ring-buffer: Micro-optimize with some strategic inlining

By using inline and noinline, we are able to make the fast path of
recording an event 4% faster.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 15 insertions, 8 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d9f3e7a82137..f5007d0d932d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2078,7 +2078,7 @@ static void rb_start_commit(struct ring_buffer_per_cpu *cpu_buffer)
         local_inc(&cpu_buffer->commits);
 }
 
-static void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer)
+static inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer)
 {
         unsigned long commits;
 
@@ -2193,13 +2193,9 @@ rb_reserve_next_event(struct ring_buffer *buffer,
 
 #define TRACE_RECURSIVE_DEPTH 16
 
-static int trace_recursive_lock(void)
+/* Keep this code out of the fast path cache */
+static noinline void trace_recursive_fail(void)
 {
-        current->trace_recursion++;
-
-        if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
-                return 0;
-
         /* Disable all tracing before we do anything else */
         tracing_off_permanent();
 
@@ -2211,10 +2207,21 @@ static int trace_recursive_lock(void)
                     in_nmi());
 
         WARN_ON_ONCE(1);
+}
+
+static inline int trace_recursive_lock(void)
+{
+        current->trace_recursion++;
+
+        if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
+                return 0;
+
+        trace_recursive_fail();
+
         return -1;
 }
 
-static void trace_recursive_unlock(void)
+static inline void trace_recursive_unlock(void)
 {
         WARN_ON_ONCE(!current->trace_recursion);