Merge branch 'work.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux.git] / Documentation / trace / ftrace.rst

diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index f60079259669132e4745eede87b4bda933f3a6a5..e3060eedb22d7c6edaada02aeec723c300f37d33 100644 (file)
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -125,7 +125,8 @@ of ftrace. Here is a list of some of the key files:
 
        This file holds the output of the trace in a human
        readable format (described below). Note, tracing is temporarily
-       disabled while this file is being read (opened).
+       disabled when the file is open for reading. Once all readers
+       are closed, tracing is re-enabled.
 
   trace_pipe:
 
@@ -139,8 +140,9 @@ of ftrace. Here is a list of some of the key files:
        will not be read again with a sequential read. The
        "trace" file is static, and if the tracer is not
        adding more data, it will display the same
-       information every time it is read. This file will not
-       disable tracing while being read.
+       information every time it is read. Unlike the
+       "trace" file, opening this file for reading will not
+       temporarily disable tracing.
 
   trace_options:
 
@@ -3153,7 +3155,10 @@ different. The trace is live.
 
 
 Note, reading the trace_pipe file will block until more input is
-added.
+added. This is contrary to the trace file. If any process opened
+the trace file for reading, it will actually disable tracing and
+prevent new entries from being added. The trace_pipe file does
+not have this limitation.
 
 trace entries
 -------------