diff options
| author | Carsten Emde <Carsten.Emde@osadl.org> | 2009-09-13 01:43:07 +0200 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-09-12 21:45:17 -0400 |
| commit | b5130b1e7d3717d03ab1916b198bf0d49fa0a619 (patch) | |
| tree | 67ee3282f6b6aa2e37864b938f67fd7e02b04394 /kernel/trace | |
| parent | 41dfba4367109b92d92ec6e059be6950497d932f (diff) | |
tracing: do not update tracing_max_latency when tracer is stopped
The state of the function pair tracing_stop()/tracing_start() is
correctly considered when tracer data are updated. However, the global
and externally accessible variable tracing_max_latency is always updated
- even when tracing is stopped.
The update should only occur, if tracing was not stopped.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_irqsoff.c | 6 | ||||
| -rw-r--r-- | kernel/trace/trace_sched_wakeup.c | 6 |
4 files changed, 14 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 45c3f0352d78..ef82a7fabf3b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -825,6 +825,11 @@ static void trace_init_cmdlines(void) cmdline_idx = 0; } +int is_tracing_stopped(void) +{ + return trace_stop_count; +} + /** * ftrace_off_permanent - disable all ftrace code permanently * diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 28247cecd955..4ad4e1ddcb9b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -461,6 +461,7 @@ void tracing_stop_sched_switch_record(void); void tracing_start_sched_switch_record(void); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); +int is_tracing_stopped(void); extern unsigned long nsecs_to_usecs(unsigned long nsecs); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 06f8ea9e4b9d..3aa7eaa2114c 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -157,8 +157,10 @@ check_critical_timing(struct trace_array *tr, data->critical_end = parent_ip; - tracing_max_latency = delta; - update_max_tr_single(tr, current, cpu); + if (likely(!is_tracing_stopped())) { + tracing_max_latency = delta; + update_max_tr_single(tr, current, cpu); + } max_sequence++; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 6e1529bc6172..26185d727676 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -162,8 +162,10 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, if (!report_latency(delta)) goto out_unlock; - tracing_max_latency = delta; - update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); + if (likely(!is_tracing_stopped())) { + tracing_max_latency = delta; + update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); + } out_unlock: __wakeup_reset(wakeup_trace); |