Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH] tracing/latency: Fix header output for latency tracers | Date | Tue, 13 Sep 2011 16:03:34 +0200 |
| |
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 # cat-1163 0d..4 1us : 1163:120:R + [000] 6: 0:R migration/0 cat-1163 0d..4 2us+: ttwu_do_activate.clone.1 <-try_to_wake_up cat-1163 0d..3 4us : __schedule <-preempt_schedule cat-1163 0d..3 4us : 1163:120:R ==> [000] 6: 0:R migration/0
* The fixed output is:
# tracer: wakeup # # wakeup latency trace v1.1.5 on 3.1.0-rc4-tip+ # -------------------------------------------------------------------- # latency: 91 us, #4/4, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2) # ----------------- # | task: watchdog/0-7 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # <idle>-0 0d.h5 1us : 0:120:R + [000] 7: 0:R watchdog/0 <idle>-0 0d.h5 2us+: ttwu_do_activate.clone.1 <-try_to_wake_up <idle>-0 0d..3 17us : __schedule <-schedule <idle>-0 0d..3 17us : 0:120:R ==> [000] 7: 0:R watchdog/0
* There's slightly different output (for wakeup_rt tracer) when function tracer is enabled, currently:
# tracer: wakeup_rt # cat-1168 1d..4 0us : 1168:120:R + [001] 8: 0:R migration/1 cat-1168 1d..4 1us : ttwu_do_activate.clone.1 <-try_to_wake_up cat-1168 1d..3 1us : check_preempt_curr <-ttwu_do_wakeup ...
* After the fix:
# tracer: wakeup_rt # # wakeup_rt latency trace v1.1.5 on 3.1.0-rc4-tip+ # -------------------------------------------------------------------- # latency: 209 us, #113/113, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2) # ----------------- # | task: watchdog/0-7 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / delay # cmd pid ||||| time | caller # \ / ||||| \ | / cat-1168 1d..4 0us : 1168:120:R + [001] 8: 0:R migration/1 cat-1168 1d..4 1us : ttwu_do_activate.clone.1 <-try_to_wake_up cat-1168 1d..3 1us : check_preempt_curr <-ttwu_do_wakeup ...
Signed-off-by: Jiri Olsa <jolsa@redhat.com> --- kernel/trace/trace.c | 12 ++++++++++++ kernel/trace/trace.h | 1 + kernel/trace/trace_irqsoff.c | 13 ++++++++++++- kernel/trace/trace_sched_wakeup.c | 13 ++++++++++++- 4 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e5df02c..7086345 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2139,6 +2139,18 @@ 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); +} + 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 616846b..db40865 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 667aa8c..2a0aee6 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 */ /* -- 1.7.1
| |