Commit b8de7bd1 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

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: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 8248ac05

kernel/trace/trace.c

+9 −3
Original line number Diff line number Diff line
@@ -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

 *

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