[PATCH 0/4] tracing: function graph output for preempt/irqs-off tracers

[PATCH 0/4] tracing: function graph output for preempt/irqs-off tracers

[Jiri Olsa]

hi,

I'm sending reworked version of the graph output support for
preemptirqsoff/preemptoff/irqsoff tracers.

I made the graph output as an output event, so it could be shared
within tracers - patch 1/4.

I also added raw trace output for graph tracer. I have this one around
for long time and it was quite handy for investigating graph tracer issues.
(patch 4/4)


attached patches:
- 1/4 adding ftrace events for graph tracer
- 2/4 graph output support for irqsoff tracer
- 3/4 graph output support for preemptirqsoff/preemptoff tracers
- 4/4 raw output for graph tracer

wbr,
jirka
---
 kernel/trace/trace.c                 |    2 +-
 kernel/trace/trace.h                 |   11 ++-
 kernel/trace/trace_functions_graph.c |  117 +++++++++++++++++++----
 kernel/trace/trace_irqsoff.c         |  174 ++++++++++++++++++++++++++++++++--
 4 files changed, 277 insertions(+), 27 deletions(-)

[PATCH 1/4] tracing: adding ftrace events for graph tracer

[Jiri Olsa]

hi,

this patch adds ftrace events for graph tracer, so the graph output
could be shared within other tracers.

wbr,
jirka


Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 kernel/trace/trace.h                 |    3 ++-
 kernel/trace/trace_functions_graph.c |   25 ++++++++++++++++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b477fce..1feda87 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -490,7 +490,8 @@ extern int trace_clock_id;
 
 /* Standard output formatting function used for function return traces */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-extern enum print_line_t print_graph_function(struct trace_iterator *iter);
+extern enum print_line_t print_graph_function(struct trace_iterator *iter,
+					      int flags);
 extern enum print_line_t
 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 616b135..41cec17 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -38,7 +38,7 @@ struct fgraph_data {
 #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
+#define TRACE_GRAPH_PRINT_ABS_TIME	0x20
 
 static struct tracer_opt trace_opts[] = {
 	/* Display overruns? (for self-debug purpose) */
@@ -985,7 +985,7 @@ print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
 
 
 enum print_line_t
-print_graph_function(struct trace_iterator *iter)
+print_graph_function(struct trace_iterator *iter, int flags)
 {
 	struct ftrace_graph_ent_entry *field;
 	struct fgraph_data *data = iter->private;
@@ -1143,6 +1143,16 @@ static void graph_trace_close(struct trace_iterator *iter)
 	}
 }
 
+static struct trace_event graph_trace_entry_event = {
+	.type		= TRACE_GRAPH_ENT,
+	.trace		= print_graph_function,
+};
+
+static struct trace_event graph_trace_ret_event = {
+	.type		= TRACE_GRAPH_RET,
+	.trace		= print_graph_function,
+};
+
 static struct tracer graph_trace __read_mostly = {
 	.name		= "function_graph",
 	.open		= graph_trace_open,
@@ -1152,7 +1162,6 @@ static struct tracer graph_trace __read_mostly = {
 	.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
@@ -1164,6 +1173,16 @@ 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);
 }
 
-- 
1.6.6

[PATCH 2/4] tracing: graph output support for irqsoff tracer

[Jiri Olsa]

hi,

when I was using irqsoff tracer, I thought it could be any use
to see the disabled IRQs flow output same way as function graph output.

The graph output is enabled by setting new 'display-graph' trace option
of irqsoff tracer.

It looks like this:

[root@dell-pe1950-05 tracing]# echo irqsoff-graph > ./trace_options 
[root@dell-pe1950-05 tracing]# cat ./trace
# tracer: irqsoff
#
#      _-----=> irqs-off        
#     / _----=> need-resched    
#    | / _---=> hardirq/softirq 
#    || / _--=> preempt-depth   
#    ||| / _-=> lock-depth      
#    |||| /                     
# CPU|||||  DURATION                  FUNCTION CALLS
# |  |||||   |   |                     |   |   |   |
hald-add-1048    3d...0    0us : _raw_spin_lock_irqsave <-scsi_dispatch_cmd
 3)  d...0              |      ata_scsi_queuecmd() {
 3)  d...0  0.318 us    |        _raw_spin_lock();
 3)  d...0              |        ata_scsi_find_dev() {
 3)  d...0              |          __ata_scsi_find_dev() {
 3)  d...0  0.273 us    |            ata_find_dev();
 3)  d...0  0.798 us    |          }
 3)  d...0  1.419 us    |        }
 3)  d...0              |        __ata_scsi_queuecmd() {
 3)  d...0              |          ata_qc_new_init() {
 3)  d...0              |            ata_qc_reinit() {
 3)  d...0  0.258 us    |              ata_tf_init();
 3)  d...0  0.784 us    |            }
 3)  d...0  1.441 us    |          }
 3)  d...0  0.348 us    |          atapi_xlat();
 3)  d...0              |          ata_qc_issue() {
...

SNIP

...
 3)  d...0+ 31.244 us   |                }
 3)  d...0+ 32.393 us   |              }
 3)  d...0+ 99.146 us   |            }
 3)  d...0! 100.455 us  |          }
 3)  d...0! 103.669 us  |        }
 3)  d...0  0.267 us    |        _raw_spin_lock();
 3)  d...0! 107.264 us  |      }
 3)  d...0              |      spin_unlock_irqrestore() {
 3)  d...0              |        _raw_spin_unlock_irqrestore() {
hald-add-1048    3d...0  109us : _raw_spin_unlock_irqrestore <-return_to_handler
hald-add-1048    3d...0  109us : trace_hardirqs_on <-return_to_handler
hald-add-1048    3d...0  109us : <stack trace>
 => trace_hardirqs_on
 => _raw_spin_unlock_irqrestore
 => return_to_handler
 => scsi_dispatch_cmd
 => return_to_handler
 => __generic_unplug_device
 => scsi_request_fn
 => return_to_handler
[root@dell-pe1950-05 tracing]#

wbr,
jirka


Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 kernel/trace/trace.h                 |    8 ++
 kernel/trace/trace_functions_graph.c |   25 ++----
 kernel/trace/trace_irqsoff.c         |  162 ++++++++++++++++++++++++++++++++--
 3 files changed, 172 insertions(+), 23 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1feda87..d2a42c9 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -494,6 +494,14 @@ extern enum print_line_t print_graph_function(struct trace_iterator *iter,
 					      int flags);
 extern enum print_line_t
 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
+void graph_trace_open(struct trace_iterator *iter);
+void graph_trace_close(struct trace_iterator *iter);
+int __trace_graph_entry(struct trace_array *tr, struct ftrace_graph_ent *trace,
+			unsigned long flags, int pc);
+void __trace_graph_return(struct trace_array *tr,
+			struct ftrace_graph_ret *trace,
+			unsigned long flags, int pc);
+
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 /* TODO: make this variable */
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 41cec17..eca09b3 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -177,7 +177,7 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 	return ret;
 }
 
-static int __trace_graph_entry(struct trace_array *tr,
+int __trace_graph_entry(struct trace_array *tr,
 				struct ftrace_graph_ent *trace,
 				unsigned long flags,
 				int pc)
@@ -236,7 +236,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 	return ret;
 }
 
-static void __trace_graph_return(struct trace_array *tr,
+void __trace_graph_return(struct trace_array *tr,
 				struct ftrace_graph_ret *trace,
 				unsigned long flags,
 				int pc)
@@ -911,9 +911,7 @@ static enum print_line_t
 print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
 		    struct trace_iterator *iter)
 {
-	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;
@@ -960,14 +958,6 @@ print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
 		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 */
@@ -1033,8 +1023,11 @@ print_graph_function(struct trace_iterator *iter, int flags)
 		trace_assign_type(field, entry);
 		return print_graph_return(&field->ret, s, entry, iter);
 	}
-	default:
+	case TRACE_BPRINT:
+	case TRACE_PRINT:
 		return print_graph_comment(s, entry, iter);
+	default:
+		return TRACE_TYPE_UNHANDLED;
 	}
 
 	return TRACE_TYPE_HANDLED;
@@ -1062,7 +1055,7 @@ static void print_lat_header(struct seq_file *s)
 	seq_printf(s, "#%.*s|||| /                     \n", size, spaces);
 }
 
-static void print_graph_headers(struct seq_file *s)
+void print_graph_headers(struct seq_file *s)
 {
 	int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
 
@@ -1098,7 +1091,7 @@ static void print_graph_headers(struct seq_file *s)
 	seq_printf(s, "               |   |   |   |\n");
 }
 
-static void graph_trace_open(struct trace_iterator *iter)
+void graph_trace_open(struct trace_iterator *iter)
 {
 	/* pid and depth on the last trace processed */
 	struct fgraph_data *data;
@@ -1133,7 +1126,7 @@ static void graph_trace_open(struct trace_iterator *iter)
 	pr_warning("function graph tracer: not enough memory\n");
 }
 
-static void graph_trace_close(struct trace_iterator *iter)
+void graph_trace_close(struct trace_iterator *iter)
 {
 	struct fgraph_data *data = iter->private;
 
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 2974bc7..f3f43fc 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -34,6 +34,9 @@ static int trace_type __read_mostly;
 
 static int save_lat_flag;
 
+static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
+static int start_irqsoff_tracer(struct trace_array *tr, int graph);
+
 #ifdef CONFIG_PREEMPT_TRACER
 static inline int
 preempt_trace(void)
@@ -55,6 +58,23 @@ irq_trace(void)
 # define irq_trace() (0)
 #endif
 
+#define TRACE_IRQSOFF_GRAPH	1
+
+static struct tracer_opt trace_opts[] = {
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	/* display latency trace as call graph */
+	{ TRACER_OPT(irqsoff-graph, TRACE_IRQSOFF_GRAPH) },
+#endif
+	{ } /* Empty entry */
+};
+
+static struct tracer_flags tracer_flags = {
+	.val = 0,
+	.opts = trace_opts,
+};
+
+#define is_graph() (tracer_flags.val & TRACE_IRQSOFF_GRAPH)
+
 /*
  * Sequence count - we record it when starting a measurement and
  * skip the latency if the sequence has changed - some other section
@@ -108,6 +128,109 @@ static struct ftrace_ops trace_ops __read_mostly =
 };
 #endif /* CONFIG_FUNCTION_TRACER */
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
+{
+	int cpu;
+
+	if (!(bit & TRACE_IRQSOFF_GRAPH))
+		return -EINVAL;
+
+	if (!(is_graph() ^ set))
+		return 0;
+
+	stop_irqsoff_tracer(irqsoff_trace, !set);
+
+	for_each_possible_cpu(cpu)
+		per_cpu(tracing_cpu, cpu) = 0;
+
+	tracing_max_latency = 0;
+	tracing_reset_online_cpus(irqsoff_trace);
+
+	return start_irqsoff_tracer(irqsoff_trace, set);
+}
+
+static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
+{
+	struct trace_array *tr = irqsoff_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int ret;
+	int cpu;
+	int pc;
+
+	cpu = raw_smp_processor_id();
+	if (likely(!per_cpu(tracing_cpu, cpu)))
+		return 0;
+
+	local_save_flags(flags);
+	/* slight chance to get a false positive on tracing_cpu */
+	if (!irqs_disabled_flags(flags))
+		return 0;
+
+	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);
+	return ret;
+}
+
+static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
+{
+	struct trace_array *tr = irqsoff_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	cpu = raw_smp_processor_id();
+	if (likely(!per_cpu(tracing_cpu, cpu)))
+		return;
+
+	local_save_flags(flags);
+	/* slight chance to get a false positive on tracing_cpu */
+	if (!irqs_disabled_flags(flags))
+		return;
+
+	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);
+}
+
+static void irqsoff_trace_open(struct trace_iterator *iter)
+{
+	if (is_graph())
+		graph_trace_open(iter);
+
+}
+
+static void irqsoff_trace_close(struct trace_iterator *iter)
+{
+	if (iter->private)
+		graph_trace_close(iter);
+}
+
+#else
+static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
 /*
  * Should this new latency be reported/recorded?
  */
@@ -347,19 +470,36 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
 }
 #endif /* CONFIG_PREEMPT_TRACER */
 
-static void start_irqsoff_tracer(struct trace_array *tr)
+static int start_irqsoff_tracer(struct trace_array *tr, int graph)
 {
-	register_ftrace_function(&trace_ops);
-	if (tracing_is_enabled())
+	int ret = 0;
+
+	if (!graph)
+		ret = register_ftrace_function(&trace_ops);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	else
+		ret = register_ftrace_graph(&irqsoff_graph_return,
+					    &irqsoff_graph_entry);
+#endif
+
+	if (!ret && tracing_is_enabled())
 		tracer_enabled = 1;
 	else
 		tracer_enabled = 0;
+
+	return ret;
 }
 
-static void stop_irqsoff_tracer(struct trace_array *tr)
+static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
 {
 	tracer_enabled = 0;
-	unregister_ftrace_function(&trace_ops);
+
+	if (!graph)
+		unregister_ftrace_function(&trace_ops);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	else
+		unregister_ftrace_graph();
+#endif
 }
 
 static void __irqsoff_tracer_init(struct trace_array *tr)
@@ -372,12 +512,14 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 	/* make sure that the tracer is visible */
 	smp_wmb();
 	tracing_reset_online_cpus(tr);
-	start_irqsoff_tracer(tr);
+
+	if (start_irqsoff_tracer(tr, is_graph()))
+		printk(KERN_ERR "failed to start irqsoff tracer\n");
 }
 
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
-	stop_irqsoff_tracer(tr);
+	stop_irqsoff_tracer(tr, is_graph());
 
 	if (!save_lat_flag)
 		trace_flags &= ~TRACE_ITER_LATENCY_FMT;
@@ -408,10 +550,16 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.reset		= irqsoff_tracer_reset,
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
+	.flags		= &tracer_flags,
 	.print_max	= 1,
+	.set_flag	= irqsoff_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_irqsoff,
 #endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.open           = irqsoff_trace_open,
+	.close          = irqsoff_trace_close,
+#endif
 };
 # define register_irqsoff(trace) register_tracer(&trace)
 #else
-- 
1.6.6

[PATCH 3/4] tracing: graph output support for preemptirqsoff/preemptoff tracers

[Jiri Olsa]

hi,

adding support for graph output for preemptirqsoff/preemptoff tracers.

wbr,
jirka


Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 kernel/trace/trace_irqsoff.c |   22 +++++++++++++++++-----
 1 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index f3f43fc..15e05c9 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -58,12 +58,12 @@ irq_trace(void)
 # define irq_trace() (0)
 #endif
 
-#define TRACE_IRQSOFF_GRAPH	1
+#define TRACE_DISPLAY_GRAPH	1
 
 static struct tracer_opt trace_opts[] = {
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	/* display latency trace as call graph */
-	{ TRACER_OPT(irqsoff-graph, TRACE_IRQSOFF_GRAPH) },
+	{ TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) },
 #endif
 	{ } /* Empty entry */
 };
@@ -73,7 +73,7 @@ static struct tracer_flags tracer_flags = {
 	.opts = trace_opts,
 };
 
-#define is_graph() (tracer_flags.val & TRACE_IRQSOFF_GRAPH)
+#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH)
 
 /*
  * Sequence count - we record it when starting a measurement and
@@ -133,7 +133,7 @@ static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
 {
 	int cpu;
 
-	if (!(bit & TRACE_IRQSOFF_GRAPH))
+	if (!(bit & TRACE_DISPLAY_GRAPH))
 		return -EINVAL;
 
 	if (!(is_graph() ^ set))
@@ -550,8 +550,8 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.reset		= irqsoff_tracer_reset,
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
-	.flags		= &tracer_flags,
 	.print_max	= 1,
+	.flags		= &tracer_flags,
 	.set_flag	= irqsoff_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_irqsoff,
@@ -583,9 +583,15 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
 	.print_max	= 1,
+	.flags		= &tracer_flags,
+	.set_flag	= irqsoff_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptoff,
 #endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.open           = irqsoff_trace_open,
+	.close          = irqsoff_trace_close,
+#endif
 };
 # define register_preemptoff(trace) register_tracer(&trace)
 #else
@@ -611,9 +617,15 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
 	.print_max	= 1,
+	.flags		= &tracer_flags,
+	.set_flag	= irqsoff_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptirqsoff,
 #endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.open           = irqsoff_trace_open,
+	.close          = irqsoff_trace_close,
+#endif
 };
 
 # define register_preemptirqsoff(trace) register_tracer(&trace)
-- 
1.6.6

[PATCH 4/4] tracing: raw output for graph tracer

[Jiri Olsa]

hi,

this patch adds raw trace output for graph tracer.

I have this one around for long time and it was quite handy
for investigating graph tracer issues.

wbr,
jirka


Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 kernel/trace/trace.c                 |    2 +-
 kernel/trace/trace_functions_graph.c |   69 ++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 032c57c..723fa93 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1900,7 +1900,7 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 	entry = iter->ent;
 
 	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
-		if (!trace_seq_printf(s, "%d %d %llu ",
+		if (!trace_seq_printf(s, " %6d %3d %20llu ",
 				      entry->pid, iter->cpu, iter->ts))
 			goto partial;
 	}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index eca09b3..023e0be 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -1033,6 +1033,66 @@ print_graph_function(struct trace_iterator *iter, int flags)
 	return TRACE_TYPE_HANDLED;
 }
 
+static enum print_line_t
+print_graph_raw(struct trace_iterator *iter, int flags)
+{
+	struct trace_entry *entry = iter->ent;
+	struct trace_seq *s = &iter->seq;
+	int ret = 0;
+	int depth;
+	void *func;
+	char *io;
+
+	switch (entry->type) {
+	case TRACE_GRAPH_ENT: {
+		struct ftrace_graph_ent_entry *field;
+		trace_assign_type(field, entry);
+		depth = field->graph_ent.depth;
+		func = (void *) field->graph_ent.func;
+		io = "-->";
+		break;
+	}
+	case TRACE_GRAPH_RET: {
+		struct ftrace_graph_ret_entry *field;
+		trace_assign_type(field, entry);
+		depth = field->ret.depth;
+		func = (void *) field->ret.func;
+		io = "<--";
+		break;
+	}
+	default:
+		return print_graph_comment(s, entry, iter);
+	}
+
+	ret = trace_seq_printf(s, "%s%6d %6d %6d %4d %7d %20p %4s %ps\n",
+		trace_flags & TRACE_ITER_CONTEXT_INFO ? "" : " ",
+		depth,
+		entry->lock_depth,
+		entry->flags,
+		entry->preempt_count,
+		entry->pid,
+		entry,
+		io,
+		func);
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static void print_graph_raw_header(struct seq_file *s)
+{
+	if (trace_flags & TRACE_ITER_CONTEXT_INFO)
+		seq_printf(s, "#%6s %3s %20s ", "pid", "cpu", "duration");
+	else
+		seq_printf(s, "#");
+
+	seq_printf(s, "%6s %6s %6s %4s %7s %20s %4s %s\n",
+		"depth", "ldepth", "flags", "pc", "pid",
+		"entry", "i/o", "function");
+}
+
 static void print_lat_header(struct seq_file *s)
 {
 	static const char spaces[] = "                "	/* 16 spaces */
@@ -1059,6 +1119,11 @@ void print_graph_headers(struct seq_file *s)
 {
 	int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
 
+	if (trace_flags & TRACE_ITER_RAW) {
+		print_graph_raw_header(s);
+		return;
+	}
+
 	if (lat)
 		print_lat_header(s);
 
@@ -1074,6 +1139,7 @@ void print_graph_headers(struct seq_file *s)
 		seq_printf(s, "|||||");
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
 		seq_printf(s, "  DURATION   ");
+
 	seq_printf(s, "               FUNCTION CALLS\n");
 
 	/* 2nd line */
@@ -1136,14 +1202,17 @@ void graph_trace_close(struct trace_iterator *iter)
 	}
 }
 
+
 static struct trace_event graph_trace_entry_event = {
 	.type		= TRACE_GRAPH_ENT,
 	.trace		= print_graph_function,
+	.raw		= print_graph_raw,
 };
 
 static struct trace_event graph_trace_ret_event = {
 	.type		= TRACE_GRAPH_RET,
 	.trace		= print_graph_function,
+	.raw		= print_graph_raw,
 };
 
 static struct tracer graph_trace __read_mostly = {
-- 
1.6.6

Re: [PATCH 0/4] tracing: function graph output for preempt/irqs-off tracers

[Jiri Olsa]

hi,
any feedback?

thanks,
jirka

On Mon, Feb 22, 2010 at 01:56:58PM +0100, Jiri Olsa wrote:
> hi,
> 
> I'm sending reworked version of the graph output support for
> preemptirqsoff/preemptoff/irqsoff tracers.
> 
> I made the graph output as an output event, so it could be shared
> within tracers - patch 1/4.
> 
> I also added raw trace output for graph tracer. I have this one around
> for long time and it was quite handy for investigating graph tracer issues.
> (patch 4/4)
> 
> 
> attached patches:
> - 1/4 adding ftrace events for graph tracer
> - 2/4 graph output support for irqsoff tracer
> - 3/4 graph output support for preemptirqsoff/preemptoff tracers
> - 4/4 raw output for graph tracer
> 
> wbr,
> jirka
> ---
>  kernel/trace/trace.c                 |    2 +-
>  kernel/trace/trace.h                 |   11 ++-
>  kernel/trace/trace_functions_graph.c |  117 +++++++++++++++++++----
>  kernel/trace/trace_irqsoff.c         |  174 ++++++++++++++++++++++++++++++++--
>  4 files changed, 277 insertions(+), 27 deletions(-)
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 0/4] tracing: function graph output for preempt/irqs-off tracers

[Steven Rostedt]

On Mon, 2010-03-08 at 08:07 +0100, Jiri Olsa wrote:
> hi,
> any feedback?

Ah, I forgot about this patch set. I'll take a look at it today.

Thanks,

-- Steve

> 
> thanks,
> jirka
> 
> On Mon, Feb 22, 2010 at 01:56:58PM +0100, Jiri Olsa wrote:
> > hi,
> > 
> > I'm sending reworked version of the graph output support for
> > preemptirqsoff/preemptoff/irqsoff tracers.
> > 
> > I made the graph output as an output event, so it could be shared
> > within tracers - patch 1/4.
> > 
> > I also added raw trace output for graph tracer. I have this one around
> > for long time and it was quite handy for investigating graph tracer issues.
> > (patch 4/4)
> > 
> > 
> > attached patches:
> > - 1/4 adding ftrace events for graph tracer
> > - 2/4 graph output support for irqsoff tracer
> > - 3/4 graph output support for preemptirqsoff/preemptoff tracers
> > - 4/4 raw output for graph tracer
> > 
> > wbr,
> > jirka
> > ---
> >  kernel/trace/trace.c                 |    2 +-
> >  kernel/trace/trace.h                 |   11 ++-
> >  kernel/trace/trace_functions_graph.c |  117 +++++++++++++++++++----
> >  kernel/trace/trace_irqsoff.c         |  174 ++++++++++++++++++++++++++++++++--
> >  4 files changed, 277 insertions(+), 27 deletions(-)
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 1/4] tracing: adding ftrace events for graph tracer

[Steven Rostedt]

On Mon, 2010-02-22 at 13:56 +0100, Jiri Olsa wrote:
> hi,
> 
> this patch adds ftrace events for graph tracer, so the graph output
> could be shared within other tracers.
> 

Sorry but NAK to this,

What use to be:

 2) + 25.633 us   |                        }
 3) ! 252.132 us  |              } /* do_softirq */
 2) ! 898.211 us  |                      } /* rcu_process_callbacks */
 2)               |                      /* softirq_exit: vec=9 [action=RCU] */
 3)   5.534 us    |              rcu_irq_exit();
 2)   6.405 us    |                      preempt_schedule();
 3)   5.221 us    |              idle_cpu();
 2)   6.014 us    |                      rcu_bh_qs();
 3) ! 289.729 us  |            } /* irq_exit */
 2)               |                      /* softirq_entry: vec=1 [action=TIMER] */
 3) ! 860.416 us  |          } /* smp_apic_timer_interrupt */
 3)   <========== |
 2)   5.785 us    |                      preempt_schedule();


Is now:

      gdmgreeter-3382  [002]   119.609346:  2) + 25.633 us   |                        }
           pcscd-2849  [003]   119.609352:  3) ! 252.132 us  |              } /* do_softirq */
      gdmgreeter-3382  [002]   119.609353:  2) ! 898.211 us  |                      } /* rcu_process_callbacks */
      gdmgreeter-3382  [002]   119.609357: softirq_exit: vec=9 [action=RCU]
           pcscd-2849  [003]   119.609360:  3)   5.534 us    |              rcu_irq_exit();
      gdmgreeter-3382  [002]   119.609363:  2)   6.405 us    |                      preempt_schedule();
           pcscd-2849  [003]   119.609370:  3)   5.221 us    |              idle_cpu();
      gdmgreeter-3382  [002]   119.609376:  2)   6.014 us    |                      rcu_bh_qs();
           pcscd-2849  [003]   119.609383:  3) ! 289.729 us  |            } /* irq_exit */
      gdmgreeter-3382  [002]   119.609387: softirq_entry: vec=1 [action=TIMER]
           pcscd-2849  [003]   119.609389:  3) ! 860.416 us  |          } /* smp_apic_timer_interrupt */
 3)   <========== |
      gdmgreeter-3382  [002]   119.609393:  2)   5.785 us    |                      preempt_schedule();


Keep the function graph output as is. You can still add the event
callbacks but do not remove the print_line of the function graph tracer.
That simply breaks what we worked hard to format nicely.

-- Steve


> 
> Signed-off-by: Jiri Olsa <jolsa@redhat.com>
> ---
>  kernel/trace/trace.h                 |    3 ++-
>  kernel/trace/trace_functions_graph.c |   25 ++++++++++++++++++++++---
>  2 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index b477fce..1feda87 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -490,7 +490,8 @@ extern int trace_clock_id;
>  
>  /* Standard output formatting function used for function return traces */
>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> -extern enum print_line_t print_graph_function(struct trace_iterator *iter);
> +extern enum print_line_t print_graph_function(struct trace_iterator *iter,
> +					      int flags);
>  extern enum print_line_t
>  trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
>  
> diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
> index 616b135..41cec17 100644
> --- a/kernel/trace/trace_functions_graph.c
> +++ b/kernel/trace/trace_functions_graph.c
> @@ -38,7 +38,7 @@ struct fgraph_data {
>  #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
> +#define TRACE_GRAPH_PRINT_ABS_TIME	0x20
>  
>  static struct tracer_opt trace_opts[] = {
>  	/* Display overruns? (for self-debug purpose) */
> @@ -985,7 +985,7 @@ print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
>  
> 
>  enum print_line_t
> -print_graph_function(struct trace_iterator *iter)
> +print_graph_function(struct trace_iterator *iter, int flags)
>  {
>  	struct ftrace_graph_ent_entry *field;
>  	struct fgraph_data *data = iter->private;
> @@ -1143,6 +1143,16 @@ static void graph_trace_close(struct trace_iterator *iter)
>  	}
>  }
>  
> +static struct trace_event graph_trace_entry_event = {
> +	.type		= TRACE_GRAPH_ENT,
> +	.trace		= print_graph_function,
> +};
> +
> +static struct trace_event graph_trace_ret_event = {
> +	.type		= TRACE_GRAPH_RET,
> +	.trace		= print_graph_function,
> +};
> +
>  static struct tracer graph_trace __read_mostly = {
>  	.name		= "function_graph",
>  	.open		= graph_trace_open,
> @@ -1152,7 +1162,6 @@ static struct tracer graph_trace __read_mostly = {
>  	.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
> @@ -1164,6 +1173,16 @@ 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);
>  }
>  

Re: [PATCH 1/4] tracing: adding ftrace events for graph tracer

[Jiri Olsa]

On Mon, Mar 08, 2010 at 02:29:46PM -0500, Steven Rostedt wrote:
> On Mon, 2010-02-22 at 13:56 +0100, Jiri Olsa wrote:
> > hi,
> > 
> > this patch adds ftrace events for graph tracer, so the graph output
> > could be shared within other tracers.
> > 
> 
> Sorry but NAK to this,

right, I haven't realized this to be a problem,
I'll send new version shortly

wbr,
jirka

> 
> What use to be:
> 
>  2) + 25.633 us   |                        }
>  3) ! 252.132 us  |              } /* do_softirq */
>  2) ! 898.211 us  |                      } /* rcu_process_callbacks */
>  2)               |                      /* softirq_exit: vec=9 [action=RCU] */
>  3)   5.534 us    |              rcu_irq_exit();
>  2)   6.405 us    |                      preempt_schedule();
>  3)   5.221 us    |              idle_cpu();
>  2)   6.014 us    |                      rcu_bh_qs();
>  3) ! 289.729 us  |            } /* irq_exit */
>  2)               |                      /* softirq_entry: vec=1 [action=TIMER] */
>  3) ! 860.416 us  |          } /* smp_apic_timer_interrupt */
>  3)   <========== |
>  2)   5.785 us    |                      preempt_schedule();
> 
> 
> Is now:
> 
>       gdmgreeter-3382  [002]   119.609346:  2) + 25.633 us   |                        }
>            pcscd-2849  [003]   119.609352:  3) ! 252.132 us  |              } /* do_softirq */
>       gdmgreeter-3382  [002]   119.609353:  2) ! 898.211 us  |                      } /* rcu_process_callbacks */
>       gdmgreeter-3382  [002]   119.609357: softirq_exit: vec=9 [action=RCU]
>            pcscd-2849  [003]   119.609360:  3)   5.534 us    |              rcu_irq_exit();
>       gdmgreeter-3382  [002]   119.609363:  2)   6.405 us    |                      preempt_schedule();
>            pcscd-2849  [003]   119.609370:  3)   5.221 us    |              idle_cpu();
>       gdmgreeter-3382  [002]   119.609376:  2)   6.014 us    |                      rcu_bh_qs();
>            pcscd-2849  [003]   119.609383:  3) ! 289.729 us  |            } /* irq_exit */
>       gdmgreeter-3382  [002]   119.609387: softirq_entry: vec=1 [action=TIMER]
>            pcscd-2849  [003]   119.609389:  3) ! 860.416 us  |          } /* smp_apic_timer_interrupt */
>  3)   <========== |
>       gdmgreeter-3382  [002]   119.609393:  2)   5.785 us    |                      preempt_schedule();
> 
> 
> Keep the function graph output as is. You can still add the event
> callbacks but do not remove the print_line of the function graph tracer.
> That simply breaks what we worked hard to format nicely.
> 
> -- Steve
> 
> 
> > 
> > Signed-off-by: Jiri Olsa <jolsa@redhat.com>
> > ---
> >  kernel/trace/trace.h                 |    3 ++-
> >  kernel/trace/trace_functions_graph.c |   25 ++++++++++++++++++++++---
> >  2 files changed, 24 insertions(+), 4 deletions(-)
> > 
> > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > index b477fce..1feda87 100644
> > --- a/kernel/trace/trace.h
> > +++ b/kernel/trace/trace.h
> > @@ -490,7 +490,8 @@ extern int trace_clock_id;
> >  
> >  /* Standard output formatting function used for function return traces */
> >  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> > -extern enum print_line_t print_graph_function(struct trace_iterator *iter);
> > +extern enum print_line_t print_graph_function(struct trace_iterator *iter,
> > +					      int flags);
> >  extern enum print_line_t
> >  trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
> >  
> > diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
> > index 616b135..41cec17 100644
> > --- a/kernel/trace/trace_functions_graph.c
> > +++ b/kernel/trace/trace_functions_graph.c
> > @@ -38,7 +38,7 @@ struct fgraph_data {
> >  #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
> > +#define TRACE_GRAPH_PRINT_ABS_TIME	0x20
> >  
> >  static struct tracer_opt trace_opts[] = {
> >  	/* Display overruns? (for self-debug purpose) */
> > @@ -985,7 +985,7 @@ print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
> >  
> > 
> >  enum print_line_t
> > -print_graph_function(struct trace_iterator *iter)
> > +print_graph_function(struct trace_iterator *iter, int flags)
> >  {
> >  	struct ftrace_graph_ent_entry *field;
> >  	struct fgraph_data *data = iter->private;
> > @@ -1143,6 +1143,16 @@ static void graph_trace_close(struct trace_iterator *iter)
> >  	}
> >  }
> >  
> > +static struct trace_event graph_trace_entry_event = {
> > +	.type		= TRACE_GRAPH_ENT,
> > +	.trace		= print_graph_function,
> > +};
> > +
> > +static struct trace_event graph_trace_ret_event = {
> > +	.type		= TRACE_GRAPH_RET,
> > +	.trace		= print_graph_function,
> > +};
> > +
> >  static struct tracer graph_trace __read_mostly = {
> >  	.name		= "function_graph",
> >  	.open		= graph_trace_open,
> > @@ -1152,7 +1162,6 @@ static struct tracer graph_trace __read_mostly = {
> >  	.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
> > @@ -1164,6 +1173,16 @@ 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);
> >  }
> >  
>