[PATCH 0/2][GIT PULL][v2.6.34] tracing: fixes

[PATCH 0/2][GIT PULL][v2.6.34] tracing: fixes

[Steven Rostedt]

Ingo,

Please pull the latest tip/tracing/urgent tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/tracing/urgent


Li Zefan (2):
      tracing: Reduce overhead of module tracepoints
      tracing: Fix lockdep warning in global_clock()

----
 include/linux/module.h        |    6 ++----
 include/trace/events/module.h |   14 +++++++-------
 kernel/module.c               |    3 +--
 kernel/trace/trace_clock.c    |    4 ++--
 4 files changed, 12 insertions(+), 15 deletions(-)

[PATCH 1/2] tracing: Reduce overhead of module tracepoints

[Steven Rostedt]

[-- Attachment #1: 0001-tracing-Reduce-overhead-of-module-tracepoints.patch --]
[-- Type: text/plain, Size: 3198 bytes --]

From: Li Zefan <lizf@cn.fujitsu.com>

Remove the @refcnt argument, because it has side-effects, and
arguments with side-effects are not skipped by the jump over
disabled instrumentation, so it adds overhead even when the
tracepoints are disabled.

Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FA7.6040406@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/module.h        |    6 ++----
 include/trace/events/module.h |   14 +++++++-------
 kernel/module.c               |    3 +--
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 5e869ff..393ec39 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -460,8 +460,7 @@ static inline void __module_get(struct module *module)
 	if (module) {
 		preempt_disable();
 		__this_cpu_inc(module->refptr->count);
-		trace_module_get(module, _THIS_IP_,
-				 __this_cpu_read(module->refptr->count));
+		trace_module_get(module, _THIS_IP_);
 		preempt_enable();
 	}
 }
@@ -475,8 +474,7 @@ static inline int try_module_get(struct module *module)
 
 		if (likely(module_is_live(module))) {
 			__this_cpu_inc(module->refptr->count);
-			trace_module_get(module, _THIS_IP_,
-				__this_cpu_read(module->refptr->count));
+			trace_module_get(module, _THIS_IP_);
 		}
 		else
 			ret = 0;
diff --git a/include/trace/events/module.h b/include/trace/events/module.h
index 4b0f48b..a585f81 100644
--- a/include/trace/events/module.h
+++ b/include/trace/events/module.h
@@ -53,9 +53,9 @@ TRACE_EVENT(module_free,
 
 DECLARE_EVENT_CLASS(module_refcnt,
 
-	TP_PROTO(struct module *mod, unsigned long ip, int refcnt),
+	TP_PROTO(struct module *mod, unsigned long ip),
 
-	TP_ARGS(mod, ip, refcnt),
+	TP_ARGS(mod, ip),
 
 	TP_STRUCT__entry(
 		__field(	unsigned long,	ip		)
@@ -65,7 +65,7 @@ DECLARE_EVENT_CLASS(module_refcnt,
 
 	TP_fast_assign(
 		__entry->ip	= ip;
-		__entry->refcnt	= refcnt;
+		__entry->refcnt	= __this_cpu_read(mod->refptr->count);
 		__assign_str(name, mod->name);
 	),
 
@@ -75,16 +75,16 @@ DECLARE_EVENT_CLASS(module_refcnt,
 
 DEFINE_EVENT(module_refcnt, module_get,
 
-	TP_PROTO(struct module *mod, unsigned long ip, int refcnt),
+	TP_PROTO(struct module *mod, unsigned long ip),
 
-	TP_ARGS(mod, ip, refcnt)
+	TP_ARGS(mod, ip)
 );
 
 DEFINE_EVENT(module_refcnt, module_put,
 
-	TP_PROTO(struct module *mod, unsigned long ip, int refcnt),
+	TP_PROTO(struct module *mod, unsigned long ip),
 
-	TP_ARGS(mod, ip, refcnt)
+	TP_ARGS(mod, ip)
 );
 
 TRACE_EVENT(module_request,
diff --git a/kernel/module.c b/kernel/module.c
index c968d36..21591ad 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -800,8 +800,7 @@ void module_put(struct module *module)
 		preempt_disable();
 		__this_cpu_dec(module->refptr->count);
 
-		trace_module_put(module, _RET_IP_,
-				 __this_cpu_read(module->refptr->count));
+		trace_module_put(module, _RET_IP_);
 		/* Maybe they're waiting for us to drop reference? */
 		if (unlikely(!module_is_live(module)))
 			wake_up_process(module->waiter);
-- 
1.7.0

[PATCH 2/2] tracing: Fix lockdep warning in global_clock()

[Steven Rostedt]

[-- Attachment #1: 0002-tracing-Fix-lockdep-warning-in-global_clock.patch --]
[-- Type: text/plain, Size: 1291 bytes --]

From: Li Zefan <lizf@cn.fujitsu.com>

# echo 1 > events/enable
 # echo global > trace_clock

------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3162 check_flags+0xb2/0x190()
...
---[ end trace 3f86734a89416623 ]---
possible reason: unannotated irqs-on.
...

There's no reason to use the raw_local_irq_save() in trace_clock_global.
The local_irq_save() version is fine, and does not cause the bug in lockdep.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FA1.7030606@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_clock.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 6fbfb8f..9d589d8 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -84,7 +84,7 @@ u64 notrace trace_clock_global(void)
 	int this_cpu;
 	u64 now;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 
 	this_cpu = raw_smp_processor_id();
 	now = cpu_clock(this_cpu);
@@ -110,7 +110,7 @@ u64 notrace trace_clock_global(void)
 	arch_spin_unlock(&trace_clock_struct.lock);
 
  out:
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 
 	return now;
 }
-- 
1.7.0