From: Dariusz Sosnowski <dsosnowski@nvidia.com>
To: Matan Azrad <matan@nvidia.com>,
Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Cc: <dev@dpdk.org>
Subject: [PATCH v2 6/8] doc: add notes for hairpin to mlx5 documentation
Date: Thu, 6 Oct 2022 11:01:03 +0000 [thread overview]
Message-ID: <20221006110105.2986966-7-dsosnowski@nvidia.com> (raw)
In-Reply-To: <20221006110105.2986966-1-dsosnowski@nvidia.com>
This patch extends mlx5 PMD documentation with more information
regarding hairpin support.
The following is added to mlx5 PMD documentation:
- description of the default behavior of hairpin queues,
- description of use_locked_device_memory effect on hairpin queue
configuration,
- description of use_rte_memory effect on hairpin queue configuration,
- DPDK and OFED requirements for new memory options for hairpin.
Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
doc/guides/nics/mlx5.rst | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 3d4ee31f8d..997cb19ba2 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -1517,6 +1517,43 @@ behavior as librte_net_mlx4::
> port config all rss all
> port start all
+Notes for hairpin
+-----------------
+
+NVIDIA Connect-X and BlueField devices support specifying memory
+placement for hairpin Rx and Tx queues. This feature requires OFED 5.8.
+
+By default, data buffers and packet descriptors for hairpin queues are placed
+in device memory which is shared with other resources (e.g. flow rules).
+
+Starting with DPDK 22.11 and OFED 5.8 applications are allowed to:
+
+#. Place data buffers and Rx packet descriptors in dedicated device memory.
+ Application can request that configuration through ``use_locked_device_memory``
+ configuration option.
+
+ Placing data buffers and Rx packet descriptors in dedicated device memory
+ can decrease latency on hairpinned traffic, since traffic processing
+ for the hairpin queue will not be memory starved.
+
+ However, reserving device memory for hairpin Rx queues may decrease throughput
+ under heavy load, since less resources will be available on device.
+
+ This option is supported only for Rx hairpin queues.
+
+#. Place Tx packet descriptors in host memory.
+ Application can request that configuration through ``use_rte_memory``
+ configuration option.
+
+ Placing Tx packet descritors in host memory can increase traffic throughput.
+ This results in more resources available on the device for other purposes,
+ which reduces memory contention on device.
+ Side effect of this option is visible increase in latency, since each packet
+ incurs additional PCI transactions.
+
+ This option is supported only for Tx hairpin queues.
+
+
Usage example
-------------
--
2.25.1
next prev parent reply other threads:[~2022-10-06 11:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-19 16:37 [PATCH 0/7] ethdev: introduce hairpin memory capabilities Dariusz Sosnowski
2022-09-19 16:37 ` [PATCH 1/7] " Dariusz Sosnowski
2022-10-04 16:50 ` Thomas Monjalon
2022-10-06 11:21 ` Dariusz Sosnowski
2022-09-19 16:37 ` [PATCH 2/7] common/mlx5: add hairpin SQ buffer type capabilities Dariusz Sosnowski
2022-09-27 13:03 ` Slava Ovsiienko
2022-09-19 16:37 ` [PATCH 3/7] common/mlx5: add hairpin RQ " Dariusz Sosnowski
2022-09-27 13:04 ` Slava Ovsiienko
2022-09-19 16:37 ` [PATCH 4/7] net/mlx5: allow hairpin Tx queue in RTE memory Dariusz Sosnowski
2022-09-27 13:05 ` Slava Ovsiienko
2022-09-19 16:37 ` [PATCH 5/7] net/mlx5: allow hairpin Rx queue in locked memory Dariusz Sosnowski
2022-09-27 13:04 ` Slava Ovsiienko
2022-11-25 14:06 ` Kenneth Klette Jonassen
2022-09-19 16:37 ` [PATCH 6/7] app/testpmd: add hairpin queues memory modes Dariusz Sosnowski
2022-09-19 16:37 ` [PATCH 7/7] app/flow-perf: add hairpin queue memory config Dariusz Sosnowski
2022-10-04 12:24 ` Wisam Monther
2022-10-06 11:06 ` Dariusz Sosnowski
2022-10-04 16:44 ` [PATCH 0/7] ethdev: introduce hairpin memory capabilities Thomas Monjalon
2022-10-06 11:08 ` Dariusz Sosnowski
2022-10-06 11:00 ` [PATCH v2 0/8] " Dariusz Sosnowski
2022-10-06 11:00 ` [PATCH v2 1/8] " Dariusz Sosnowski
2022-10-06 11:00 ` [PATCH v2 2/8] common/mlx5: add hairpin SQ buffer type capabilities Dariusz Sosnowski
2022-10-06 11:01 ` [PATCH v2 3/8] common/mlx5: add hairpin RQ " Dariusz Sosnowski
2022-10-06 11:01 ` [PATCH v2 4/8] net/mlx5: allow hairpin Tx queue in RTE memory Dariusz Sosnowski
2022-10-06 11:01 ` [PATCH v2 5/8] net/mlx5: allow hairpin Rx queue in locked memory Dariusz Sosnowski
2022-10-06 11:01 ` Dariusz Sosnowski [this message]
2022-10-06 11:01 ` [PATCH v2 7/8] app/testpmd: add hairpin queues memory modes Dariusz Sosnowski
2022-10-06 11:01 ` [PATCH v2 8/8] app/flow-perf: add hairpin queue memory config Dariusz Sosnowski
2022-10-15 16:30 ` Wisam Monther
2022-10-08 16:31 ` [PATCH v2 0/8] ethdev: introduce hairpin memory capabilities Thomas Monjalon
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