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authorJiri Olsa <jolsa@redhat.com>2011-11-07 16:08:49 +0100
committerSteven Rostedt <rostedt@goodmis.org>2011-11-07 13:48:35 -0500
commit7e9a49ef542610609144d1afcd516dc3fafac4d6 (patch)
treea8b3748cbbb2ab61998d4c8e2f8c055e0edda104 /kernel/trace/trace.c
parentd4d34b981a5327eec956c6cb4cce397ce6f57279 (diff)
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 # <idle>-0 0d.h5 1us+: 0:120:R + [000] 7: 0:R watchdog/0 <idle>-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 # \ / ||||| \ | / <idle>-0 1d.h5 1us+: 0:120:R + [001] 12: 0:R watchdog/1 <idle>-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 <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b24a72d3500..b296186eb93 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;