tracing: disable update max tracer while reading trace

When reading the tracer from the trace file, updating the max latency
may corrupt the output. This patch disables the tracing of the max
latency while reading the trace file.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2009-08-31 22:32:27 -04:00 committed by Steven Rostedt
parent 8248ac052d
commit b8de7bd168
1 changed files with 9 additions and 3 deletions

View File

@ -263,6 +263,9 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
TRACE_ITER_GRAPH_TIME;
static int trace_stop_count;
static DEFINE_SPINLOCK(tracing_start_lock);
/**
* trace_wake_up - wake up tasks waiting for trace input
*
@ -442,6 +445,9 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
struct ring_buffer *buf = tr->buffer;
if (trace_stop_count)
return;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
@ -469,6 +475,9 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
int ret;
if (trace_stop_count)
return;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
@ -685,9 +694,6 @@ static void trace_init_cmdlines(void)
cmdline_idx = 0;
}
static int trace_stop_count;
static DEFINE_SPINLOCK(tracing_start_lock);
/**
* ftrace_off_permanent - disable all ftrace code permanently
*