CPU Profiling
If you built Ceph from source and compiled Ceph for use with oprofileyou 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 thevmlinux
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 thefollowing command:
- opreport -cal ./cmon | less
Important
After reviewing results, you should reset oprofile
beforerunning it again. Resetting oprofile
removes data from the sessiondirectory.
Resetting oprofile
To reset oprofile
, execute the following command:
- sudo opcontrol --reset
Important
You should reset oprofile
after analyzing data so thatyou do not commingle results from different tests.