About Ftrace
-------------
Ftrace is an internal tracer designed to find what is going on inside the kernel. It can be used
-for debugging or analyzing latencies and performance issues that take place outside of user-space.
-Although ftrace is typically considered the function tracer, it is really a frame work of several
-assorted tracing utilities.
+for debugging or analyzing latencies and performance related issues that take place outside of
+user-space. Although ftrace is typically considered the function tracer, it is really a frame
+work of several assorted tracing utilities.
One of the most common uses of ftrace is the event tracing.
+-----------------------------+-----------------------------------------------+
| | - Ftrace aids in debugging the KVMFORNFV |
| Danube | 4.4-linux-kernel level issues |
-| | - Option to diable if not required |
+| | - Option to disable if not required |
+-----------------------------+-----------------------------------------------+
[tracing]# echo 1 > tracing_on;
-===================
Ftrace in KVMFORNFV
-===================
-Ftrace is part of KVMFORNFV D-Release. Kvmfornfv currently uses 4.4-linux-Kernel as part of
-deployment and runs cyclictest for testing purpose generating latency values (max, min, avg values).
+-------------------
+Ftrace is part of KVMFORNFV D-Release. KVMFORNFV built 4.4-linux-Kernel will be tested by
+executing cyclictest and analyzing the results/latency values (max, min, avg) generated.
Ftrace (or) function tracer is a stable kernel inbuilt debugging tool which tests kernel in real
time and outputs a log as part of the code. These output logs are useful in following ways.
- Kernel Debugging.
- - Helps in Kernel code Optimization and
- - Can be used to better understand the kernel Level code flow
- - Log generation for each test run if enabled
- - Choice of Disabling and Enabling
+ - Helps in Kernel code optimization and
+ - Can be used to better understand the kernel level code flow
Ftrace logs for KVMFORNFV can be found `here`_:
Enabling Ftrace in KVMFORNFV
----------------------------
-The enable_trace.sh script is triggered by changing ftrace_enable value in test_kvmfornfv.sh script which is zero by default. Change as below to enable Ftrace and trigger the script,
+The enable_trace.sh script is triggered by changing ftrace_enable value in test_kvmfornfv.sh
+script to 1 (which is zero by default). Change as below to enable Ftrace.
.. code:: bash
Details of enable_trace script
------------------------------
-- CPU Coremask is calculated using getcpumask()
+- CPU coremask is calculated using getcpumask()
- All the required events are enabled by,
echoing "1" to $TRACEDIR/events/event_name/enable file
- Once tracing is diabled, disable_trace.sh script is triggered.
-Details of Disable_trace Script
+Details of disable_trace Script
-------------------------------
In disable trace script the following are done:
-- The trace file is copied and moved to /tmp folfer based on timestamp.
+- The trace file is copied and moved to /tmp folder based on timestamp
- The current tracer file is set to ``nop``
- The set_event file is cleared i.e., all the enabled events are disabled
-- Kernel Ftarcer is diabled/unmounted
+- Kernel Ftrace is disabled/unmounted
Publishing Ftrace logs:
-----------------------
-The generated trace log is pushed to `artifacts`_ of Kvmfornfv project by releng team, which is done by a script in JJB of releng. The `trigger`_ in the script is.,
+The generated trace log is pushed to `artifacts`_ by kvmfornfv-upload-artifact.sh
+script available in releng which will be triggered as a part of kvmfornfv daily job.
+The `trigger`_ in the script is.,
.. code:: bash
.. _artifacts: https://artifacts.opnfv.org/
.. _trigger: https://gerrit.opnfv.org/gerrit/gitweb?p=releng.git;a=blob;f=jjb/kvmfornfv/kvmfornfv-upload-artifact.sh;h=56fb4f9c18a83c689a916dc6c85f9e3ddf2479b2;hb=HEAD#l53
-
-
-.. include:: pcm_utility.userguide.rst
Code Review / kvmfornfv.git / blobdiff