tracing: Add graph output support for irqsoff tracer

Add function graph output to irqsoff tracer.

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

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1270227683-14631-4-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Jiri Olsa
2010-04-02 19:01:22 +02:00
committed by Steven Rostedt
parent d7a8d9e907
commit 62b915f106
5 changed files with 324 additions and 33 deletions

View File

@@ -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_DISPLAY_GRAPH 1
static struct tracer_opt trace_opts[] = {
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* display latency trace as call graph */
{ TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) },
#endif
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
.val = 0,
.opts = trace_opts,
};
#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH)
/*
* Sequence count - we record it when starting a measurement and
* skip the latency if the sequence has changed - some other section
@@ -108,6 +128,202 @@ 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_DISPLAY_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);
}
#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
TRACE_GRAPH_PRINT_PROC)
static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
{
u32 flags = GRAPH_TRACER_FLAGS;
if (trace_flags & TRACE_ITER_LATENCY_FMT)
flags |= TRACE_GRAPH_PRINT_DURATION;
else
flags |= TRACE_GRAPH_PRINT_ABS_TIME;
/*
* In graph mode call the graph tracer output function,
* otherwise go with the TRACE_FN event handler
*/
if (is_graph())
return print_graph_function_flags(iter, flags);
return TRACE_TYPE_UNHANDLED;
}
static void irqsoff_print_header(struct seq_file *s)
{
if (is_graph()) {
struct trace_iterator *iter = s->private;
u32 flags = GRAPH_TRACER_FLAGS;
if (trace_flags & TRACE_ITER_LATENCY_FMT) {
/* print nothing if the buffers are empty */
if (trace_empty(iter))
return;
print_trace_header(s, iter);
flags |= TRACE_GRAPH_PRINT_DURATION;
} else
flags |= TRACE_GRAPH_PRINT_ABS_TIME;
print_graph_headers_flags(s, flags);
} else
trace_default_header(s);
}
static void
trace_graph_function(struct trace_array *tr,
unsigned long ip, unsigned long flags, int pc)
{
u64 time = trace_clock_local();
struct ftrace_graph_ent ent = {
.func = ip,
.depth = 0,
};
struct ftrace_graph_ret ret = {
.func = ip,
.depth = 0,
.calltime = time,
.rettime = time,
};
__trace_graph_entry(tr, &ent, flags, pc);
__trace_graph_return(tr, &ret, flags, pc);
}
static void
__trace_function(struct trace_array *tr,
unsigned long ip, unsigned long parent_ip,
unsigned long flags, int pc)
{
if (!is_graph())
trace_function(tr, ip, parent_ip, flags, pc);
else {
trace_graph_function(tr, parent_ip, flags, pc);
trace_graph_function(tr, ip, flags, pc);
}
}
#else
#define __trace_function trace_function
static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
{
return -EINVAL;
}
static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
{
return -1;
}
static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
}
static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
static void irqsoff_print_header(struct seq_file *s) { }
static void irqsoff_trace_open(struct trace_iterator *iter) { }
static void irqsoff_trace_close(struct trace_iterator *iter) { }
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/*
* Should this new latency be reported/recorded?
*/
@@ -150,7 +366,7 @@ check_critical_timing(struct trace_array *tr,
if (!report_latency(delta))
goto out_unlock;
trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
__trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
/* Skip 5 functions to get to the irq/preempt enable function */
__trace_stack(tr, flags, 5, pc);
@@ -172,7 +388,7 @@ out_unlock:
out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
__trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
}
static inline void
@@ -204,7 +420,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
local_save_flags(flags);
trace_function(tr, ip, parent_ip, flags, preempt_count());
__trace_function(tr, ip, parent_ip, flags, preempt_count());
per_cpu(tracing_cpu, cpu) = 1;
@@ -238,7 +454,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
atomic_inc(&data->disabled);
local_save_flags(flags);
trace_function(tr, ip, parent_ip, flags, preempt_count());
__trace_function(tr, ip, parent_ip, flags, preempt_count());
check_critical_timing(tr, data, parent_ip ? : ip, cpu);
data->critical_start = 0;
atomic_dec(&data->disabled);
@@ -347,19 +563,32 @@ 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);
else
ret = register_ftrace_graph(&irqsoff_graph_return,
&irqsoff_graph_entry);
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);
else
unregister_ftrace_graph();
}
static void __irqsoff_tracer_init(struct trace_array *tr)
@@ -372,12 +601,14 @@ 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;
@@ -409,9 +640,15 @@ static struct tracer irqsoff_tracer __read_mostly =
.start = irqsoff_tracer_start,
.stop = irqsoff_tracer_stop,
.print_max = 1,
.print_header = irqsoff_print_header,
.print_line = irqsoff_print_line,
.flags = &tracer_flags,
.set_flag = irqsoff_set_flag,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_irqsoff,
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
};
# define register_irqsoff(trace) register_tracer(&trace)
#else
@@ -435,9 +672,15 @@ static struct tracer preemptoff_tracer __read_mostly =
.start = irqsoff_tracer_start,
.stop = irqsoff_tracer_stop,
.print_max = 1,
.print_header = irqsoff_print_header,
.print_line = irqsoff_print_line,
.flags = &tracer_flags,
.set_flag = irqsoff_set_flag,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_preemptoff,
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
};
# define register_preemptoff(trace) register_tracer(&trace)
#else
@@ -463,9 +706,15 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
.start = irqsoff_tracer_start,
.stop = irqsoff_tracer_stop,
.print_max = 1,
.print_header = irqsoff_print_header,
.print_line = irqsoff_print_line,
.flags = &tracer_flags,
.set_flag = irqsoff_set_flag,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_preemptirqsoff,
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
};
# define register_preemptirqsoff(trace) register_tracer(&trace)