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Commit 8f7b50c5 authored by Jason Baron's avatar Jason Baron Committed by Steven Rostedt
Browse files

jump label: Tracepoint support for jump labels 



Make use of the jump label infrastructure for tracepoints.

Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 4c3ef6d7

include/linux/tracepoint.h

+4 −1
Original line number Diff line number Diff line
@@ -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));			\

kernel/tracepoint.c

+12 −2
Original line number Diff line number Diff line
@@ -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);

	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();



	if (elem->state) {

		disable_jump_label(&elem->state);

		elem->state = 0;

	}

	rcu_assign_pointer(elem->funcs, NULL);

}