X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace_functions_graph.c;h=79f4bac99a94a767569a8247091eb7fd196fae7b;hb=254c8c2dbf0e06a560a5814eb90cb628adb2de66;hp=32b7fb9a19df8ac3d6792cadaec56b1009c061cf;hpb=1fd8f2a3f9a91b287a876cef830b21baafc8a799;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 32b7fb9..79f4bac 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -1,7 +1,7 @@
 /*
  *
  * Function graph tracer.
- * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
  * Mostly borrowed from function tracer which
  * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
  *
@@ -9,9 +9,28 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/slab.h>
 #include <linux/fs.h>
 
 #include "trace.h"
+#include "trace_output.h"
+
+struct fgraph_cpu_data {
+	pid_t		last_pid;
+	int		depth;
+	int		ignore;
+	unsigned long	enter_funcs[FTRACE_RETFUNC_DEPTH];
+};
+
+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
 
@@ -20,9 +39,11 @@
 #define TRACE_GRAPH_PRINT_CPU		0x2
 #define TRACE_GRAPH_PRINT_OVERHEAD	0x4
 #define TRACE_GRAPH_PRINT_PROC		0x8
+#define TRACE_GRAPH_PRINT_DURATION	0x10
+#define TRACE_GRAPH_PRINT_ABS_TIME	0x20
 
 static struct tracer_opt trace_opts[] = {
-	/* Display overruns ? */
+	/* Display overruns? (for self-debug purpose) */
 	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
 	/* Display CPU ? */
 	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
@@ -30,27 +51,274 @@ static struct tracer_opt trace_opts[] = {
 	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
 	/* Display proc name/pid */
 	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
+	/* Display duration of execution */
+	{ TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
+	/* Display absolute time of an entry */
+	{ TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
 	{ } /* Empty entry */
 };
 
 static struct tracer_flags tracer_flags = {
 	/* Don't display overruns and proc by default */
-	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
+	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
+	       TRACE_GRAPH_PRINT_DURATION,
 	.opts = trace_opts
 };
 
-/* pid on the last trace processed */
-static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
+static struct trace_array *graph_array;
 
-static int graph_trace_init(struct trace_array *tr)
+
+/* Add a function return address to the trace stack on thread info.*/
+int
+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 = 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.*/
+static void
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
+			unsigned long frame_pointer)
+{
+	int index;
+
+	index = current->curr_ret_stack;
+
+	if (unlikely(index < 0)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic, otherwise we have no where to go */
+		*ret = (unsigned long)panic;
+		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;
+}
+
+/*
+ * Send the trace to the ring-buffer.
+ * @return the original return address.
+ */
+unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
+{
+	struct ftrace_graph_ret trace;
+	unsigned long ret;
+
+	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();
+		WARN_ON(1);
+		/* Might as well panic. What else to do? */
+		ret = (unsigned long)panic;
+	}
+
+	return ret;
+}
+
+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(__this_cpu_read(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 (!ftrace_trace_task(current))
+		return 0;
+
+	/* trace it when it is-nested-in or is a function enabled. */
+	if (!(trace->depth || 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;
+	}
+
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
+{
+	if (tracing_thresh)
+		return 1;
+	else
+		return trace_graph_entry(trace);
+}
+
+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(__this_cpu_read(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);
+	}
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+
+void set_graph_array(struct trace_array *tr)
+{
+	graph_array = tr;
+
+	/* Make graph_array visible before we start tracing */
+
+	smp_mb();
+}
+
+void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
 {
-	int cpu, ret;
+	if (tracing_thresh &&
+	    (trace->rettime - trace->calltime < tracing_thresh))
+		return;
+	else
+		trace_graph_return(trace);
+}
 
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
+static int graph_trace_init(struct trace_array *tr)
+{
+	int ret;
 
-	ret = register_ftrace_graph(&trace_graph_return,
-					&trace_graph_entry);
+	set_graph_array(tr);
+	if (tracing_thresh)
+		ret = register_ftrace_graph(&trace_graph_thresh_return,
+					    &trace_graph_thresh_entry);
+	else
+		ret = register_ftrace_graph(&trace_graph_return,
+					    &trace_graph_entry);
 	if (ret)
 		return ret;
 	tracing_start_cmdline_record();
@@ -64,43 +332,19 @@ static void graph_trace_reset(struct trace_array *tr)
 	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(cpus_weight_nr(cpu_online_map));
-
 
 	/*
 	 * 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;
 
@@ -112,15 +356,15 @@ 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);
 
@@ -151,19 +395,36 @@ 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)
+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_pid[cpu] != -1 && last_pid[cpu] == pid)
+	if (!data)
 		return TRACE_TYPE_HANDLED;
 
-	prev_pid = last_pid[cpu];
-	last_pid[cpu] = pid;
+	last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
 
+	if (*last_pid == pid)
+		return TRACE_TYPE_HANDLED;
+
+	prev_pid = *last_pid;
+	*last_pid = pid;
+
+	if (prev_pid == -1)
+		return TRACE_TYPE_HANDLED;
 /*
  * Context-switch trace line:
 
@@ -175,65 +436,192 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu)
 	ret = trace_seq_printf(s,
 		" ------------------------------------------\n");
 	if (!ret)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = print_graph_cpu(s, cpu);
 	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = print_graph_proc(s, prev_pid);
 	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = trace_seq_printf(s, " => ");
 	if (!ret)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = print_graph_proc(s, pid);
 	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = trace_seq_printf(s,
 		"\n ------------------------------------------\n\n");
 	if (!ret)
-		TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_PARTIAL_LINE;
 
-	return ret;
+	return TRACE_TYPE_HANDLED;
 }
 
-static bool
-trace_branch_is_leaf(struct trace_iterator *iter,
+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 (!ring_iter)
-		return false;
+	/*
+	 * 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, NULL);
+			event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+						 NULL, NULL);
+		}
 
-	event = ring_buffer_iter_peek(ring_iter, NULL);
+		if (!event)
+			return NULL;
 
-	if (!event)
-		return false;
+		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 false;
+		return NULL;
 
 	if (curr->ent.pid != next->ent.pid ||
 			curr->graph_ent.func != next->ret.func)
-		return false;
+		return NULL;
+
+	/* this is a leaf, now advance the iterator */
+	if (ring_iter)
+		ring_buffer_read(ring_iter, NULL);
 
-	return true;
+	return next;
 }
 
+/* Signal a overhead of time execution to the output */
+static int
+print_graph_overhead(unsigned long long duration, struct trace_seq *s,
+		     u32 flags)
+{
+	/* If duration disappear, we don't need anything */
+	if (!(flags & TRACE_GRAPH_PRINT_DURATION))
+		return 1;
+
+	/* Non nested entry or return */
+	if (duration == -1)
+		return trace_seq_printf(s, "  ");
+
+	if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
+		/* Duration exceeded 100 msecs */
+		if (duration > 100000ULL)
+			return trace_seq_printf(s, "! ");
+
+		/* Duration exceeded 10 msecs */
+		if (duration > 10000ULL)
+			return trace_seq_printf(s, "+ ");
+	}
+
+	return trace_seq_printf(s, "  ");
+}
+
+static int print_graph_abs_time(u64 t, struct trace_seq *s)
+{
+	unsigned long usecs_rem;
+
+	usecs_rem = do_div(t, NSEC_PER_SEC);
+	usecs_rem /= 1000;
+
+	return trace_seq_printf(s, "%5lu.%06lu |  ",
+			(unsigned long)t, usecs_rem);
+}
 
 static enum print_line_t
-print_graph_duration(unsigned long long duration, struct trace_seq *s)
+print_graph_irq(struct trace_iterator *iter, unsigned long addr,
+		enum trace_type type, int cpu, pid_t pid, u32 flags)
+{
+	int ret;
+	struct trace_seq *s = &iter->seq;
+
+	if (addr < (unsigned long)__irqentry_text_start ||
+		addr >= (unsigned long)__irqentry_text_end)
+		return TRACE_TYPE_UNHANDLED;
+
+	/* Absolute time */
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
+		ret = print_graph_abs_time(iter->ts, s);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Cpu */
+	if (flags & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (flags & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+		ret = trace_seq_printf(s, " | ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* No overhead */
+	ret = print_graph_overhead(-1, s, flags);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	if (type == TRACE_GRAPH_ENT)
+		ret = trace_seq_printf(s, "==========>");
+	else
+		ret = trace_seq_printf(s, "<==========");
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Don't close the duration column if haven't one */
+	if (flags & TRACE_GRAPH_PRINT_DURATION)
+		trace_seq_printf(s, " |");
+	ret = trace_seq_printf(s, "\n");
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+}
+
+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' */
@@ -245,7 +633,7 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s)
 	sprintf(msecs_str, "%lu", (unsigned long) duration);
 
 	/* Print msecs */
-	ret = trace_seq_printf(s, msecs_str);
+	ret = trace_seq_printf(s, "%s", msecs_str);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -270,60 +658,73 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s)
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
-
-	ret = trace_seq_printf(s, "|  ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
 	return TRACE_TYPE_HANDLED;
-
 }
 
-/* Signal a overhead of time execution to the output */
-static int
-print_graph_overhead(unsigned long long duration, struct trace_seq *s)
+static enum print_line_t
+print_graph_duration(unsigned long long duration, struct trace_seq *s)
 {
-	/* Duration exceeded 100 msecs */
-	if (duration > 100000ULL)
-		return trace_seq_printf(s, "! ");
+	int ret;
 
-	/* Duration exceeded 10 msecs */
-	if (duration > 10000ULL)
-		return trace_seq_printf(s, "+ ");
+	ret = trace_print_graph_duration(duration, s);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
 
-	return trace_seq_printf(s, "  ");
+	ret = trace_seq_printf(s, "|  ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
 }
 
 /* Case of a leaf function on its call entry */
 static enum print_line_t
 print_graph_entry_leaf(struct trace_iterator *iter,
-		struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
+		struct ftrace_graph_ent_entry *entry,
+		struct ftrace_graph_ret_entry *ret_entry,
+		struct trace_seq *s, u32 flags)
 {
-	struct ftrace_graph_ret_entry *ret_entry;
+	struct fgraph_data *data = iter->private;
 	struct ftrace_graph_ret *graph_ret;
-	struct ring_buffer_event *event;
 	struct ftrace_graph_ent *call;
 	unsigned long long duration;
 	int ret;
 	int i;
 
-	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
-	ret_entry = ring_buffer_event_data(event);
 	graph_ret = &ret_entry->ret;
 	call = &entry->graph_ent;
 	duration = graph_ret->rettime - graph_ret->calltime;
 
-	/* Overhead */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
-		ret = print_graph_overhead(duration, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+	if (data) {
+		struct fgraph_cpu_data *cpu_data;
+		int cpu = iter->cpu;
+
+		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
+
+		/*
+		 * Comments display at + 1 to depth. Since
+		 * this is a leaf function, keep the comments
+		 * equal to this depth.
+		 */
+		cpu_data->depth = call->depth - 1;
+
+		/* No need to keep this function around for this depth */
+		if (call->depth < FTRACE_RETFUNC_DEPTH)
+			cpu_data->enter_funcs[call->depth] = 0;
 	}
 
-	/* Duration */
-	ret = print_graph_duration(duration, s);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
+	/* Overhead */
+	ret = print_graph_overhead(duration, s, flags);
+	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	/* Duration */
+	if (flags & TRACE_GRAPH_PRINT_DURATION) {
+		ret = print_graph_duration(duration, s);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
 	/* Function */
 	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 		ret = trace_seq_printf(s, " ");
@@ -331,11 +732,7 @@ 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;
 
@@ -343,23 +740,39 @@ 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)
+print_graph_entry_nested(struct trace_iterator *iter,
+			 struct ftrace_graph_ent_entry *entry,
+			 struct trace_seq *s, int cpu, u32 flags)
 {
-	int i;
-	int ret;
 	struct ftrace_graph_ent *call = &entry->graph_ent;
+	struct fgraph_data *data = iter->private;
+	int ret;
+	int i;
+
+	if (data) {
+		struct fgraph_cpu_data *cpu_data;
+		int cpu = iter->cpu;
+
+		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
+		cpu_data->depth = call->depth;
+
+		/* Save this function pointer to see if the exit matches */
+		if (call->depth < FTRACE_RETFUNC_DEPTH)
+			cpu_data->enter_funcs[call->depth] = call->func;
+	}
 
 	/* No overhead */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
-		ret = trace_seq_printf(s, "  ");
+	ret = print_graph_overhead(-1, s, flags);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* No time */
+	if (flags & TRACE_GRAPH_PRINT_DURATION) {
+		ret = trace_seq_printf(s, "            |  ");
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	/* No time */
-	ret = trace_seq_printf(s, "            |  ");
-
 	/* Function */
 	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 		ret = trace_seq_printf(s, " ");
@@ -367,37 +780,53 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = seq_print_ip_sym(s, call->func, 0);
+	ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	ret = trace_seq_printf(s, "() {\n");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
+	/*
+	 * we already consumed the current entry to check the next one
+	 * and see if this is a leaf.
+	 */
+	return TRACE_TYPE_NO_CONSUME;
 }
 
 static enum print_line_t
-print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
-			struct trace_iterator *iter, int cpu)
+print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
+		     int type, unsigned long addr, u32 flags)
 {
-	int ret;
+	struct fgraph_data *data = iter->private;
 	struct trace_entry *ent = iter->ent;
+	int cpu = iter->cpu;
+	int ret;
 
 	/* Pid */
-	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
+	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	if (type) {
+		/* Interrupt */
+		ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Absolute time */
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
+		ret = print_graph_abs_time(iter->ts, s);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
 	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+	if (flags & TRACE_GRAPH_PRINT_CPU) {
 		ret = print_graph_cpu(s, cpu);
 		if (ret == TRACE_TYPE_PARTIAL_LINE)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
 	/* Proc */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+	if (flags & TRACE_GRAPH_PRINT_PROC) {
 		ret = print_graph_proc(s, ent->pid);
 		if (ret == TRACE_TYPE_PARTIAL_LINE)
 			return TRACE_TYPE_PARTIAL_LINE;
@@ -407,54 +836,97 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	if (trace_branch_is_leaf(iter, field))
-		return print_graph_entry_leaf(iter, field, s);
+	/* 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, u32 flags)
+{
+	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, flags))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	leaf_ret = get_return_for_leaf(iter, field);
+	if (leaf_ret)
+		ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
 	else
-		return print_graph_entry_nested(field, s);
+		ret = print_graph_entry_nested(iter, field, s, cpu, flags);
+
+	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, int cpu)
+		   struct trace_entry *ent, struct trace_iterator *iter,
+		   u32 flags)
 {
-	int i;
-	int ret;
 	unsigned long long duration = trace->rettime - trace->calltime;
+	struct fgraph_data *data = iter->private;
+	pid_t pid = ent->pid;
+	int cpu = iter->cpu;
+	int func_match = 1;
+	int ret;
+	int i;
 
-	/* Pid */
-	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	if (data) {
+		struct fgraph_cpu_data *cpu_data;
+		int cpu = iter->cpu;
 
-	/* 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;
-	}
+		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
 
-	/* 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;
+		/*
+		 * 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.
+		 */
+		cpu_data->depth = trace->depth - 1;
 
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+		if (trace->depth < FTRACE_RETFUNC_DEPTH) {
+			if (cpu_data->enter_funcs[trace->depth] != trace->func)
+				func_match = 0;
+			cpu_data->enter_funcs[trace->depth] = 0;
+		}
 	}
 
+	if (print_graph_prologue(iter, s, 0, 0, flags))
+		return TRACE_TYPE_PARTIAL_LINE;
+
 	/* Overhead */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
-		ret = print_graph_overhead(duration, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	ret = print_graph_overhead(duration, s, flags);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Duration */
-	ret = print_graph_duration(duration, s);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	if (flags & TRACE_GRAPH_PRINT_DURATION) {
+		ret = print_graph_duration(duration, s);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
 
 	/* Closing brace */
 	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
@@ -463,76 +935,106 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = trace_seq_printf(s, "}\n");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	/*
+	 * If the return function does not have a matching entry,
+	 * then the entry was lost. Instead of just printing
+	 * the '}' and letting the user guess what function this
+	 * belongs to, write out the function name.
+	 */
+	if (func_match) {
+		ret = trace_seq_printf(s, "}\n");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	} else {
+		ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
 
 	/* Overrun */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
+	if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
 		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
 					trace->overrun);
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
+
+	ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
+			      cpu, pid, flags);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
 	return TRACE_TYPE_HANDLED;
 }
 
 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, u32 flags)
 {
-	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 i;
 
-	/* Pid */
-	if (verif_pid(s, ent->pid, iter->cpu) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, iter->cpu);
-		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, ent->pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
+	if (data)
+		depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
 
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (print_graph_prologue(iter, s, 0, 0, flags))
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* No overhead */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
-		ret = trace_seq_printf(s, "  ");
+	ret = print_graph_overhead(-1, s, flags);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* No time */
+	if (flags & TRACE_GRAPH_PRINT_DURATION) {
+		ret = trace_seq_printf(s, "            |  ");
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	/* No time */
-	ret = trace_seq_printf(s, "            |  ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
 	/* 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;
 
-	if (ent->flags & TRACE_FLAG_CONT)
-		trace_seq_print_cont(s, iter);
+	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->funcs->trace(iter, sym_flags, event);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+	}
+
+	/* Strip ending newline */
+	if (s->buffer[s->len - 1] == '\n') {
+		s->buffer[s->len - 1] = '\0';
+		s->len--;
+	}
 
 	ret = trace_seq_printf(s, " */\n");
 	if (!ret)
@@ -543,43 +1045,232 @@ print_graph_comment(struct print_entry *trace, struct trace_seq *s,
 
 
 enum print_line_t
-print_graph_function(struct trace_iterator *iter)
+print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 {
-	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, flags);
+		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,
-					 iter->cpu);
+		saved = *field;
+		return print_graph_entry(&saved, s, iter, flags);
 	}
 	case TRACE_GRAPH_RET: {
 		struct ftrace_graph_ret_entry *field;
 		trace_assign_type(field, entry);
-		return print_graph_return(&field->ret, s, entry, iter->cpu);
-	}
-	case TRACE_PRINT: {
-		struct print_entry *field;
-		trace_assign_type(field, entry);
-		return print_graph_comment(field, s, entry, iter);
+		return print_graph_return(&field->ret, s, entry, iter, flags);
 	}
-	default:
+	case TRACE_STACK:
+	case TRACE_FN:
+		/* dont trace stack and functions as comments */
 		return TRACE_TYPE_UNHANDLED;
+
+	default:
+		return print_graph_comment(s, entry, iter, flags);
 	}
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_function(struct trace_iterator *iter)
+{
+	return print_graph_function_flags(iter, tracer_flags.val);
 }
 
+static enum print_line_t
+print_graph_function_event(struct trace_iterator *iter, int flags,
+			   struct trace_event *event)
+{
+	return print_graph_function(iter);
+}
+
+static void print_lat_header(struct seq_file *s, u32 flags)
+{
+	static const char spaces[] = "                "	/* 16 spaces */
+		"    "					/* 4 spaces */
+		"                 ";			/* 17 spaces */
+	int size = 0;
+
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
+		size += 16;
+	if (flags & TRACE_GRAPH_PRINT_CPU)
+		size += 4;
+	if (flags & 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);
+}
+
+void print_graph_headers_flags(struct seq_file *s, u32 flags)
+{
+	int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
+
+	if (lat)
+		print_lat_header(s, flags);
+
+	/* 1st line */
+	seq_printf(s, "#");
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
+		seq_printf(s, "     TIME       ");
+	if (flags & TRACE_GRAPH_PRINT_CPU)
+		seq_printf(s, " CPU");
+	if (flags & TRACE_GRAPH_PRINT_PROC)
+		seq_printf(s, "  TASK/PID       ");
+	if (lat)
+		seq_printf(s, "|||||");
+	if (flags & TRACE_GRAPH_PRINT_DURATION)
+		seq_printf(s, "  DURATION   ");
+	seq_printf(s, "               FUNCTION CALLS\n");
+
+	/* 2nd line */
+	seq_printf(s, "#");
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
+		seq_printf(s, "      |         ");
+	if (flags & TRACE_GRAPH_PRINT_CPU)
+		seq_printf(s, " |  ");
+	if (flags & TRACE_GRAPH_PRINT_PROC)
+		seq_printf(s, "   |    |        ");
+	if (lat)
+		seq_printf(s, "|||||");
+	if (flags & TRACE_GRAPH_PRINT_DURATION)
+		seq_printf(s, "   |   |      ");
+	seq_printf(s, "               |   |   |   |\n");
+}
+
+void print_graph_headers(struct seq_file *s)
+{
+	print_graph_headers_flags(s, tracer_flags.val);
+}
+
+void graph_trace_open(struct trace_iterator *iter)
+{
+	/* pid and depth on the last trace processed */
+	struct fgraph_data *data;
+	int cpu;
+
+	iter->private = NULL;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto out_err;
+
+	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");
+}
+
+void graph_trace_close(struct trace_iterator *iter)
+{
+	struct fgraph_data *data = iter->private;
+
+	if (data) {
+		free_percpu(data->cpu_data);
+		kfree(data);
+	}
+}
+
+static struct trace_event_functions graph_functions = {
+	.trace		= print_graph_function_event,
+};
+
+static struct trace_event graph_trace_entry_event = {
+	.type		= TRACE_GRAPH_ENT,
+	.funcs		= &graph_functions,
+};
+
+static struct trace_event graph_trace_ret_event = {
+	.type		= TRACE_GRAPH_RET,
+	.funcs		= &graph_functions
+};
+
 static struct tracer graph_trace __read_mostly = {
-	.name	     = "function_graph",
-	.init	     = graph_trace_init,
-	.reset	     = graph_trace_reset,
-	.print_line = print_graph_function,
+	.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,
+	.print_line	= print_graph_function,
+	.print_header	= print_graph_headers,
 	.flags		= &tracer_flags,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest	= trace_selftest_startup_function_graph,
+#endif
 };
 
 static __init int init_graph_trace(void)
 {
+	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
+
+	if (!register_ftrace_event(&graph_trace_entry_event)) {
+		pr_warning("Warning: could not register graph trace events\n");
+		return 1;
+	}
+
+	if (!register_ftrace_event(&graph_trace_ret_event)) {
+		pr_warning("Warning: could not register graph trace events\n");
+		return 1;
+	}
+
 	return register_tracer(&graph_trace);
 }