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authorSteven Rostedt <srostedt@redhat.com>2012-02-07 09:32:43 -0500
committerSteven Rostedt <rostedt@goodmis.org>2012-02-13 08:23:21 -0500
commit2fbb90db1b8fcc78f43830f1a009f3af243c5f42 (patch)
treea190e127ab6bd352d95a4a0964f0f1e8858cb2f4 /include/linux/tracepoint.h
parentf069686e4bdc60a637d210ea3eea25fcdb82df88 (diff)
tracing/rcu: Add trace_##name##__rcuidle() static tracepoint for inside rcu_idle_exit() sections
Added is a new static inline function that lets *any* tracepoint be used inside a rcu_idle_exit() section. And this also solves the problem where the same tracepoint may be used inside a rcu_idle_exit() section as well as outside of one. I added a new tracepoint function with a "_rcuidle" extension. All tracepoints can be used with either the normal "trace_foobar()" function, or the "trace_foobar_rcuidle()" function when inside a rcu_idle_exit() section. All tracepoints defined by TRACE_EVENT() or any of the derivatives will have a "_rcuidle()" function also defined. When a tracepoint is used within an rcu_idle_exit() section, the "_rcuidle()" version must be used. This denotes that the tracepoint is within rcu_idle_exit() and it allows the rcu read locks within the tracepoint to still be valid, as this version takes us out of rcu_idle_exit(). Another nice aspect about this patch is that "static inline"s are not compiled into text when not used. So only the tracepoints that actually use the _rcuidle() version will have them defined in the actual text that is booted. Link: http://lkml.kernel.org/r/1328563113.2200.39.camel@gandalf.stny.rr.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/tracepoint.h')
-rw-r--r--include/linux/tracepoint.h22
1 files changed, 18 insertions, 4 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index df0a779c1bbd..fc36da97ff7e 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -114,7 +114,7 @@ static inline void tracepoint_synchronize_unregister(void)
* as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just
* "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto".
*/
-#define __DO_TRACE(tp, proto, args, cond) \
+#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu) \
do { \
struct tracepoint_func *it_func_ptr; \
void *it_func; \
@@ -122,6 +122,7 @@ static inline void tracepoint_synchronize_unregister(void)
\
if (!(cond)) \
return; \
+ prercu; \
rcu_read_lock_sched_notrace(); \
it_func_ptr = rcu_dereference_sched((tp)->funcs); \
if (it_func_ptr) { \
@@ -132,6 +133,7 @@ static inline void tracepoint_synchronize_unregister(void)
} while ((++it_func_ptr)->func); \
} \
rcu_read_unlock_sched_notrace(); \
+ postrcu; \
} while (0)
/*
@@ -139,7 +141,7 @@ static inline void tracepoint_synchronize_unregister(void)
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*/
-#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
@@ -147,7 +149,17 @@ static inline void tracepoint_synchronize_unregister(void)
__DO_TRACE(&__tracepoint_##name, \
TP_PROTO(data_proto), \
TP_ARGS(data_args), \
- TP_CONDITION(cond)); \
+ TP_CONDITION(cond),,); \
+ } \
+ static inline void trace_##name##_rcuidle(proto) \
+ { \
+ if (static_branch(&__tracepoint_##name.key)) \
+ __DO_TRACE(&__tracepoint_##name, \
+ TP_PROTO(data_proto), \
+ TP_ARGS(data_args), \
+ TP_CONDITION(cond), \
+ rcu_idle_exit(), \
+ rcu_idle_enter()); \
} \
static inline int \
register_trace_##name(void (*probe)(data_proto), void *data) \
@@ -190,9 +202,11 @@ static inline void tracepoint_synchronize_unregister(void)
EXPORT_SYMBOL(__tracepoint_##name)
#else /* !CONFIG_TRACEPOINTS */
-#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
static inline void trace_##name(proto) \
{ } \
+ static inline void trace_##name##_rcuidle(proto) \
+ { } \
static inline int \
register_trace_##name(void (*probe)(data_proto), \
void *data) \