From 7e9a49ef542610609144d1afcd516dc3fafac4d6 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 7 Nov 2011 16:08:49 +0100 Subject: [PATCH] tracing/latency: Fix header output for latency tracers In case the the graph tracer (CONFIG_FUNCTION_GRAPH_TRACER) or even the function tracer (CONFIG_FUNCTION_TRACER) are not set, the latency tracers do not display proper latency header. The involved/fixed latency tracers are: wakeup_rt wakeup preemptirqsoff preemptoff irqsoff The patch adds proper handling of tracer configuration options for latency tracers, and displaying correct header info accordingly. * The current output (for wakeup tracer) with both graph and function tracers disabled is: # tracer: wakeup # -0 0d.h5 1us+: 0:120:R + [000] 7: 0:R watchdog/0 -0 0d.h5 3us+: ttwu_do_activate.clone.1 <-try_to_wake_up ... * The fixed output is: # tracer: wakeup # # wakeup latency trace v1.1.5 on 3.1.0-tip+ # -------------------------------------------------------------------- # latency: 55 us, #4/4, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2) # ----------------- # | task: migration/0-6 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / delay # cmd pid ||||| time | caller # \ / ||||| \ | / cat-1129 0d..4 1us : 1129:120:R + [000] 6: 0:R migration/0 cat-1129 0d..4 2us+: ttwu_do_activate.clone.1 <-try_to_wake_up * The current output (for wakeup tracer) with only function tracer enabled is: # tracer: wakeup # cat-1140 0d..4 1us+: 1140:120:R + [000] 6: 0:R migration/0 cat-1140 0d..4 2us : ttwu_do_activate.clone.1 <-try_to_wake_up * The fixed output is: # tracer: wakeup # # wakeup latency trace v1.1.5 on 3.1.0-tip+ # -------------------------------------------------------------------- # latency: 207 us, #109/109, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2) # ----------------- # | task: watchdog/1-12 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / delay # cmd pid ||||| time | caller # \ / ||||| \ | / -0 1d.h5 1us+: 0:120:R + [001] 12: 0:R watchdog/1 -0 1d.h5 3us : ttwu_do_activate.clone.1 <-try_to_wake_up Link: http://lkml.kernel.org/r/20111107150849.GE1807@m.brq.redhat.com Cc: Frederic Weisbecker Cc: Ingo Molnar Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 15 +++++++++++++++ kernel/trace/trace.h | 1 + kernel/trace/trace_irqsoff.c | 13 ++++++++++++- kernel/trace/trace_sched_wakeup.c | 13 ++++++++++++- 4 files changed, 40 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b24a72d..b296186 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2140,6 +2140,21 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) return print_trace_fmt(iter); } +void trace_latency_header(struct seq_file *m) +{ + struct trace_iterator *iter = m->private; + + /* print nothing if the buffers are empty */ + if (trace_empty(iter)) + return; + + if (iter->iter_flags & TRACE_FILE_LAT_FMT) + print_trace_header(m, iter); + + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_lat_help_header(m); +} + void trace_default_header(struct seq_file *m) { struct trace_iterator *iter = m->private; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 092e1f8..f8ec229 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -370,6 +370,7 @@ void trace_graph_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); +void trace_latency_header(struct seq_file *m); void trace_default_header(struct seq_file *m); void print_trace_header(struct seq_file *m, struct trace_iterator *iter); int trace_empty(struct trace_iterator *iter); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index a1a3359..a248c68 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -280,9 +280,20 @@ static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) } 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) { } + +#ifdef CONFIG_FUNCTION_TRACER +static void irqsoff_print_header(struct seq_file *s) +{ + trace_default_header(s); +} +#else +static void irqsoff_print_header(struct seq_file *s) +{ + trace_latency_header(s); +} +#endif /* CONFIG_FUNCTION_TRACER */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index e4a70c0..ff791ea 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -280,9 +280,20 @@ static enum print_line_t wakeup_print_line(struct trace_iterator *iter) } static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } -static void wakeup_print_header(struct seq_file *s) { } static void wakeup_trace_open(struct trace_iterator *iter) { } static void wakeup_trace_close(struct trace_iterator *iter) { } + +#ifdef CONFIG_FUNCTION_TRACER +static void wakeup_print_header(struct seq_file *s) +{ + trace_default_header(s); +} +#else +static void wakeup_print_header(struct seq_file *s) +{ + trace_latency_header(s); +} +#endif /* CONFIG_FUNCTION_TRACER */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* -- 2.7.4