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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2020-03-17 22:32:31 +0100
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-03-27 21:39:01 +0100
commit06e0a548bad0f43a21e036db018e4dadb501ce8b (patch)
tree7587fb20e56bbb7fecf55fb4c9f0c6729b55f67d /Documentation/trace
parentring-buffer: Do not disable recording when there is an iterator (diff)
downloadlinux-06e0a548bad0f43a21e036db018e4dadb501ce8b.tar.xz
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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) <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/ftrace.rst6
1 files changed, 6 insertions, 0 deletions
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