ceph/doc/rados/troubleshooting/cpu-profiling.rst

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===============
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