off Interfaces will be created with carrier state set to off.
on Interfaces will be created with carrier state set to on.
(charp)
+ parm: enable_bifurcated: Enable request processing support for
+ bifurcated drivers, which means releasing rtnl_lock before calling
+ userspace callback and supporting async requests (default=off):
+ on Enable request processing support for bifurcated drivers.
+ (charp)
+ parm: min_scheduling_interval: KNI thread min scheduling interval (default=100 microseconds)
+ (long)
+ parm: max_scheduling_interval: KNI thread max scheduling interval (default=200 microseconds)
+ (long)
+
Loading the ``rte_kni`` kernel module without any optional parameters is
the typical way a DPDK application gets packets into and out of the kernel
.. code-block:: console
- # insmod kmod/rte_kni.ko
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko
.. _kni_loopback_mode:
.. code-block:: console
- # insmod kmod/rte_kni.ko lo_mode=lo_mode_fifo
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko lo_mode=lo_mode_fifo
The ``lo_mode_fifo`` loopback option will loop back ring enqueue/dequeue
operations in kernel space.
.. code-block:: console
- # insmod kmod/rte_kni.ko lo_mode=lo_mode_fifo_skb
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko lo_mode=lo_mode_fifo_skb
The ``lo_mode_fifo_skb`` loopback option will loop back ring enqueue/dequeue
operations and sk buffer copies in kernel space.
.. code-block:: console
- # insmod kmod/rte_kni.ko kthread_mode=single
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko kthread_mode=single
This mode will create only one kernel thread for all KNI interfaces to
receive data on the kernel side. By default, this kernel thread is not
.. code-block:: console
- # insmod kmod/rte_kni.ko kthread_mode=multiple
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko kthread_mode=multiple
This mode will create a separate kernel thread for each KNI interface to
receive data on the kernel side. The core affinity of each ``kni_thread``
.. code-block:: console
- # insmod kmod/rte_kni.ko carrier=on
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko carrier=on
To set the default carrier state to *off*:
.. code-block:: console
- # insmod kmod/rte_kni.ko carrier=off
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko carrier=off
If the ``carrier`` parameter is not specified, the default carrier state
of KNI interfaces will be set to *off*.
+.. _kni_bifurcated_device_support:
+
+Bifurcated Device Support
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+User callbacks are executed while kernel module holds the ``rtnl`` lock, this
+causes a deadlock when callbacks run control commands on another Linux kernel
+network interface.
+
+Bifurcated devices has kernel network driver part and to prevent deadlock for
+them ``enable_bifurcated`` is used.
+
+To enable bifurcated device support:
+
+.. code-block:: console
+
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko enable_bifurcated=on
+
+Enabling bifurcated device support releases ``rtnl`` lock before calling
+callback and locks it back after callback. Also enables asynchronous request to
+support callbacks that requires rtnl lock to work (interface down).
+
+KNI Kthread Scheduling
+~~~~~~~~~~~~~~~~~~~~~~
+
+The ``min_scheduling_interval`` and ``max_scheduling_interval`` parameters
+control the rescheduling interval of the KNI kthreads.
+
+This might be useful if we have use cases in which we require improved
+latency or performance for control plane traffic.
+
+The implementation is backed by Linux High Precision Timers, and uses ``usleep_range``.
+Hence, it will have the same granularity constraints as this Linux subsystem.
+
+For Linux High Precision Timers, you can check the following resource: `Kernel Timers <http://www.kernel.org/doc/Documentation/timers/timers-howto.txt>`_
+
+To set the ``min_scheduling_interval`` to a value of 100 microseconds:
+
+.. code-block:: console
+
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko min_scheduling_interval=100
+
+To set the ``max_scheduling_interval`` to a value of 200 microseconds:
+
+.. code-block:: console
+
+ # insmod <build_dir>/kernel/linux/kni/rte_kni.ko max_scheduling_interval=200
+
+If the ``min_scheduling_interval`` and ``max_scheduling_interval`` parameters are
+not specified, the default interval limits will be set to *100* and *200* respectively.
+
KNI Creation and Deletion
-------------------------
Before any KNI interfaces can be created, the ``rte_kni`` kernel module must
-be loaded into the kernel and configured withe ``rte_kni_init()`` function.
+be loaded into the kernel and configured with the ``rte_kni_init()`` function.
The KNI interfaces are created by a DPDK application dynamically via the
``rte_kni_alloc()`` function.
KNI operates in IOVA_VA scheme when
-- LINUX_VERSION_CODE > KERNEL_VERSION(4, 9, 0) and
+- LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0) and
- EAL option `iova-mode=va` is passed or bus IOVA scheme in the DPDK is selected
as RTE_IOVA_VA.
git.droids-corp.org / dpdk.git / blobdiff