[patch 04/16] Markers use rcu_*_sched_notrace and notrace

[Mathieu Desnoyers]

Make marker critical code use notrace (__attribute__((no_instrument_function))
to make sure they can be used as an ftrace callback.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
CC: 'Peter Zijlstra' <peterz@xxxxxxxxxxxxx>
CC: "Frank Ch. Eigler" <fche@xxxxxxxxxx>
CC: 'Ingo Molnar' <mingo@xxxxxxx>
CC: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
CC: 'Hideo AOKI' <haoki@xxxxxxxxxx>
CC: Takashi Nishiie <t-nishiie@xxxxxxxxxxxxxxxxxx>
CC: 'Steven Rostedt' <rostedt@xxxxxxxxxxx>
---
 kernel/marker.c |   16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

Index: linux-2.6-lttng/kernel/marker.c
===================================================================
--- linux-2.6-lttng.orig/kernel/marker.c	2008-10-15 09:43:15.000000000 -0400
+++ linux-2.6-lttng/kernel/marker.c	2008-10-15 09:44:08.000000000 -0400
@@ -81,7 +81,7 @@ struct marker_entry {
  * though the function pointer change and the marker enabling are two distinct
  * operations that modifies the execution flow of preemptible code.
  */
-void __mark_empty_function(void *probe_private, void *call_private,
+notrace void __mark_empty_function(void *probe_private, void *call_private,
 	const char *fmt, va_list *args)
 {
 }
@@ -97,7 +97,8 @@ EXPORT_SYMBOL_GPL(__mark_empty_function)
  * need to put a full smp_rmb() in this branch. This is why we do not use
  * rcu_dereference() for the pointer read.
  */
-void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
+notrace void marker_probe_cb(const struct marker *mdata,
+		void *call_private, ...)
 {
 	va_list args;
 	char ptype;
@@ -107,7 +108,7 @@ void marker_probe_cb(const struct marker
 	 * sure the teardown of the callbacks can be done correctly when they
 	 * are in modules and they insure RCU read coherency.
 	 */
-	rcu_read_lock_sched();
+	rcu_read_lock_sched_notrace();
 	ptype = mdata->ptype;
 	if (likely(!ptype)) {
 		marker_probe_func *func;
@@ -145,7 +146,7 @@ void marker_probe_cb(const struct marker
 			va_end(args);
 		}
 	}
-	rcu_read_unlock_sched();
+	rcu_read_unlock_sched_notrace();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb);
 
@@ -157,12 +158,13 @@ EXPORT_SYMBOL_GPL(marker_probe_cb);
  *
  * Should be connected to markers "MARK_NOARGS".
  */
-static void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
+static notrace void marker_probe_cb_noarg(const struct marker *mdata,
+		void *call_private, ...)
 {
 	va_list args;	/* not initialized */
 	char ptype;
 
-	rcu_read_lock_sched();
+	rcu_read_lock_sched_notrace();
 	ptype = mdata->ptype;
 	if (likely(!ptype)) {
 		marker_probe_func *func;
@@ -195,7 +197,7 @@ static void marker_probe_cb_noarg(const 
 			multi[i].func(multi[i].probe_private, call_private,
 				mdata->format, &args);
 	}
-	rcu_read_unlock_sched();
+	rcu_read_unlock_sched_notrace();
 }
 
 static void free_old_closure(struct rcu_head *head)

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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