Commit ae63b31e authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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tracing: Separate out trace events from global variables 



The trace events for ftrace are all defined via global variables.
The arrays of events and event systems are linked to a global list.
This prevents multiple users of the event system (what to enable and
what not to).

By adding descriptors to represent the event/file relation, as well
as to which trace_array descriptor they are associated with, allows
for more than one set of events to be defined. Once the trace events
files have a link between the trace event and the trace_array they
are associated with, we can create multiple trace_arrays that can
record separate events in separate buffers.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 613f04a0

include/linux/ftrace_event.h

+40 −11
Original line number Diff line number Diff line
@@ -182,18 +182,20 @@ extern int ftrace_event_reg(struct ftrace_event_call *event, 
			    enum trace_reg type, void *data);



enum {

	TRACE_EVENT_FL_ENABLED_BIT,

	TRACE_EVENT_FL_FILTERED_BIT,

	TRACE_EVENT_FL_RECORDED_CMD_BIT,

	TRACE_EVENT_FL_CAP_ANY_BIT,

	TRACE_EVENT_FL_NO_SET_FILTER_BIT,

	TRACE_EVENT_FL_IGNORE_ENABLE_BIT,

};



/*

 * Event flags:

 *  FILTERED	  - The event has a filter attached

 *  CAP_ANY	  - Any user can enable for perf

 *  NO_SET_FILTER - Set when filter has error and is to be ignored

 */

enum {

	TRACE_EVENT_FL_ENABLED		= (1 << TRACE_EVENT_FL_ENABLED_BIT),

	TRACE_EVENT_FL_FILTERED		= (1 << TRACE_EVENT_FL_FILTERED_BIT),

	TRACE_EVENT_FL_RECORDED_CMD	= (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),

	TRACE_EVENT_FL_CAP_ANY		= (1 << TRACE_EVENT_FL_CAP_ANY_BIT),

	TRACE_EVENT_FL_NO_SET_FILTER	= (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),

	TRACE_EVENT_FL_IGNORE_ENABLE	= (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
@@ -203,12 +205,44 @@ struct ftrace_event_call { 
	struct list_head	list;

	struct ftrace_event_class *class;

	char			*name;

	struct dentry		*dir;

	struct trace_event	event;

	const char		*print_fmt;

	struct event_filter	*filter;

	struct list_head	*files;

	void			*mod;

	void			*data;

	int			flags; /* static flags of different events */



#ifdef CONFIG_PERF_EVENTS

	int				perf_refcount;

	struct hlist_head __percpu	*perf_events;

#endif

};



struct trace_array;

struct ftrace_subsystem_dir;



enum {

	FTRACE_EVENT_FL_ENABLED_BIT,

	FTRACE_EVENT_FL_RECORDED_CMD_BIT,

};



/*

 * Ftrace event file flags:

 *  ENABELD	  - The event is enabled

 *  RECORDED_CMD  - The comms should be recorded at sched_switch

 */

enum {

	FTRACE_EVENT_FL_ENABLED		= (1 << FTRACE_EVENT_FL_ENABLED_BIT),

	FTRACE_EVENT_FL_RECORDED_CMD	= (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),

};



struct ftrace_event_file {

	struct list_head		list;

	struct ftrace_event_call	*event_call;

	struct dentry			*dir;

	struct trace_array		*tr;

	struct ftrace_subsystem_dir	*system;



	/*

	 * 32 bit flags:
@@ -223,17 +257,12 @@ struct ftrace_event_call { 
	 *

	 * Note: Reads of flags do not hold the event_mutex since

	 * they occur in critical sections. But the way flags

	 * is currently used, these changes do no affect the code

	 * is currently used, these changes do not affect the code

	 * except that when a change is made, it may have a slight

	 * delay in propagating the changes to other CPUs due to

	 * caching and such.

	 */

	unsigned int		flags;



#ifdef CONFIG_PERF_EVENTS

	int				perf_refcount;

	struct hlist_head __percpu	*perf_events;

#endif

};



#define __TRACE_EVENT_FLAGS(name, value)				\

include/trace/ftrace.h

+2 −1
Original line number Diff line number Diff line
@@ -518,7 +518,8 @@ static inline notrace int ftrace_get_offsets_##call( \ 
static notrace void							\

ftrace_raw_event_##call(void *__data, proto)				\

{									\

	struct ftrace_event_call *event_call = __data;			\

	struct ftrace_event_file *ftrace_file = __data;			\

	struct ftrace_event_call *event_call = ftrace_file->event_call;	\

	struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\

	struct ring_buffer_event *event;				\

	struct ftrace_raw_##call *entry;				\

kernel/trace/trace.c

+8 −0
Original line number Diff line number Diff line
@@ -189,6 +189,8 @@ unsigned long long ns2usecs(cycle_t nsec) 
 */

static struct trace_array	global_trace;



LIST_HEAD(ftrace_trace_arrays);



static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);



int filter_current_check_discard(struct ring_buffer *buffer,
@@ -5359,6 +5361,12 @@ __init static int tracer_alloc_buffers(void) 


	register_die_notifier(&trace_die_notifier);



	global_trace.flags = TRACE_ARRAY_FL_GLOBAL;



	INIT_LIST_HEAD(&global_trace.systems);

	INIT_LIST_HEAD(&global_trace.events);

	list_add(&global_trace.list, &ftrace_trace_arrays);



	while (trace_boot_options) {

		char *option;

kernel/trace/trace.h

+36 −3
Original line number Diff line number Diff line
@@ -158,13 +158,39 @@ struct trace_array_cpu { 
 */

struct trace_array {

	struct ring_buffer	*buffer;

	struct list_head	list;

	int			cpu;

	int			buffer_disabled;

	unsigned int		flags;

	cycle_t			time_start;

	struct dentry		*dir;

	struct dentry		*event_dir;

	struct list_head	systems;

	struct list_head	events;

	struct task_struct	*waiter;

	struct trace_array_cpu	*data[NR_CPUS];

};



enum {

	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)

};



extern struct list_head ftrace_trace_arrays;



/*

 * The global tracer (top) should be the first trace array added,

 * but we check the flag anyway.

 */

static inline struct trace_array *top_trace_array(void)

{

	struct trace_array *tr;



	tr = list_entry(ftrace_trace_arrays.prev,

			typeof(*tr), list);

	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));

	return tr;

}



#define FTRACE_CMP_TYPE(var, type) \

	__builtin_types_compatible_p(typeof(var), type *)
@@ -851,12 +877,19 @@ struct event_filter { 
struct event_subsystem {

	struct list_head	list;

	const char		*name;

	struct dentry		*entry;

	struct event_filter	*filter;

	int			nr_events;

	int			ref_count;

};



struct ftrace_subsystem_dir {

	struct list_head		list;

	struct event_subsystem		*subsystem;

	struct trace_array		*tr;

	struct dentry			*entry;

	int				ref_count;

	int				nr_events;

};



#define FILTER_PRED_INVALID	((unsigned short)-1)

#define FILTER_PRED_IS_RIGHT	(1 << 15)

#define FILTER_PRED_FOLD	(1 << 15)
@@ -914,7 +947,7 @@ extern void print_event_filter(struct ftrace_event_call *call, 
			       struct trace_seq *s);

extern int apply_event_filter(struct ftrace_event_call *call,

			      char *filter_string);

extern int apply_subsystem_event_filter(struct event_subsystem *system,

extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,

					char *filter_string);

extern void print_subsystem_event_filter(struct event_subsystem *system,

					 struct trace_seq *s);

kernel/trace/trace_events.c

+533 −243

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