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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Mathieu Desnoyers <compudj@krystal.dyndns.org>,
	Andi Kleen <andi@firstfloor.org>, Jason Baron <jbaron@redhat.com>,
	David Miller <davem@davemloft.net>
Subject: [PATCH 06/11] jump label: Tracepoint support for jump labels
Date: Wed, 22 Sep 2010 23:49:16 -0400	[thread overview]
Message-ID: <20100923035608.884988118@goodmis.org> (raw)
In-Reply-To: <20100923034910.867858597@goodmis.org>

[-- Attachment #1: 0006-jump-label-Tracepoint-support-for-jump-labels.patch --]
[-- Type: text/plain, Size: 2264 bytes --]

From: Jason Baron <jbaron@redhat.com>

Make use of the jump label infrastructure for tracepoints.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/tracepoint.h |    5 ++++-
 kernel/tracepoint.c        |   14 ++++++++++++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 103d1b6..a4a90b6 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/rcupdate.h>
+#include <linux/jump_label.h>
 
 struct module;
 struct tracepoint;
@@ -145,7 +146,9 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin,
 	extern struct tracepoint __tracepoint_##name;			\
 	static inline void trace_##name(proto)				\
 	{								\
-		if (unlikely(__tracepoint_##name.state))		\
+		JUMP_LABEL(&__tracepoint_##name.state, do_trace);	\
+		return;							\
+do_trace:								\
 			__DO_TRACE(&__tracepoint_##name,		\
 				TP_PROTO(data_proto),			\
 				TP_ARGS(data_args));			\
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index c77f3ec..d6073a5 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -25,6 +25,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/jump_label.h>
 
 extern struct tracepoint __start___tracepoints[];
 extern struct tracepoint __stop___tracepoints[];
@@ -263,7 +264,13 @@ static void set_tracepoint(struct tracepoint_entry **entry,
 	 * is used.
 	 */
 	rcu_assign_pointer(elem->funcs, (*entry)->funcs);
-	elem->state = active;
+	if (!elem->state && active) {
+		enable_jump_label(&elem->state);
+		elem->state = active;
+	} else if (elem->state && !active) {
+		disable_jump_label(&elem->state);
+		elem->state = active;
+	}
 }
 
 /*
@@ -277,7 +284,10 @@ static void disable_tracepoint(struct tracepoint *elem)
 	if (elem->unregfunc && elem->state)
 		elem->unregfunc();
 
-	elem->state = 0;
+	if (elem->state) {
+		disable_jump_label(&elem->state);
+		elem->state = 0;
+	}
 	rcu_assign_pointer(elem->funcs, NULL);
 }
 
-- 
1.7.1



  parent reply	other threads:[~2010-09-23  3:56 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-23  3:49 [GIT PULL] jump label: add jump label code Steven Rostedt
2010-09-23  3:49 ` [PATCH 01/11] jump label: Make dynamic no-op selection available outside of ftrace Steven Rostedt
2010-09-23  3:49 ` [PATCH 02/11] jump label: Make text_poke_early() globally visible Steven Rostedt
2010-09-23  3:49 ` [PATCH 03/11] jump label: Base patch for jump label Steven Rostedt
2010-09-23 14:37   ` Mathieu Desnoyers
2010-09-23 15:39     ` Jason Baron
2010-09-23 15:48       ` Mathieu Desnoyers
2010-09-23 18:40         ` Jason Baron
2010-09-23 18:55           ` Mathieu Desnoyers
2010-09-23 19:08             ` Mathieu Desnoyers
2010-09-23 19:11             ` Jason Baron
2010-09-24  0:44           ` Rusty Russell
2010-09-24 13:54           ` Steven Rostedt
2010-09-24 20:54             ` Mathieu Desnoyers
2010-09-24 21:45               ` Jason Baron
2010-09-23 16:52       ` Steven Rostedt
2010-09-23 17:09         ` Mathieu Desnoyers
2010-09-23  3:49 ` [PATCH 04/11] jump label: Initialize workqueue tracepoints *before* they are registered Steven Rostedt
2010-09-23  3:49 ` [PATCH 05/11] jump label: Add jump_label_text_reserved() to reserve jump points Steven Rostedt
2010-09-23  3:49 ` Steven Rostedt [this message]
2010-09-23  3:49 ` [PATCH 07/11] jump label: Convert dynamic debug to use jump labels Steven Rostedt
2010-09-23  3:49 ` [PATCH 08/11] jump label: x86 support Steven Rostedt
2010-09-23  3:49 ` [PATCH 09/11] jump label: Add sparc64 support Steven Rostedt
2010-09-23  3:49 ` [PATCH 10/11] jump label: Remove duplicate structure for x86 Steven Rostedt
2010-09-23  3:49 ` [PATCH 11/11] jump label/x86/sparc64: Remove !CC_OPTIMIZE_FOR_SIZE config conditions Steven Rostedt
2010-09-23  4:06 ` [GIT PULL] jump label: add jump label code Steven Rostedt
2010-09-23  6:32   ` Ingo Molnar
2010-09-23 12:42 ` Steven Rostedt
2010-09-24  9:02 ` [tip:perf/core] jump label: Fix GCC feature check when distcc is used tip-bot for Ingo Molnar

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