From: John Levon <movement@us...> - 2003-03-20 21:54:00
Update of /cvsroot/oprofile/oprofile/doc
In directory sc8-pr-cvs1:/tmp/cvs-serv12678/doc
doc some 2.5 module stuff
RCS file: /cvsroot/oprofile/oprofile/doc/oprofile.xml,v
retrieving revision 1.67
retrieving revision 1.68
diff -u -d -r1.67 -r1.68
--- oprofile.xml 17 Mar 2003 14:36:28 -0000 1.67
+++ oprofile.xml 20 Mar 2003 21:53:53 -0000 1.68
@@ -1518,6 +1518,32 @@
within the kernel <function>do_exit()</function> routine cannot be profiled.
+<title>Profiling kernel modules</title>
+OProfile profiles kernel modules by default. However, there are a couple of problems
+you may have when trying to get results. First, you may have booted via an initrd;
+this means that the actual path for the module binaries cannot be determined automatically.
+To get around this, you can use the <option>-p</option> option to the profiling tools
+to specify where to look for the kernel modules.
+In 2.5, the information on where kernel module binaries are located has been removed.
+This means OProfile needs guiding with the <option>-p</option> option to find your
+modules. Normally, you can just use your standard module top-level directory for this.
+Note that due to this problem, OProfile cannot check that the modification times match;
+it is your responsibility to make sure you do not modify a binary after a profile
+has been created.
+If you have run <command>insmod</command> or <command>modprobe</command> to insert a module
+in a particular directory, it is important that you specify this directory with the
+<option>-p</option> option first, so that it over-rides an older module binary that might
+exist in other directories you've specified with <option>-p</option>. It is up to you
+to make sure that these values are correct: 2.5 kernels simply do not provide enough
+information for OProfile to get this information.