+ tunning+
diff --git a/docs/all/tunning.rst b/docs/all/tunning.rst
new file mode 100644
index 000000000..075bf0488
--- /dev/null
+++ b/
docs/all/tunning.rst@@ -0,0 +1,97 @@
+Low Latency Tunning Suggestion
+==============================
+
+The correct configuration is critical for improving the NFV performance/latency.
+Even working on the same codebase, configurations can cause wildly different
+performance/latency results.
+
+There are many combinations of configurations, from hardware configuration to
+Operating System configuration and application level configuration. And there
+is no one simple configuration that works for every case. To tune a specific
+scenario, it's important to know the behaviors of different configurations and
+their impact.
+
+Platform Configuration
+----------------------
+
+Some hardware features can be configured through firmware interface(like BIOS)
+but others may not be configurable (e.g. SMI on most platforms).
+
+* **Power management:**
+ Most power management related features save power at the
+ expensive of latency. These features include: Intel®Turbo Boost Technology,
+ Enhanced Intel®SpeedStep, Processor C state and P state. Normally they should
+ be disabled but, depending on the real-time application design and latency
+ requirements, there might be some features can be enabled if the impact on
+ deterministic execution of the workload is small.
+
+* **Hyper-Threading:**
+ The logic cores that share resource with other logic cores can introduce
+ latency so the recommendation is to disable this feature for realtime use
+ cases.
+
+* **Legacy USB Support/Port 60/64 Emulation:**
+ These features involve some emulation in firmware and can introduce random
+ latency. It is recommended that they are disabled.
+
+* **SMI (System Management Interrupt):**
+ SMI runs outside of the kernel code and can potentially cause
+ latency. It is a pity there is no simple way to disable it. Some vendors may
+ provide related switches in BIOS but most machines do not have this capability.
+
+Operating System Configuration
+------------------------------
+
+* **CPU isolation:**
+ To achieve deterministic latency, dedicated CPUs should be allocated for
+ realtime application. This can be achieved by isolating cpus from kernel
+ scheduler. Please refer to
+ http://lxr.free-electrons.com/source/Documentation/kernel-parameters.txt#L1608
+ for more information.
+
+* **Memory allocation:**
+ Memory shoud be reserved for realtime applications and usually hugepage should
+ be used to reduce page fauts/TLB misses.
+
+* **IRQ affinity:**
+ All the non-realtime IRQs should be affinitized to non realtime CPUs to
+ reduce the impact on realtime CPUs. Some OS distributions contain an irqbalance
+ deamon which balances the IRQs among all the cores dynamically. It should be
+ disabled as well.
+
+* **Device assignment for VM:**
+ If a device is used in a VM, then device passthrough is desirable. In this case,
+ the IOMMU should be enabled.
+
+* **Tickless:**
+ Frequent clock ticks cause latency. CONFIG_NOHZ_FULL should be enabled in the
+ linux kernel. With CONFIG_NOHZ_FULL, the physical CPU will trigger many fewer
+ clock tick interrupts(currently, 1 tick per second). This can reduce latency
+ because each host timer interrupt triggers a VM exit from guest to host which
+ causes performance/latency impacts.
+
+* **TSC:**
+ Mark TSC clock source as reliable. A TSC clock source that seems to be
+ unreliable causes the kernel to continuously enable the clock source watchdog
+ to check if TSC frequency is still correct. On recent Intel platforms with
+ Constant TSC/Invariant TSC/Synchronized TSC, the TSC is reliable so the
+ watchdog is useless but cause latency.
+
+* **Idle:**
+ The poll option forces a polling idle loop that can slightly improve the
+ performance of waking up an idle CPU.
+
+* **RCU_NOCB:**
+ RCU is a kernel synchronization mechanism. Refer to
+ http://lxr.free-electrons.com/source/Documentation/RCU/whatisRCU.txt for more
+ information. With RCU_NOCB, the impact from RCU to the VNF will be reduced.
+
+* **Disable the RT throttling:**
+ RT Throttling is a Linux kernel mechanism that
+ occurs when a process or thread uses 100% of the core, leaving no resources for
+ the Linux scheduler to execute the kernel/housekeeping tasks. RT Throttling
+ increases the latency so should be disabled.
+
+* **NUMA configuration:**
+ To achieve the best latency. CPU/Memory and device allocated for realtime
+ application/VM should be in the same NUMA node.
diff --git a/docs/etc/conf.py b/docs/etc/conf.py
deleted file mode 100644
index 006603516..000000000
--- a/
docs/etc/conf.py+++ /dev/null
@@ -1,34 +0,0 @@
-import datetime
-import sys
-import os
-
-try:
- __import__('imp').find_module('sphinx.ext.numfig')
- extensions = ['sphinx.ext.numfig']
-except ImportError:
- # 'pip install sphinx_numfig'
- extensions = ['sphinx_numfig']
-
-# numfig:
-number_figures = True
-figure_caption_prefix = "Fig."
-
-source_suffix = '.rst'
-master_doc = 'index'
-pygments_style = 'sphinx'
-html_use_index = False
-
-pdf_documents = [('index', u'OPNFV', u'OPNFV Project', u'OPNFV')]
-pdf_fit_mode = "shrink"
-pdf_stylesheets = ['sphinx','kerning','a4']
-#latex_domain_indices = False
-#latex_use_modindex = False
-
-latex_elements = {
- 'printindex': '',
-}
-
-project = u'OPNFV: Template documentation config'
-copyright = u'%s, OPNFV' % datetime.date.today().year
-version = u'1.0.0'
-release = u'1.0.0'
@@ -1,86 +0,0 @@
-.. two dots create a comment. please leave this logo at the top of each of your rst files.
-.. image:: ../etc/opnfv-logo.png
- :height: 40
- :width: 200
- :alt: OPNFV
- :align: left
-.. these two pipes are to seperate the logo from the first title
-|
-|
-How to create documentation for your OPNFV project
-==================================================
-
-this is the directory structure of the docs/ directory that can be found in the root of your project directory
-
-.. code-block:: bash
-
- ./etc
- ./etc/opnfv-logo.png
- ./etc/conf.py
- ./how-to-use-docs
- ./how-to-use-docs/documentation-example.rst
- ./how-to-use-docs/index.rst
-
-To create your own documentation, Create any number of directories (depending on your need) and place in each of them an index.rst.
-This index file must refence your other rst files.
-
-* Here is an example index.rst
-
-.. code-block:: bash
-
- Example Documentation table of contents
- =======================================
-
- Contents:
-
- .. toctree::
- :numbered:
- :maxdepth: 4
-
- documentation-example.rst
-
- Indices and tables
- ==================
-
- * :ref:`search`
-
- Revision: _sha1_
-
- Build date: |today|
-
-
-The Sphinx Build
-================
-
-When you push documentation changes to gerrit a jenkins job will create html documentation.
-
-* Verify Jobs
-For verify jobs a link to the documentation will show up as a comment in gerrit for you to see the result.
-
-* Merge jobs
-
-Once you are happy with the look of your documentation you can submit the patchset the merge job will
-copy the output of each documentation directory to http://artifacts.opnfv.org/$project/docs/$name_of_your_folder/index.html
-
-Here are some quick examples of how to use rst markup
-
-This is a headline::
-
- here is some code, note that it is indented
-
-links are easy to add: Here is a link to sphinx, the tool that we are using to generate documetation http://sphinx-doc.org/
-
-* Bulleted Items
-
- **this will be bold**
-
-.. code-block:: bash
-
- echo "Heres is a code block with bash syntax highlighting"
-
-
-Leave these at the bottom of each of your documents they are used internally
-
-Revision: _sha1_
-
-Build date: |today|
diff --git a/docs/how-to-use-docs/index.rst b/docs/how-to-use-docs/index.rst
deleted file mode 100644
index 36710b32d..000000000
--- a/
docs/how-to-use-docs/index.rst+++ /dev/null
@@ -1,30 +0,0 @@
-.. OPNFV Release Engineering documentation, created by
- sphinx-quickstart on Tue Jun 9 19:12:31 2015.
- You can adapt this file completely to your liking, but it should at least
- contain the root `toctree` directive.
-
-.. image:: ../etc/opnfv-logo.png
- :height: 40
- :width: 200
- :alt: OPNFV
- :align: left
-
-Example Documentation table of contents
-=======================================
-
-Contents:
-
-.. toctree::
- :numbered:
- :maxdepth: 4
-
- documentation-example.rst
-
-Indices and tables
-==================
-
-* :ref:`search`
-
-Revision: _sha1_
-
-Build date: |today|
Yunhong Jiang <yunhong.jiang@linux.intel.com>