update tracing doc for 2011.1

2 files changed, 24 insertions, 50 deletions

diff --git a/doc/tracing.html b/doc/tracing.html
index 6a54b62..3513bb4 100644
--- a/doc/tracing.html
+++ b/doc/tracing.html
@@ -11,9 +11,9 @@
 <!-- 
    Note: DO NOT EDIT THE HTML FILES!
 
-     The documentation is written using the markdown. The .html files are
+     The documentation is written using markdown. The .html files are
      generated from the .text files. If you want to update the
-     documentation you must edit the .text file and re-generate the
+     documentation you must edit the .txt file and re-generate the
      corresponding .html file by executing make.
 
      See 
@@ -27,7 +27,7 @@
     Note: PLEASE UPDATE THE CHANGE HISTORY AT THE END OF THE FILE WHEN YOU
           UPDATE THIS FILE.
 
-# The following line is picked up bye the gen_html script.
+# The following line is picked up by the gen_html script.
 TITLE=Tracing with LITMUS^RT
 -->
 
@@ -37,7 +37,7 @@ TITLE=Tracing with LITMUS^RT
 This document is part of the documentation of the <a href="../index.html">LITMUS<sup>RT</sup> project</a>.
 </div>
 
-<p>As of version 2010.2, there are three tracing mechanisms available in LITMUS<sup>RT</sup>:</p>
+<p>As of version 2011.1, there are three tracing mechanisms available in LITMUS<sup>RT</sup>:</p>
 
 <ol>
 <li><p><code>litmus_log</code>: This trace contains text messages (created with the <code>TRACE()</code>
@@ -49,28 +49,15 @@ macro, see <code>litmus.h</code>) that convey information useful for debugging.
 
 <h2>Accessing Trace Buffers</h2>
 
-<p><code>litmus_log</code> functionality is provided through the kernel's <code>misc</code> driver interface. As a result, <code>litmus_log</code> is automatically made available through <code>/dev/litmus/log</code> on systems with default udev rules.</p>
+<p><code>litmus_log</code> functionality is provided through the kernel's <code>misc</code> driver interface. The other two traces are exported to user space through standard character device drivers.</p>
 
-<p>The other two traces are exported to user space through standard character device drivers. The major numbers allocated by the drivers can be discovered by looking at <code>/proc/devices</code>. Usually, the major numbers are 252 and 253, respectively. The per-processor buffers are accessible via the minor numbers of the <code>sched_trace</code> driver.</p>
+<p>On systems with default udev rules, the devices are created in the <code>/dev/litmus/</code> directory:</p>
 
-<p>Thus, device files for <code>ft_trace</code> and <code>sched_trace</code> can be created with the following script.</p>
-
-<pre><code>#!/bin/bash
-
-FT_TRACE_MAJOR=`grep ft_trace /proc/devices | awk '{print $1}'`
-SCHED_TRACE_MAJOR=`grep sched_trace /proc/devices | awk '{print $1}'`
-
-mknod ft_trace   c $FT_TRACE_MAJOR   0
-
-NUM_PROCS=$((`grep 'processor' /proc/cpuinfo | wc -l` - 1))
-
-for P in `seq 0 $NUM_PROCS`
-do
-    mknod "sched_trace$P" c  $SCHED_TRACE_MAJOR  $P
-done
-</code></pre>
-
-<p>Alternatively, one can setup <code>udev</code> rules to create the devices on demand. This, however, is beyond the scope of this document.</p>
+<ul>
+<li>The <code>litmus_log</code> trace is exported as <code>/dev/litmus/log</code>.</li>
+<li>The <code>ft_trace</code> trace  is exported as <code>/dev/litmus/ft_trace0</code>.</li>
+<li>The <code>sched_trace</code> traces are exported as <code>/dev/litmus/sched_trace0</code>, <code>/dev/litmus/sched_trace1</code>,  etc. </li>
+</ul>
 
 <h2>Recording Debug Traces</h2>
 
@@ -185,7 +172,7 @@ Disabling 9 events.
 
 <p><strong>Hint</strong>: The dummy real-time task <code>rtspin</code> (distributed as part of the <code>liblitmus</code> package) may be useful when studying/testing the behavior of a scheduler plugin.</p>
 
-<p>Recorded scheduling traces can be analyzed with <a href="http://cs.unc.edu/~mollison/unit-trace">Unit-Trace</a>. Alternatively,  the user space library and tools package <code>liblitmus</code> contains the necessary headers to write <code>sched_trace</code> post-processing and analysis tools (see <code>include/sched_trace.h</code> and <code>src/sched_trace.c</code>).</p>
+<p>Recorded scheduling traces can be analyzed with <a href="http://cs.unc.edu/~mollison/unit-trace">Unit-Trace</a>.</p>
 
 <h2>Concluding Remarks</h2>
 
@@ -196,6 +183,7 @@ Disabling 9 events.
 <ul>
 <li>Initially written by <a href="http://www.cs.unc.edu/~bbb">Bjoern B. Brandenburg</a> (bbb at cs.unc.edu) on 12/09/2008.</li>
 <li>Updated for LITMUS<sup>RT</sup> version 2010.2 by <a href="http://www.cs.unc.edu/~mollison">Mac Mollison</a> (mollison at cs.unc.edu) on 11/08/2010.</li>
+<li>Updated for LITMUS<sup>RT</sup> version 2011.1  by <a href="http://www.cs.unc.edu/~bbb">Bjoern B. Brandenburg</a> (bbb at cs.unc.edu) on 01/12/2011. </li>
 </ul>
 <script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
 </script>
diff --git a/doc/tracing.txt b/doc/tracing.txt
index 80d14b0..106ec04 100644
--- a/doc/tracing.txt
+++ b/doc/tracing.txt
@@ -1,9 +1,9 @@
 <!-- 
    Note: DO NOT EDIT THE HTML FILES!
    
-         The documentation is written using the markdown. The .html files are
+         The documentation is written using markdown. The .html files are
          generated from the .text files. If you want to update the
-         documentation you must edit the .text file and re-generate the
+         documentation you must edit the .txt file and re-generate the
          corresponding .html file by executing make.
 
          See 
@@ -17,7 +17,7 @@
     Note: PLEASE UPDATE THE CHANGE HISTORY AT THE END OF THE FILE WHEN YOU
           UPDATE THIS FILE.
 
-# The following line is picked up bye the gen_html script.
+# The following line is picked up by the gen_html script.
 TITLE=Tracing with LITMUS^RT
 -->
 
@@ -28,7 +28,7 @@ Tracing with LITMUS<sup>RT</sup>
 This document is part of the documentation of the <a href="../index.html">LITMUS<sup>RT</sup> project</a>.
 </div>
 
-As of version 2010.2, there are three tracing mechanisms available in LITMUS<sup>RT</sup>:
+As of version 2011.1, there are three tracing mechanisms available in LITMUS<sup>RT</sup>:
 
 1. `litmus_log`: This trace contains text messages (created with the `TRACE()`
 macro, see `litmus.h`) that convey information useful for debugging. There is one global
@@ -41,27 +41,13 @@ macro, see `litmus.h`) that convey information useful for debugging. There is on
 Accessing Trace Buffers
 -----------------------
 
-`litmus_log` functionality is provided through the kernel's `misc` driver interface. As a result, `litmus_log` is automatically made available through `/dev/litmus/log` on systems with default udev rules.
+`litmus_log` functionality is provided through the kernel's `misc` driver interface. The other two traces are exported to user space through standard character device drivers.
 
-The other two traces are exported to user space through standard character device drivers. The major numbers allocated by the drivers can be discovered by looking at `/proc/devices`. Usually, the major numbers are 252 and 253, respectively. The per-processor buffers are accessible via the minor numbers of the `sched_trace` driver.
+On systems with default udev rules, the devices are created in the `/dev/litmus/` directory:
 
-Thus, device files for `ft_trace` and `sched_trace` can be created with the following script.
-
-    #!/bin/bash
-    
-    FT_TRACE_MAJOR=`grep ft_trace /proc/devices | awk '{print $1}'`
-    SCHED_TRACE_MAJOR=`grep sched_trace /proc/devices | awk '{print $1}'`
-    
-    mknod ft_trace   c $FT_TRACE_MAJOR   0
-    
-    NUM_PROCS=$((`grep 'processor' /proc/cpuinfo | wc -l` - 1))
-    
-    for P in `seq 0 $NUM_PROCS`
-    do
-                mknod "sched_trace$P" c  $SCHED_TRACE_MAJOR  $P
-    done
-
-Alternatively, one can setup `udev` rules to create the devices on demand. This, however, is beyond the scope of this document.
+- The `litmus_log` trace is exported as `/dev/litmus/log`.
+- The `ft_trace` trace  is exported as `/dev/litmus/ft_trace0`.
+- The `sched_trace` traces are exported as `/dev/litmus/sched_trace0`, `/dev/litmus/sched_trace1`,  etc. 
 
 Recording Debug Traces
 ----------------------
@@ -171,7 +157,7 @@ Note that `st_trace` may have to be modified to change the default `sched_trace`
 
 **Hint**: The dummy real-time task `rtspin` (distributed as part of the `liblitmus` package) may be useful when studying/testing the behavior of a scheduler plugin.
 
-Recorded scheduling traces can be analyzed with [Unit-Trace](http://cs.unc.edu/~mollison/unit-trace). Alternatively,  the user space library and tools package `liblitmus` contains the necessary headers to write `sched_trace` post-processing and analysis tools (see `include/sched_trace.h` and `src/sched_trace.c`).
+Recorded scheduling traces can be analyzed with [Unit-Trace](http://cs.unc.edu/~mollison/unit-trace).
 
 Concluding Remarks
 ------------------
@@ -182,4 +168,4 @@ Change History
 --------------
 - Initially written by <a href="http://www.cs.unc.edu/~bbb">Bjoern B. Brandenburg</a> (bbb at cs.unc.edu) on 12/09/2008.
 - Updated for LITMUS<sup>RT</sup> version 2010.2 by <a href="http://www.cs.unc.edu/~mollison">Mac Mollison</a> (mollison at cs.unc.edu) on 11/08/2010.
-
+- Updated for LITMUS<sup>RT</sup> version 2011.1  by <a href="http://www.cs.unc.edu/~bbb">Bjoern B. Brandenburg</a> (bbb at cs.unc.edu) on 01/12/2011.