1 files changed, 246 insertions, 21 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index d31d695174a..894b50bca31 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -15,15 +15,24 @@
 
 #define TRACE_GRAPH_INDENT	2
 
+/* Flag options */
 #define TRACE_GRAPH_PRINT_OVERRUN	0x1
+#define TRACE_GRAPH_PRINT_CPU		0x2
+#define TRACE_GRAPH_PRINT_OVERHEAD	0x4
+
 static struct tracer_opt trace_opts[] = {
-	/* Display overruns or not */
-	{ TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+	/* Display overruns ? */
+	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+	/* Display CPU ? */
+	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
+	/* Display Overhead ? */
+	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
 	{ } /* Empty entry */
 };
 
 static struct tracer_flags tracer_flags = {
-	.val = 0, /* Don't display overruns by default */
+	/* Don't display overruns by default */
+	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
 	.opts = trace_opts
 };
 
@@ -52,37 +61,208 @@ 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 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);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+
 /* If the pid changed since the last trace, output this event */
 static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
 {
-	char *comm;
+	char *comm, *prev_comm;
+	pid_t prev_pid;
+	int ret;
 
 	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
 		return 1;
 
+	prev_pid = last_pid[cpu];
 	last_pid[cpu] = pid;
+
 	comm = trace_find_cmdline(pid);
+	prev_comm = trace_find_cmdline(prev_pid);
 
-	return trace_seq_printf(s, "\nCPU[%03d]"
-				    " ------------8<---------- thread %s-%d"
-				    " ------------8<----------\n\n",
-				    cpu, comm, pid);
+/*
+ * Context-switch trace line:
+
+ ------------------------------------------
+ | 1)  migration/0--1  =>  sshd-1755
+ ------------------------------------------
+
+ */
+	ret = trace_seq_printf(s,
+		" ------------------------------------------\n");
+	ret += trace_seq_printf(s, " | %d)  %s-%d  =>  %s-%d\n",
+				  cpu, prev_comm, prev_pid, comm, pid);
+	ret += trace_seq_printf(s,
+		" ------------------------------------------\n\n");
+	return ret;
 }
 
+static bool
+trace_branch_is_leaf(struct trace_iterator *iter,
+		struct ftrace_graph_ent_entry *curr)
+{
+	struct ring_buffer_iter *ring_iter;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ret_entry *next;
+
+	ring_iter = iter->buffer_iter[iter->cpu];
+
+	if (!ring_iter)
+		return false;
+
+	event = ring_buffer_iter_peek(ring_iter, NULL);
+
+	if (!event)
+		return false;
+
+	next = ring_buffer_event_data(event);
+
+	if (next->ent.type != TRACE_GRAPH_RET)
+		return false;
+
+	if (curr->ent.pid != next->ent.pid ||
+			curr->graph_ent.func != next->ret.func)
+		return false;
+
+	return true;
+}
+
+
+static inline int
+print_graph_duration(unsigned long long duration, struct trace_seq *s)
+{
+	unsigned long nsecs_rem = do_div(duration, 1000);
+	return trace_seq_printf(s, "%4llu.%3lu us |  ", duration, nsecs_rem);
+}
+
+/* Signal a overhead of time execution to the output */
+static int
+print_graph_overhead(unsigned long long duration, struct trace_seq *s)
+{
+	/* 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, "  ");
+}
+
+/* Case of a leaf function on its call entry */
 static enum print_line_t
-print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
-		  struct trace_entry *ent, int cpu)
+print_graph_entry_leaf(struct trace_iterator *iter,
+		struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
 {
-	int i;
+	struct ftrace_graph_ret_entry *ret_entry;
+	struct ftrace_graph_ret *graph_ret;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ent *call;
+	unsigned long long duration;
 	int ret;
+	int i;
 
-	if (!verif_pid(s, ent->pid, cpu))
+	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;
+
+	/* Must not exceed 8 characters: 9999.999 us */
+	if (duration > 10000000ULL)
+		duration = 9999999ULL;
+
+	/* Overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		ret = print_graph_overhead(duration, s);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Duration */
+	ret = print_graph_duration(duration, s);
+	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
+	/* Function */
+	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			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");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
+			struct trace_seq *s)
+{
+	int i;
+	int ret;
+	struct ftrace_graph_ent *call = &entry->graph_ent;
+
+	/* No overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		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, " ");
 		if (!ret)
@@ -96,37 +276,82 @@ print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
 	ret = trace_seq_printf(s, "() {\n");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
+
 	return TRACE_TYPE_HANDLED;
 }
 
 static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
+			struct trace_iterator *iter, int cpu)
+{
+	int ret;
+	struct trace_entry *ent = iter->ent;
+
+	/* Pid */
+	if (!verif_pid(s, ent->pid, cpu))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Cpu */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, cpu);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	if (trace_branch_is_leaf(iter, field))
+		return print_graph_entry_leaf(iter, field, s);
+	else
+		return print_graph_entry_nested(field, s);
+
+}
+
+static enum print_line_t
 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 		   struct trace_entry *ent, int cpu)
 {
 	int i;
 	int ret;
+	unsigned long long duration = trace->rettime - trace->calltime;
+
+	/* Must not exceed 8 characters: xxxx.yyy us */
+	if (duration > 10000000ULL)
+		duration = 9999999ULL;
 
+	/* Pid */
 	if (!verif_pid(s, ent->pid, cpu))
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
+	/* Cpu */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, cpu);
+		if (!ret)
+			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;
+	}
+
+	/* Duration */
+	ret = print_graph_duration(duration, s);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	/* Closing brace */
 	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
 		ret = trace_seq_printf(s, " ");
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = trace_seq_printf(s, "} ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime);
+	ret = trace_seq_printf(s, "}\n");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
+	/* Overrun */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
 		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
 					trace->overrun);
@@ -146,7 +371,7 @@ print_graph_function(struct trace_iterator *iter)
 	case TRACE_GRAPH_ENT: {
 		struct ftrace_graph_ent_entry *field;
 		trace_assign_type(field, entry);
-		return print_graph_entry(&field->graph_ent, s, entry,
+		return print_graph_entry(field, s, iter,
 					 iter->cpu);
 	}
 	case TRACE_GRAPH_RET: {
@@ -160,7 +385,7 @@ print_graph_function(struct trace_iterator *iter)
 }
 
 static struct tracer graph_trace __read_mostly = {
-	.name	     = "function-graph",
+	.name	     = "function_graph",
 	.init	     = graph_trace_init,
 	.reset	     = graph_trace_reset,
 	.print_line = print_graph_function,