initial code repo

[stor4nfv.git] / src / 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