tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()

This patch changes filter_check_discard() to make use of the new
ring_buffer_discard_commit() function and modifies the current users to
call the old commit function in the non-discard case.

It also introduces a version of filter_check_discard() that uses the
global trace buffer (filter_current_check_discard()) for those cases.

v2 changes:

- fix compile error noticed by Ingo Molnar

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1239178554.10295.36.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 3 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index dfefffd7ae39..9729d14767d8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -866,13 +866,21 @@ extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 extern void filter_free_subsystem_preds(struct event_subsystem *system);
 extern int filter_add_subsystem_pred(struct event_subsystem *system,
                                      struct filter_pred *pred);
+extern int filter_current_check_discard(struct ftrace_event_call *call,
+                                        void *rec,
+                                        struct ring_buffer_event *event);
 
-static inline void
+static inline int
 filter_check_discard(struct ftrace_event_call *call, void *rec,
+                     struct ring_buffer *buffer,
                      struct ring_buffer_event *event)
 {
-        if (unlikely(call->preds) && !filter_match_preds(call, rec))
-                ring_buffer_event_discard(event);
+        if (unlikely(call->preds) && !filter_match_preds(call, rec)) {
+                ring_buffer_discard_commit(buffer, event);
+                return 1;
+        }
+
+        return 0;
 }
 
 #define __common_field(type, item)                                      \