X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace_functions_graph.c;h=a43d009c561a28bcbf1078626e086c63bf475d5e;hb=be1eca39319689aed7d3aedb9c3bece9469fe10f;hp=c009553a8e815829cc47658744868d86d66e2d32;hpb=00a8bf859331e349713274825e6fbf20bf2ac15a;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index c009553..a43d009 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -14,6 +14,22 @@
 #include "trace.h"
 #include "trace_output.h"
 
+struct fgraph_cpu_data {
+	pid_t		last_pid;
+	int		depth;
+	int		ignore;
+};
+
+struct fgraph_data {
+	struct fgraph_cpu_data		*cpu_data;
+
+	/* Place to preserve last processed entry. */
+	struct ftrace_graph_ent_entry	ent;
+	struct ftrace_graph_ret_entry	ret;
+	int				failed;
+	int				cpu;
+};
+
 #define TRACE_GRAPH_INDENT	2
 
 /* Flag options */
@@ -47,38 +63,50 @@ static struct tracer_flags tracer_flags = {
 	.opts = trace_opts
 };
 
-/* pid on the last trace processed */
+static struct trace_array *graph_array;
 
 
 /* Add a function return address to the trace stack on thread info.*/
 int
-ftrace_push_return_trace(unsigned long ret, unsigned long long time,
-			 unsigned long func, int *depth)
+ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+			 unsigned long frame_pointer)
 {
+	unsigned long long calltime;
 	int index;
 
 	if (!current->ret_stack)
 		return -EBUSY;
 
+	/*
+	 * We must make sure the ret_stack is tested before we read
+	 * anything else.
+	 */
+	smp_rmb();
+
 	/* The return trace stack is full */
 	if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
 		atomic_inc(&current->trace_overrun);
 		return -EBUSY;
 	}
 
+	calltime = trace_clock_local();
+
 	index = ++current->curr_ret_stack;
 	barrier();
 	current->ret_stack[index].ret = ret;
 	current->ret_stack[index].func = func;
-	current->ret_stack[index].calltime = time;
+	current->ret_stack[index].calltime = calltime;
+	current->ret_stack[index].subtime = 0;
+	current->ret_stack[index].fp = frame_pointer;
 	*depth = index;
 
 	return 0;
 }
 
 /* Retrieve a function return address to the trace stack on thread info.*/
-void
-ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
+static void
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
+			unsigned long frame_pointer)
 {
 	int index;
 
@@ -92,28 +120,52 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
 		return;
 	}
 
+#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+	/*
+	 * The arch may choose to record the frame pointer used
+	 * and check it here to make sure that it is what we expect it
+	 * to be. If gcc does not set the place holder of the return
+	 * address in the frame pointer, and does a copy instead, then
+	 * the function graph trace will fail. This test detects this
+	 * case.
+	 *
+	 * Currently, x86_32 with optimize for size (-Os) makes the latest
+	 * gcc do the above.
+	 */
+	if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
+		ftrace_graph_stop();
+		WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
+		     "  from func %ps return to %lx\n",
+		     current->ret_stack[index].fp,
+		     frame_pointer,
+		     (void *)current->ret_stack[index].func,
+		     current->ret_stack[index].ret);
+		*ret = (unsigned long)panic;
+		return;
+	}
+#endif
+
 	*ret = current->ret_stack[index].ret;
 	trace->func = current->ret_stack[index].func;
 	trace->calltime = current->ret_stack[index].calltime;
 	trace->overrun = atomic_read(&current->trace_overrun);
 	trace->depth = index;
-	barrier();
-	current->curr_ret_stack--;
-
 }
 
 /*
  * Send the trace to the ring-buffer.
  * @return the original return address.
  */
-unsigned long ftrace_return_to_handler(void)
+unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 {
 	struct ftrace_graph_ret trace;
 	unsigned long ret;
 
-	ftrace_pop_return_trace(&trace, &ret);
-	trace.rettime = cpu_clock(raw_smp_processor_id());
+	ftrace_pop_return_trace(&trace, &ret, frame_pointer);
+	trace.rettime = trace_clock_local();
 	ftrace_graph_return(&trace);
+	barrier();
+	current->curr_ret_stack--;
 
 	if (unlikely(!ret)) {
 		ftrace_graph_stop();
@@ -125,10 +177,123 @@ unsigned long ftrace_return_to_handler(void)
 	return ret;
 }
 
+static int __trace_graph_entry(struct trace_array *tr,
+				struct ftrace_graph_ent *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ftrace_event_call *call = &event_funcgraph_entry;
+	struct ring_buffer_event *event;
+	struct ring_buffer *buffer = tr->buffer;
+	struct ftrace_graph_ent_entry *entry;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return 0;
+
+	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return 0;
+	entry	= ring_buffer_event_data(event);
+	entry->graph_ent			= *trace;
+	if (!filter_current_check_discard(buffer, call, entry, event))
+		ring_buffer_unlock_commit(buffer, event);
+
+	return 1;
+}
+
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+	struct trace_array *tr = graph_array;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int ret;
+	int cpu;
+	int pc;
+
+	if (unlikely(!tr))
+		return 0;
+
+	if (!ftrace_trace_task(current))
+		return 0;
+
+	if (!ftrace_graph_addr(trace->func))
+		return 0;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		ret = __trace_graph_entry(tr, trace, flags, pc);
+	} else {
+		ret = 0;
+	}
+	/* Only do the atomic if it is not already set */
+	if (!test_tsk_trace_graph(current))
+		set_tsk_trace_graph(current);
+
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+				struct ftrace_graph_ret *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ftrace_event_call *call = &event_funcgraph_exit;
+	struct ring_buffer_event *event;
+	struct ring_buffer *buffer = tr->buffer;
+	struct ftrace_graph_ret_entry *entry;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return;
+
+	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	entry->ret				= *trace;
+	if (!filter_current_check_discard(buffer, call, entry, event))
+		ring_buffer_unlock_commit(buffer, event);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+	struct trace_array *tr = graph_array;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		__trace_graph_return(tr, trace, flags, pc);
+	}
+	if (!trace->depth)
+		clear_tsk_trace_graph(current);
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+
 static int graph_trace_init(struct trace_array *tr)
 {
-	int ret = register_ftrace_graph(&trace_graph_return,
-					&trace_graph_entry);
+	int ret;
+
+	graph_array = tr;
+	ret = register_ftrace_graph(&trace_graph_return,
+				    &trace_graph_entry);
 	if (ret)
 		return ret;
 	tracing_start_cmdline_record();
@@ -136,49 +301,30 @@ static int graph_trace_init(struct trace_array *tr)
 	return 0;
 }
 
+void set_graph_array(struct trace_array *tr)
+{
+	graph_array = tr;
+}
+
 static void graph_trace_reset(struct trace_array *tr)
 {
 	tracing_stop_cmdline_record();
 	unregister_ftrace_graph();
 }
 
-static inline int log10_cpu(int nb)
-{
-	if (nb / 100)
-		return 3;
-	if (nb / 10)
-		return 2;
-	return 1;
-}
+static int max_bytes_for_cpu;
 
 static enum print_line_t
 print_graph_cpu(struct trace_seq *s, int cpu)
 {
-	int i;
 	int ret;
-	int log10_this = log10_cpu(cpu);
-	int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
-
 
 	/*
 	 * Start with a space character - to make it stand out
 	 * to the right a bit when trace output is pasted into
 	 * email:
 	 */
-	ret = trace_seq_printf(s, " ");
-
-	/*
-	 * Tricky - we space the CPU field according to the max
-	 * number of online CPUs. On a 2-cpu system it would take
-	 * a maximum of 1 digit - on a 128 cpu system it would
-	 * take up to 3 digits:
-	 */
-	for (i = 0; i < log10_all - log10_this; i++) {
-		ret = trace_seq_printf(s, " ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-	ret = trace_seq_printf(s, "%d) ", cpu);
+	ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -190,15 +336,15 @@ print_graph_cpu(struct trace_seq *s, int cpu)
 static enum print_line_t
 print_graph_proc(struct trace_seq *s, pid_t pid)
 {
-	int i;
-	int ret;
-	int len;
-	char comm[8];
-	int spaces = 0;
+	char comm[TASK_COMM_LEN];
 	/* sign + log10(MAX_INT) + '\0' */
 	char pid_str[11];
+	int spaces = 0;
+	int ret;
+	int len;
+	int i;
 
-	strncpy(comm, trace_find_cmdline(pid), 7);
+	trace_find_cmdline(pid, comm);
 	comm[7] = '\0';
 	sprintf(pid_str, "%d", pid);
 
@@ -229,18 +375,27 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
 }
 
 
+static enum print_line_t
+print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
+{
+	if (!trace_seq_putc(s, ' '))
+		return 0;
+
+	return trace_print_lat_fmt(s, entry);
+}
+
 /* If the pid changed since the last trace, output this event */
 static enum print_line_t
-verif_pid(struct trace_seq *s, pid_t pid, int cpu, pid_t *last_pids_cpu)
+verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
 {
 	pid_t prev_pid;
 	pid_t *last_pid;
 	int ret;
 
-	if (!last_pids_cpu)
+	if (!data)
 		return TRACE_TYPE_HANDLED;
 
-	last_pid = per_cpu_ptr(last_pids_cpu, cpu);
+	last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
 
 	if (*last_pid == pid)
 		return TRACE_TYPE_HANDLED;
@@ -291,26 +446,49 @@ static struct ftrace_graph_ret_entry *
 get_return_for_leaf(struct trace_iterator *iter,
 		struct ftrace_graph_ent_entry *curr)
 {
-	struct ring_buffer_iter *ring_iter;
+	struct fgraph_data *data = iter->private;
+	struct ring_buffer_iter *ring_iter = NULL;
 	struct ring_buffer_event *event;
 	struct ftrace_graph_ret_entry *next;
 
-	ring_iter = iter->buffer_iter[iter->cpu];
+	/*
+	 * If the previous output failed to write to the seq buffer,
+	 * then we just reuse the data from before.
+	 */
+	if (data && data->failed) {
+		curr = &data->ent;
+		next = &data->ret;
+	} else {
+
+		ring_iter = iter->buffer_iter[iter->cpu];
+
+		/* First peek to compare current entry and the next one */
+		if (ring_iter)
+			event = ring_buffer_iter_peek(ring_iter, NULL);
+		else {
+			/*
+			 * We need to consume the current entry to see
+			 * the next one.
+			 */
+			ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+			event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+						 NULL);
+		}
 
-	/* First peek to compare current entry and the next one */
-	if (ring_iter)
-		event = ring_buffer_iter_peek(ring_iter, NULL);
-	else {
-	/* We need to consume the current entry to see the next one */
-		ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
-		event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
-					NULL);
-	}
+		if (!event)
+			return NULL;
 
-	if (!event)
-		return NULL;
+		next = ring_buffer_event_data(event);
 
-	next = ring_buffer_event_data(event);
+		if (data) {
+			/*
+			 * Save current and next entries for later reference
+			 * if the output fails.
+			 */
+			data->ent = *curr;
+			data->ret = *next;
+		}
+	}
 
 	if (next->ent.type != TRACE_GRAPH_RET)
 		return NULL;
@@ -386,6 +564,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		if (ret == TRACE_TYPE_PARTIAL_LINE)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
+
 	/* Proc */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
 		ret = print_graph_proc(s, pid);
@@ -419,8 +598,8 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 	return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t
-print_graph_duration(unsigned long long duration, struct trace_seq *s)
+enum print_line_t
+trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 {
 	unsigned long nsecs_rem = do_div(duration, 1000);
 	/* log10(ULONG_MAX) + '\0' */
@@ -457,12 +636,23 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s)
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_duration(unsigned long long duration, struct trace_seq *s)
+{
+	int ret;
+
+	ret = trace_print_graph_duration(duration, s);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
 
 	ret = trace_seq_printf(s, "|  ");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
-	return TRACE_TYPE_HANDLED;
 
+	return TRACE_TYPE_HANDLED;
 }
 
 /* Case of a leaf function on its call entry */
@@ -471,6 +661,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 		struct ftrace_graph_ent_entry *entry,
 		struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
 {
+	struct fgraph_data *data = iter->private;
 	struct ftrace_graph_ret *graph_ret;
 	struct ftrace_graph_ent *call;
 	unsigned long long duration;
@@ -481,6 +672,18 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 	call = &entry->graph_ent;
 	duration = graph_ret->rettime - graph_ret->calltime;
 
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+
+		/*
+		 * Comments display at + 1 to depth. Since
+		 * this is a leaf function, keep the comments
+		 * equal to this depth.
+		 */
+		*depth = call->depth - 1;
+	}
+
 	/* Overhead */
 	ret = print_graph_overhead(duration, s);
 	if (!ret)
@@ -500,11 +703,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = seq_print_ip_sym(s, call->func, 0);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_printf(s, "();\n");
+	ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -512,12 +711,21 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 }
 
 static enum print_line_t
-print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
-			struct trace_seq *s, pid_t pid, int cpu)
+print_graph_entry_nested(struct trace_iterator *iter,
+			 struct ftrace_graph_ent_entry *entry,
+			 struct trace_seq *s, int cpu)
 {
-	int i;
-	int ret;
 	struct ftrace_graph_ent *call = &entry->graph_ent;
+	struct fgraph_data *data = iter->private;
+	int ret;
+	int i;
+
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+
+		*depth = call->depth;
+	}
 
 	/* No overhead */
 	ret = print_graph_overhead(-1, s);
@@ -538,11 +746,7 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = seq_print_ip_sym(s, call->func, 0);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_printf(s, "() {\n");
+	ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -554,24 +758,24 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
 }
 
 static enum print_line_t
-print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
-			struct trace_iterator *iter)
+print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
+		     int type, unsigned long addr)
 {
-	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_entry = iter->private;
+	struct fgraph_data *data = iter->private;
 	struct trace_entry *ent = iter->ent;
-	struct ftrace_graph_ent *call = &field->graph_ent;
-	struct ftrace_graph_ret_entry *leaf_ret;
+	int cpu = iter->cpu;
+	int ret;
 
 	/* Pid */
-	if (verif_pid(s, ent->pid, cpu, last_entry) == TRACE_TYPE_PARTIAL_LINE)
+	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Interrupt */
-	ret = print_graph_irq(iter, call->func, TRACE_GRAPH_ENT, cpu, ent->pid);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	if (type) {
+		/* Interrupt */
+		ret = print_graph_irq(iter, addr, type, cpu, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
 
 	/* Absolute time */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
@@ -598,52 +802,75 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
+	/* Latency format */
+	if (trace_flags & TRACE_ITER_LATENCY_FMT) {
+		ret = print_graph_lat_fmt(s, ent);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	return 0;
+}
+
+static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
+			struct trace_iterator *iter)
+{
+	struct fgraph_data *data = iter->private;
+	struct ftrace_graph_ent *call = &field->graph_ent;
+	struct ftrace_graph_ret_entry *leaf_ret;
+	static enum print_line_t ret;
+	int cpu = iter->cpu;
+
+	if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func))
+		return TRACE_TYPE_PARTIAL_LINE;
+
 	leaf_ret = get_return_for_leaf(iter, field);
 	if (leaf_ret)
-		return print_graph_entry_leaf(iter, field, leaf_ret, s);
+		ret = print_graph_entry_leaf(iter, field, leaf_ret, s);
 	else
-		return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
+		ret = print_graph_entry_nested(iter, field, s, cpu);
+
+	if (data) {
+		/*
+		 * If we failed to write our output, then we need to make
+		 * note of it. Because we already consumed our entry.
+		 */
+		if (s->full) {
+			data->failed = 1;
+			data->cpu = cpu;
+		} else
+			data->failed = 0;
+	}
 
+	return ret;
 }
 
 static enum print_line_t
 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 		   struct trace_entry *ent, struct trace_iterator *iter)
 {
-	int i;
-	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_pid = iter->private, pid = ent->pid;
 	unsigned long long duration = trace->rettime - trace->calltime;
+	struct fgraph_data *data = iter->private;
+	pid_t pid = ent->pid;
+	int cpu = iter->cpu;
+	int ret;
+	int i;
 
-	/* Pid */
-	if (verif_pid(s, pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Absolute time */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
 
-	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
+		/*
+		 * Comments display at + 1 to depth. This is the
+		 * return from a function, we now want the comments
+		 * to display at the same level of the bracket.
+		 */
+		*depth = trace->depth - 1;
 	}
 
-	/* Proc */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
-		ret = print_graph_proc(s, ent->pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (print_graph_prologue(iter, s, 0, 0))
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Overhead */
 	ret = print_graph_overhead(duration, s);
@@ -684,42 +911,21 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 }
 
 static enum print_line_t
-print_graph_comment(struct print_entry *trace, struct trace_seq *s,
-		   struct trace_entry *ent, struct trace_iterator *iter)
+print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
+		    struct trace_iterator *iter)
 {
-	int i;
+	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
+	struct fgraph_data *data = iter->private;
+	struct trace_event *event;
+	int depth = 0;
 	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_pid = iter->private;
-
-	/* Pid */
-	if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Absolute time */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	int i;
 
-	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (data)
+		depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
 
-	/* Proc */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
-		ret = print_graph_proc(s, ent->pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (print_graph_prologue(iter, s, 0, 0))
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* No overhead */
 	ret = print_graph_overhead(-1, s);
@@ -734,18 +940,39 @@ print_graph_comment(struct print_entry *trace, struct trace_seq *s,
 	}
 
 	/* Indentation */
-	if (trace->depth > 0)
-		for (i = 0; i < (trace->depth + 1) * TRACE_GRAPH_INDENT; i++) {
+	if (depth > 0)
+		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
 			ret = trace_seq_printf(s, " ");
 			if (!ret)
 				return TRACE_TYPE_PARTIAL_LINE;
 		}
 
 	/* The comment */
-	ret = trace_seq_printf(s, "/* %s", trace->buf);
+	ret = trace_seq_printf(s, "/* ");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	switch (iter->ent->type) {
+	case TRACE_BPRINT:
+		ret = trace_print_bprintk_msg_only(iter);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+		break;
+	case TRACE_PRINT:
+		ret = trace_print_printk_msg_only(iter);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+		break;
+	default:
+		event = ftrace_find_event(ent->type);
+		if (!event)
+			return TRACE_TYPE_UNHANDLED;
+
+		ret = event->trace(iter, sym_flags);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+	}
+
 	/* Strip ending newline */
 	if (s->buffer[s->len - 1] == '\n') {
 		s->buffer[s->len - 1] = '\0';
@@ -763,52 +990,112 @@ print_graph_comment(struct print_entry *trace, struct trace_seq *s,
 enum print_line_t
 print_graph_function(struct trace_iterator *iter)
 {
-	struct trace_seq *s = &iter->seq;
+	struct ftrace_graph_ent_entry *field;
+	struct fgraph_data *data = iter->private;
 	struct trace_entry *entry = iter->ent;
+	struct trace_seq *s = &iter->seq;
+	int cpu = iter->cpu;
+	int ret;
+
+	if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
+		per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
+		return TRACE_TYPE_HANDLED;
+	}
+
+	/*
+	 * If the last output failed, there's a possibility we need
+	 * to print out the missing entry which would never go out.
+	 */
+	if (data && data->failed) {
+		field = &data->ent;
+		iter->cpu = data->cpu;
+		ret = print_graph_entry(field, s, iter);
+		if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
+			per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
+			ret = TRACE_TYPE_NO_CONSUME;
+		}
+		iter->cpu = cpu;
+		return ret;
+	}
 
 	switch (entry->type) {
 	case TRACE_GRAPH_ENT: {
-		struct ftrace_graph_ent_entry *field;
+		/*
+		 * print_graph_entry() may consume the current event,
+		 * thus @field may become invalid, so we need to save it.
+		 * sizeof(struct ftrace_graph_ent_entry) is very small,
+		 * it can be safely saved at the stack.
+		 */
+		struct ftrace_graph_ent_entry saved;
 		trace_assign_type(field, entry);
-		return print_graph_entry(field, s, iter);
+		saved = *field;
+		return print_graph_entry(&saved, s, iter);
 	}
 	case TRACE_GRAPH_RET: {
 		struct ftrace_graph_ret_entry *field;
 		trace_assign_type(field, entry);
 		return print_graph_return(&field->ret, s, entry, iter);
 	}
-	case TRACE_PRINT: {
-		struct print_entry *field;
-		trace_assign_type(field, entry);
-		return print_graph_comment(field, s, entry, iter);
-	}
 	default:
-		return TRACE_TYPE_UNHANDLED;
+		return print_graph_comment(s, entry, iter);
 	}
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static void print_lat_header(struct seq_file *s)
+{
+	static const char spaces[] = "                "	/* 16 spaces */
+		"    "					/* 4 spaces */
+		"                 ";			/* 17 spaces */
+	int size = 0;
+
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
+		size += 16;
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+		size += 4;
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+		size += 17;
+
+	seq_printf(s, "#%.*s  _-----=> irqs-off        \n", size, spaces);
+	seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
+	seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
+	seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
+	seq_printf(s, "#%.*s||| / _-=> lock-depth      \n", size, spaces);
+	seq_printf(s, "#%.*s|||| /                     \n", size, spaces);
 }
 
 static void print_graph_headers(struct seq_file *s)
 {
+	int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
+
+	if (lat)
+		print_lat_header(s);
+
 	/* 1st line */
-	seq_printf(s, "# ");
+	seq_printf(s, "#");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
 		seq_printf(s, "     TIME       ");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
-		seq_printf(s, "CPU");
+		seq_printf(s, " CPU");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
-		seq_printf(s, "  TASK/PID      ");
+		seq_printf(s, "  TASK/PID       ");
+	if (lat)
+		seq_printf(s, "|||||");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
 		seq_printf(s, "  DURATION   ");
 	seq_printf(s, "               FUNCTION CALLS\n");
 
 	/* 2nd line */
-	seq_printf(s, "# ");
+	seq_printf(s, "#");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
 		seq_printf(s, "      |         ");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
-		seq_printf(s, "|  ");
+		seq_printf(s, " |  ");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
-		seq_printf(s, "  |    |        ");
+		seq_printf(s, "   |    |        ");
+	if (lat)
+		seq_printf(s, "|||||");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
 		seq_printf(s, "   |   |      ");
 	seq_printf(s, "               |   |   |   |\n");
@@ -816,33 +1103,58 @@ static void print_graph_headers(struct seq_file *s)
 
 static void graph_trace_open(struct trace_iterator *iter)
 {
-	/* pid on the last trace processed */
-	pid_t *last_pid = alloc_percpu(pid_t);
+	/* pid and depth on the last trace processed */
+	struct fgraph_data *data;
 	int cpu;
 
-	if (!last_pid)
-		pr_warning("function graph tracer: not enough memory\n");
-	else
-		for_each_possible_cpu(cpu) {
-			pid_t *pid = per_cpu_ptr(last_pid, cpu);
-			*pid = -1;
-		}
+	iter->private = NULL;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto out_err;
 
-	iter->private = last_pid;
+	data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
+	if (!data->cpu_data)
+		goto out_err_free;
+
+	for_each_possible_cpu(cpu) {
+		pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
+		int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+		int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
+		*pid = -1;
+		*depth = 0;
+		*ignore = 0;
+	}
+
+	iter->private = data;
+
+	return;
+
+ out_err_free:
+	kfree(data);
+ out_err:
+	pr_warning("function graph tracer: not enough memory\n");
 }
 
 static void graph_trace_close(struct trace_iterator *iter)
 {
-	percpu_free(iter->private);
+	struct fgraph_data *data = iter->private;
+
+	if (data) {
+		free_percpu(data->cpu_data);
+		kfree(data);
+	}
 }
 
 static struct tracer graph_trace __read_mostly = {
-	.name	     	= "function_graph",
+	.name		= "function_graph",
 	.open		= graph_trace_open,
+	.pipe_open	= graph_trace_open,
 	.close		= graph_trace_close,
+	.pipe_close	= graph_trace_close,
 	.wait_pipe	= poll_wait_pipe,
-	.init	     	= graph_trace_init,
-	.reset	     	= graph_trace_reset,
+	.init		= graph_trace_init,
+	.reset		= graph_trace_reset,
 	.print_line	= print_graph_function,
 	.print_header	= print_graph_headers,
 	.flags		= &tracer_flags,
@@ -853,6 +1165,8 @@ static struct tracer graph_trace __read_mostly = {
 
 static __init int init_graph_trace(void)
 {
+	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
+
 	return register_tracer(&graph_trace);
 }