-.. BSD LICENSE
- Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
- All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the
- distribution.
- * Neither the name of Intel Corporation nor the names of its
- contributors may be used to endorse or promote products derived
- from this software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright(c) 2010-2014 Intel Corporation.
.. _Enabling_Additional_Functionality:
.. _High_Precision_Event_Timer:
-High Precision Event Timer HPET) Functionality
-----------------------------------------------
+High Precision Event Timer (HPET) Functionality
+-----------------------------------------------
BIOS Support
~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
By default, HPET support is disabled in the DPDK build configuration files.
-To use HPET, the ``CONFIG_RTE_LIBEAL_USE_HPET`` setting should be changed to ``y``, which will enable the HPET settings at compile time.
+To use HPET, use the following meson build option which will enable the HPET settings at compile time::
+
+ meson configure -Duse_hpet=true
For an application to use the ``rte_get_hpet_cycles()`` and ``rte_get_hpet_hz()`` API calls,
and optionally to make the HPET the default time source for the rte_timer library,
Running DPDK Applications Without Root Privileges
--------------------------------------------------------
+.. note::
+
+ The instructions below will allow running DPDK as non-root with older
+ Linux kernel versions. However, since version 4.0, the kernel does not allow
+ unprivileged processes to read the physical address information from
+ the pagemaps file, making it impossible for those processes to use HW
+ devices which require physical addresses
+
Although applications using the DPDK use network ports and other hardware resources directly,
with a number of small permission adjustments it is possible to run these applications as a user other than "root".
To do so, the ownership, or permissions, on the following Linux file system objects should be adjusted to ensure that
----------------------------------
To run the DPDK Kernel NIC Interface (KNI) sample application, an extra kernel module (the kni module) must be loaded into the running kernel.
-The module is found in the kmod sub-directory of the DPDK target directory.
-Similar to the loading of the ``igb_uio`` module, this module should be loaded using the insmod command as shown below
-(assuming that the current directory is the DPDK target directory):
-
-.. code-block:: console
+The module is found in the kernel/linux sub-directory of the DPDK build directory.
+It should be loaded using the insmod command::
- insmod kmod/rte_kni.ko
+ insmod <build_dir>/kernel/linux/kni/rte_kni.ko
.. note::
Also, if ``INTEL_IOMMU_DEFAULT_ON`` is not set in the kernel, the ``intel_iommu=on`` kernel parameter must be used too.
This ensures that the Intel IOMMU is being initialized as expected.
-Please note that while using ``iommu=pt`` is compulsory for ``igb_uio driver``, the ``vfio-pci`` driver can actually work with both ``iommu=pt`` and ``iommu=on``.
-
-High Performance of Small Packets on 40G NIC
---------------------------------------------
-
-As there might be firmware fixes for performance enhancement in latest version
-of firmware image, the firmware update might be needed for getting high performance.
-Check with the local Intel's Network Division application engineers for firmware updates.
-Users should consult the release notes specific to a DPDK release to identify
-the validated firmware version for a NIC using the i40e driver.
-
-Use 16 Bytes RX Descriptor Size
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-As i40e PMD supports both 16 and 32 bytes RX descriptor sizes, and 16 bytes size can provide helps to high performance of small packets.
-Configuration of ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC`` in config files can be changed to use 16 bytes size RX descriptors.
-
-High Performance and per Packet Latency Tradeoff
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Due to the hardware design, the interrupt signal inside NIC is needed for per
-packet descriptor write-back. The minimum interval of interrupts could be set
-at compile time by ``CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL`` in configuration files.
-Though there is a default configuration, the interval could be tuned by the
-users with that configuration item depends on what the user cares about more,
-performance or per packet latency.
+Please note that while using ``iommu=pt`` is compulsory for ``igb_uio`` driver,
+the ``vfio-pci`` driver can actually work with both ``iommu=pt`` and ``iommu=on``.
git.droids-corp.org / dpdk.git / blobdiff