From 06e0a548bad0f43a21e036db018e4dadb501ce8b Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Tue, 17 Mar 2020 17:32:31 -0400 Subject: tracing: Do not disable tracing when reading the trace file When opening the "trace" file, it is no longer necessary to disable tracing. Note, a new option is created called "pause-on-trace", when set, will cause the trace file to emulate its original behavior. Link: http://lkml.kernel.org/r/20200317213416.903351225@goodmis.org Signed-off-by: Steven Rostedt (VMware) --- Documentation/trace/ftrace.rst | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/trace/ftrace.rst') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 99a0890e20ec..c33950a35d65 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -1125,6 +1125,12 @@ Here are the available options: the trace displays additional information about the latency, as described in "Latency trace format". + pause-on-trace + When set, opening the trace file for read, will pause + writing to the ring buffer (as if tracing_on was set to zero). + This simulates the original behavior of the trace file. + When the file is closed, tracing will be enabled again. + record-cmd When any event or tracer is enabled, a hook is enabled in the sched_switch trace point to fill comm cache -- cgit v1.2.3-59-g8ed1b