tracing: Add disable_on_free option
Add a trace option to disable tracing on free. When this option is
set, a write into the free_buffer file will not only shrink the
ring buffer down to zero, but it will also disable tracing.
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9c557ae..42fdf3a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -425,6 +425,7 @@
"graph-time",
"record-cmd",
"overwrite",
+ "disable_on_free",
NULL
};
@@ -3518,8 +3519,9 @@
static int
tracing_free_buffer_release(struct inode *inode, struct file *filp)
{
- /* disable tracing */
- tracing_off();
+ /* disable tracing ? */
+ if (trace_flags & TRACE_ITER_STOP_ON_FREE)
+ tracing_off();
/* resize the ring buffer to 0 */
tracing_resize_ring_buffer(0);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 229f859..742f545 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -609,6 +609,7 @@
TRACE_ITER_GRAPH_TIME = 0x80000,
TRACE_ITER_RECORD_CMD = 0x100000,
TRACE_ITER_OVERWRITE = 0x200000,
+ TRACE_ITER_STOP_ON_FREE = 0x400000,
};
/*