tracing: Consolidate max_tr into main trace_array structure

Currently, the way the latency tracers and snapshot feature works
is to have a separate trace_array called "max_tr" that holds the
snapshot buffer. For latency tracers, this snapshot buffer is used
to swap the running buffer with this buffer to save the current max
latency.

The only items needed for the max_tr is really just a copy of the buffer
itself, the per_cpu data pointers, the time_start timestamp that states
when the max latency was triggered, and the cpu that the max latency
was triggered on. All other fields in trace_array are unused by the
max_tr, making the max_tr mostly bloat.

This change removes the max_tr completely, and adds a new structure
called trace_buffer, that holds the buffer pointer, the per_cpu data
pointers, the time_start timestamp, and the cpu where the latency occurred.

The trace_array, now has two trace_buffers, one for the normal trace and
one for the max trace or snapshot. By doing this, not only do we remove
the bloat from the max_trace but the instances of traces can now use
their own snapshot feature and not have just the top level global_trace have
the snapshot feature and latency tracers for itself.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/linux/ftrace_event.h

@@ -8,6 +8,7 @@
 #include <linux/perf_event.h>
 
 struct trace_array;
+struct trace_buffer;
 struct tracer;
 struct dentry;
 
@@ -67,6 +68,7 @@ struct trace_entry {
 struct trace_iterator {
 	struct trace_array	*tr;
 	struct tracer		*trace;
+	struct trace_buffer	*trace_buffer;
 	void			*private;
 	int			cpu_file;
 	struct mutex		mutex;

kernel/trace/blktrace.c

@@ -72,7 +72,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
 	bool blk_tracer = blk_tracer_enabled;
 
 	if (blk_tracer) {
-		buffer = blk_tr->buffer;
+		buffer = blk_tr->trace_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + len,
@@ -218,7 +218,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 	if (blk_tracer) {
 		tracing_record_cmdline(current);
 
-		buffer = blk_tr->buffer;
+		buffer = blk_tr->trace_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + pdu_len,

kernel/trace/trace.h

@@ -167,16 +167,37 @@ struct trace_array_cpu {
 
 struct tracer;
 
+struct trace_buffer {
+	struct trace_array		*tr;
+	struct ring_buffer		*buffer;
+	struct trace_array_cpu __percpu	*data;
+	cycle_t				time_start;
+	int				cpu;
+};
+
 /*
  * The trace array - an array of per-CPU trace arrays. This is the
  * highest level data structure that individual tracers deal with.
  * They have on/off state as well:
  */
 struct trace_array {
-	struct ring_buffer	*buffer;
 	struct list_head	list;
 	char			*name;
-	int			cpu;
+	struct trace_buffer	trace_buffer;
+#ifdef CONFIG_TRACER_MAX_TRACE
+	/*
+	 * The max_buffer is used to snapshot the trace when a maximum
+	 * latency is reached, or when the user initiates a snapshot.
+	 * Some tracers will use this to store a maximum trace while
+	 * it continues examining live traces.
+	 *
+	 * The buffers for the max_buffer are set up the same as the trace_buffer
+	 * When a snapshot is taken, the buffer of the max_buffer is swapped
+	 * with the buffer of the trace_buffer and the buffers are reset for
+	 * the trace_buffer so the tracing can continue.
+	 */
+	struct trace_buffer	max_buffer;
+#endif
 	int			buffer_disabled;
 	struct trace_cpu	trace_cpu;	/* place holder */
 #ifdef CONFIG_FTRACE_SYSCALLS
@@ -189,7 +210,6 @@ struct trace_array {
 	int			clock_id;
 	struct tracer		*current_trace;
 	unsigned int		flags;
-	cycle_t			time_start;
 	raw_spinlock_t		start_lock;
 	struct dentry		*dir;
 	struct dentry		*options;
@@ -198,7 +218,6 @@ struct trace_array {
 	struct list_head	systems;
 	struct list_head	events;
 	struct task_struct	*waiter;
-	struct trace_array_cpu __percpu	*data;
 };
 
 enum {
@@ -345,9 +364,11 @@ struct tracer {
 	struct tracer		*next;
 	struct tracer_flags	*flags;
 	bool			print_max;
+	bool			enabled;
+#ifdef CONFIG_TRACER_MAX_TRACE
 	bool			use_max_tr;
 	bool			allocated_snapshot;
-	bool			enabled;
+#endif
 };
 
 
@@ -493,8 +514,8 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
-void tracing_reset(struct trace_array *tr, int cpu);
-void tracing_reset_online_cpus(struct trace_array *tr);
+void tracing_reset(struct trace_buffer *buf, int cpu);
+void tracing_reset_online_cpus(struct trace_buffer *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
@@ -674,6 +695,8 @@ trace_array_vprintk(struct trace_array *tr,
 		    unsigned long ip, const char *fmt, va_list args);
 int trace_array_printk(struct trace_array *tr,
 		       unsigned long ip, const char *fmt, ...);
+int trace_array_printk_buf(struct ring_buffer *buffer,
+			   unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);
 

kernel/trace/trace_functions.c

@@ -28,7 +28,7 @@ static void tracing_stop_function_trace(void);
 static int function_trace_init(struct trace_array *tr)
 {
 	func_trace = tr;
-	tr->cpu = get_cpu();
+	tr->trace_buffer.cpu = get_cpu();
 	put_cpu();
 
 	tracing_start_cmdline_record();
@@ -44,7 +44,7 @@ static void function_trace_reset(struct trace_array *tr)
 
 static void function_trace_start(struct trace_array *tr)
 {
-	tracing_reset_online_cpus(tr);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 }
 
 /* Our option */
@@ -76,7 +76,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
 		goto out;
 
 	cpu = smp_processor_id();
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	if (!atomic_read(&data->disabled)) {
 		local_save_flags(flags);
 		trace_function(tr, ip, parent_ip, flags, pc);
@@ -107,7 +107,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
 	 */
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1)) {

kernel/trace/trace_functions_graph.c

@@ -218,7 +218,7 @@ int __trace_graph_entry(struct trace_array *tr,
 {
 	struct ftrace_event_call *call = &event_funcgraph_entry;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ent_entry *entry;
 
 	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
@@ -265,7 +265,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -323,7 +323,7 @@ void __trace_graph_return(struct trace_array *tr,
 {
 	struct ftrace_event_call *call = &event_funcgraph_exit;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ret_entry *entry;
 
 	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
@@ -350,7 +350,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -560,9 +560,9 @@ get_return_for_leaf(struct trace_iterator *iter,
 			 * We need to consume the current entry to see
 			 * the next one.
 			 */
-			ring_buffer_consume(iter->tr->buffer, iter->cpu,
+			ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
 					    NULL, NULL);
-			event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+			event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
 						 NULL, NULL);
 		}
 

kernel/trace/trace_irqsoff.c

@@ -121,7 +121,7 @@ static int func_prolog_dec(struct trace_array *tr,
 	if (!irqs_disabled_flags(*flags))
 		return 0;
 
-	*data = per_cpu_ptr(tr->data, cpu);
+	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 
 	if (likely(disabled == 1))
@@ -175,7 +175,7 @@ static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
 		per_cpu(tracing_cpu, cpu) = 0;
 
 	tracing_max_latency = 0;
-	tracing_reset_online_cpus(irqsoff_trace);
+	tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
 
 	return start_irqsoff_tracer(irqsoff_trace, set);
 }
@@ -380,7 +380,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
 	if (per_cpu(tracing_cpu, cpu))
 		return;
 
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 
 	if (unlikely(!data) || atomic_read(&data->disabled))
 		return;
@@ -418,7 +418,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 	if (!tracer_enabled)
 		return;
 
-	data = per_cpu_ptr(tr->data, cpu);
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 
 	if (unlikely(!data) ||
 	    !data->critical_start || atomic_read(&data->disabled))
@@ -568,7 +568,7 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();
-	tracing_reset_online_cpus(tr);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 
 	if (start_irqsoff_tracer(tr, is_graph()))
 		printk(KERN_ERR "failed to start irqsoff tracer\n");

kernel/trace/trace_kdb.c

@@ -26,7 +26,7 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file)
 	trace_init_global_iter(&iter);
 
 	for_each_tracing_cpu(cpu) {
-		atomic_inc(&per_cpu_ptr(iter.tr->data, cpu)->disabled);
+		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
 	}
 
 	old_userobj = trace_flags;
@@ -46,14 +46,14 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file)
 	if (cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter.buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter.tr->buffer, cpu);
+			ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu);
 			ring_buffer_read_start(iter.buffer_iter[cpu]);
 			tracing_iter_reset(&iter, cpu);
 		}
 	} else {
 		iter.cpu_file = cpu_file;
 		iter.buffer_iter[cpu_file] =
-			ring_buffer_read_prepare(iter.tr->buffer, cpu_file);
+			ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file);
 		ring_buffer_read_start(iter.buffer_iter[cpu_file]);
 		tracing_iter_reset(&iter, cpu_file);
 	}
@@ -83,7 +83,7 @@ out:
 	trace_flags = old_userobj;
 
 	for_each_tracing_cpu(cpu) {
-		atomic_dec(&per_cpu_ptr(iter.tr->data, cpu)->disabled);
+		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
 	}
 
 	for_each_tracing_cpu(cpu)

kernel/trace/trace_mmiotrace.c

@@ -31,7 +31,7 @@ static void mmio_reset_data(struct trace_array *tr)
 	overrun_detected = false;
 	prev_overruns = 0;
 
-	tracing_reset_online_cpus(tr);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 }
 
 static int mmio_trace_init(struct trace_array *tr)
@@ -128,7 +128,7 @@ static void mmio_close(struct trace_iterator *iter)
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
 	unsigned long cnt = atomic_xchg(&dropped_count, 0);
-	unsigned long over = ring_buffer_overruns(iter->tr->buffer);
+	unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer);
 
 	if (over > prev_overruns)
 		cnt += over - prev_overruns;
@@ -309,7 +309,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 				struct mmiotrace_rw *rw)
 {
 	struct ftrace_event_call *call = &event_mmiotrace_rw;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_rw *entry;
 	int pc = preempt_count();
@@ -330,7 +330,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 void mmio_trace_rw(struct mmiotrace_rw *rw)
 {
 	struct trace_array *tr = mmio_trace_array;
-	struct trace_array_cpu *data = per_cpu_ptr(tr->data, smp_processor_id());
+	struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
 	__trace_mmiotrace_rw(tr, data, rw);
 }
 
@@ -339,7 +339,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
 				struct mmiotrace_map *map)
 {
 	struct ftrace_event_call *call = &event_mmiotrace_map;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_map *entry;
 	int pc = preempt_count();
@@ -363,7 +363,7 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
 	struct trace_array_cpu *data;
 
 	preempt_disable();
-	data = per_cpu_ptr(tr->data, smp_processor_id());
+	data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
 	__trace_mmiotrace_map(tr, data, map);
 	preempt_enable();
 }

kernel/trace/trace_output.c

@@ -643,7 +643,7 @@ lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 {
 	unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
-	unsigned long long abs_ts = iter->ts - iter->tr->time_start;
+	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 	unsigned long long rel_ts = next_ts - iter->ts;
 	struct trace_seq *s = &iter->seq;
 

kernel/trace/trace_sched_switch.c

@@ -28,7 +28,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
 			   unsigned long flags, int pc)
 {
 	struct ftrace_event_call *call = &event_context_switch;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
 
@@ -69,7 +69,7 @@ probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *n
 	pc = preempt_count();
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(ctx_trace->data, cpu);
+	data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu);
 
 	if (likely(!atomic_read(&data->disabled)))
 		tracing_sched_switch_trace(ctx_trace, prev, next, flags, pc);
@@ -86,7 +86,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 	struct ftrace_event_call *call = &event_wakeup;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
-	struct ring_buffer *buffer = tr->buffer;
+	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
 					  sizeof(*entry), flags, pc);
@@ -123,7 +123,7 @@ probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success)
 	pc = preempt_count();
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(ctx_trace->data, cpu);
+	data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu);
 
 	if (likely(!atomic_read(&data->disabled)))
 		tracing_sched_wakeup_trace(ctx_trace, wakee, current,

kernel/trace/trace_sched_wakeup.c

@@ -89,7 +89,7 @@ func_prolog_preempt_disable(struct trace_array *tr,
 	if (cpu != wakeup_current_cpu)
 		goto out_enable;
 
-	*data = per_cpu_ptr(tr->data, cpu);
+	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
@@ -353,7 +353,7 @@ probe_wakeup_sched_switch(void *ignore,
 
 	/* disable local data, not wakeup_cpu data */
 	cpu = raw_smp_processor_id();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 	if (likely(disabled != 1))
 		goto out;
 
@@ -365,7 +365,7 @@ probe_wakeup_sched_switch(void *ignore,
 		goto out_unlock;
 
 	/* The task we are waiting for is waking up */
-	data = per_cpu_ptr(wakeup_trace->data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
 
 	__trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc);
 	tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc);
@@ -387,7 +387,7 @@ out_unlock:
 	arch_spin_unlock(&wakeup_lock);
 	local_irq_restore(flags);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 }
 
 static void __wakeup_reset(struct trace_array *tr)
@@ -405,7 +405,7 @@ static void wakeup_reset(struct trace_array *tr)
 {
 	unsigned long flags;
 
-	tracing_reset_online_cpus(tr);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 
 	local_irq_save(flags);
 	arch_spin_lock(&wakeup_lock);
@@ -435,7 +435,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
 		return;
 
 	pc = preempt_count();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
 
@@ -458,7 +458,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
 
 	local_save_flags(flags);
 
-	data = per_cpu_ptr(wakeup_trace->data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
 	data->preempt_timestamp = ftrace_now(cpu);
 	tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc);
 
@@ -472,7 +472,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
 out_locked:
 	arch_spin_unlock(&wakeup_lock);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 }
 
 static void start_wakeup_tracer(struct trace_array *tr)

kernel/trace/trace_selftest.c

@@ -21,13 +21,13 @@ static inline int trace_valid_entry(struct trace_entry *entry)
 	return 0;
 }
 
-static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
+static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
 {
 	struct ring_buffer_event *event;
 	struct trace_entry *entry;
 	unsigned int loops = 0;
 
-	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL, NULL))) {
+	while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) {
 		entry = ring_buffer_event_data(event);
 
 		/*
@@ -58,7 +58,7 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
  * Test the trace buffer to see if all the elements
  * are still sane.
  */
-static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
+static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
 {
 	unsigned long flags, cnt = 0;
 	int cpu, ret = 0;
@@ -67,7 +67,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	local_irq_save(flags);
 	arch_spin_lock(&ftrace_max_lock);
 
-	cnt = ring_buffer_entries(tr->buffer);
+	cnt = ring_buffer_entries(buf->buffer);
 
 	/*
 	 * The trace_test_buffer_cpu runs a while loop to consume all data.
@@ -78,7 +78,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	 */
 	tracing_off();
 	for_each_possible_cpu(cpu) {
-		ret = trace_test_buffer_cpu(tr, cpu);
+		ret = trace_test_buffer_cpu(buf, cpu);
 		if (ret)
 			break;
 	}
@@ -355,7 +355,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	msleep(100);
 
 	/* we should have nothing in the buffer */
-	ret = trace_test_buffer(tr, &count);
+	ret = trace_test_buffer(&tr->trace_buffer, &count);
 	if (ret)
 		goto out;
 
@@ -376,7 +376,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(tr, &count);
+	ret = trace_test_buffer(&tr->trace_buffer, &count);
 	tracing_start();
 
 	/* we should only have one item */
@@ -666,7 +666,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(tr, &count);
+	ret = trace_test_buffer(&tr->trace_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
@@ -737,7 +737,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	 * Simulate the init() callback but we attach a watchdog callback
 	 * to detect and recover from possible hangs
 	 */
-	tracing_reset_online_cpus(tr);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 	set_graph_array(tr);
 	ret = register_ftrace_graph(&trace_graph_return,
 				    &trace_graph_entry_watchdog);
@@ -760,7 +760,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	tracing_stop();
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(tr, &count);
+	ret = trace_test_buffer(&tr->trace_buffer, &count);
 
 	trace->reset(tr);
 	tracing_start();
@@ -815,9 +815,9 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(tr, NULL);
+	ret = trace_test_buffer(&tr->trace_buffer, NULL);
 	if (!ret)
-		ret = trace_test_buffer(&max_tr, &count);
+		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
@@ -877,9 +877,9 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(tr, NULL);
+	ret = trace_test_buffer(&tr->trace_buffer, NULL);
 	if (!ret)
-		ret = trace_test_buffer(&max_tr, &count);
+		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
@@ -943,11 +943,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(tr, NULL);
+	ret = trace_test_buffer(&tr->trace_buffer, NULL);
 	if (ret)
 		goto out;
 
-	ret = trace_test_buffer(&max_tr, &count);
+	ret = trace_test_buffer(&tr->max_buffer, &count);
 	if (ret)
 		goto out;
 
@@ -973,11 +973,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(tr, NULL);
+	ret = trace_test_buffer(&tr->trace_buffer, NULL);
 	if (ret)
 		goto out;
 
-	ret = trace_test_buffer(&max_tr, &count);
+	ret = trace_test_buffer(&tr->max_buffer, &count);
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -1084,10 +1084,10 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(tr, NULL);
+	ret = trace_test_buffer(&tr->trace_buffer, NULL);
 	printk("ret = %d\n", ret);
 	if (!ret)
-		ret = trace_test_buffer(&max_tr, &count);
+		ret = trace_test_buffer(&tr->max_buffer, &count);
 
 
 	trace->reset(tr);
@@ -1126,7 +1126,7 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
 	/* stop the tracing. */
 	tracing_stop();
 	/* check the trace buffer */
-	ret = trace_test_buffer(tr, &count);
+	ret = trace_test_buffer(&tr->trace_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 

kernel/trace/trace_syscalls.c

@@ -321,7 +321,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 
 	size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
 
-	buffer = tr->buffer;
+	buffer = tr->trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->enter_event->event.type, size, 0, 0);
 	if (!event)
@@ -355,7 +355,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	if (!sys_data)
 		return;
 
-	buffer = tr->buffer;
+	buffer = tr->trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->exit_event->event.type, sizeof(*entry), 0, 0);
 	if (!event)