -2271,10 +2307,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                 int len = strlen(trace_options[i]);
 
                 if (strncmp(cmp, trace_options[i], len) == 0) {
-                        if (neg)
-                                trace_flags &= ~(1 << i);
-                        else
-                                trace_flags |= (1 << i);
+                        set_tracer_flags(1 << i, !neg);
                         break;
                 }
         }