While the Oracle Linux kernel can dynamically load and unload kernel
modules, for fbt
probes, the
fbt
kernel module must be loaded to support
the instrumentation. For more information about loading kernel
modules, see the note in Section 1.1, “Getting Started With DTrace”. If
fbt
is not listed in
/etc/dtrace-modules
, or if the
dtrace -l command lists no
fbt
probes, use the following command:
# modprobe fbt
Conversely, you can unload the fbt
instrumentation with the following command:
# modprobe -r fbt
When the fbt
module is loaded, FBT
automatically provides probes to instrument all other loaded
modules, including any new modules that are dynamically loaded.
If a loaded module has no enabled FBT probes, the module might
be unloaded and the corresponding probes are destroyed as the
module is unloaded. If a loaded module has enabled FBT probes,
the module is considered busy and cannot be unloaded.