commit d9abde2138e0a00a0d7e44676928efa0ef629d48
author Steven Rostedt <srostedt@redhat.com> Tue Oct 19 13:17:08 2010 -0400
committer Steven Rostedt <rostedt@goodmis.org> Wed Oct 20 15:17:57 2010 -0400
tree 29b75afdf39664debd21c50af5d882856f7fa2a9
parent 140ff89127c74b1b1c1b0152a36ea3720ccf6bc3

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>

kernel/trace/ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d9f3e7a..f5007d0 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2078,7 +2078,7 @@
 	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 @@
 
 #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 @@
 		    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);