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diff --git a/doc/rados/troubleshooting/cpu-profiling.rst b/doc/rados/troubleshooting/cpu-profiling.rst new file mode 100644 index 000000000..159f7998d --- /dev/null +++ b/doc/rados/troubleshooting/cpu-profiling.rst @@ -0,0 +1,67 @@ +=============== + CPU Profiling +=============== + +If you built Ceph from source and compiled Ceph for use with `oprofile`_ +you can profile Ceph's CPU usage. See `Installing Oprofile`_ for details. + + +Initializing oprofile +===================== + +The first time you use ``oprofile`` you need to initialize it. Locate the +``vmlinux`` image corresponding to the kernel you are now running. :: + + ls /boot + sudo opcontrol --init + sudo opcontrol --setup --vmlinux={path-to-image} --separate=library --callgraph=6 + + +Starting oprofile +================= + +To start ``oprofile`` execute the following command:: + + opcontrol --start + +Once you start ``oprofile``, you may run some tests with Ceph. + + +Stopping oprofile +================= + +To stop ``oprofile`` execute the following command:: + + opcontrol --stop + + +Retrieving oprofile Results +=========================== + +To retrieve the top ``cmon`` results, execute the following command:: + + opreport -gal ./cmon | less + + +To retrieve the top ``cmon`` results with call graphs attached, execute the +following command:: + + opreport -cal ./cmon | less + +.. important:: After reviewing results, you should reset ``oprofile`` before + running it again. Resetting ``oprofile`` removes data from the session + directory. + + +Resetting oprofile +================== + +To reset ``oprofile``, execute the following command:: + + sudo opcontrol --reset + +.. important:: You should reset ``oprofile`` after analyzing data so that + you do not commingle results from different tests. + +.. _oprofile: http://oprofile.sourceforge.net/about/ +.. _Installing Oprofile: ../../../dev/cpu-profiler |