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[dpdk-dev,PATCHv4,9/9] doc: dynamic rss configuration for bonding

Message ID 1436981189-3320-10-git-send-email-tomaszx.kulasek@intel.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

Tomasz Kulasek July 15, 2015, 5:26 p.m. UTC 
Documentation update about implementation details and requirements for
Dynamic RSS Configuration for Bonding.

Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
---
 .../prog_guide/link_bonding_poll_mode_drv_lib.rst  |   34 ++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)
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Patch

diff --git a/doc/guides/prog_guide/link_bonding_poll_mode_drv_lib.rst b/doc/guides/prog_guide/link_bonding_poll_mode_drv_lib.rst
index 03baf90..46f0296 100644
--- a/doc/guides/prog_guide/link_bonding_poll_mode_drv_lib.rst
+++ b/doc/guides/prog_guide/link_bonding_poll_mode_drv_lib.rst
@@ -1,5 +1,5 @@ 
 ..  BSD LICENSE
-    Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+    Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -173,7 +173,28 @@  After a slave device is added to a bonded device slave is stopped using
 ``rte_eth_dev_stop`` and then reconfigured using ``rte_eth_dev_configure``
 the RX and TX queues are also reconfigured using ``rte_eth_tx_queue_setup`` /
 ``rte_eth_rx_queue_setup`` with the parameters use to configure the bonding
-device.
+device. If RSS is enabled for bonding device, this mode is also enabled on new
+slave and configured as well.
+
+Setting up multi-queue mode for bonding device to RSS, makes it fully
+RSS-capable, so all slaves are synchronized with its configuration. This mode is
+intended to provide RSS configuration on slaves transparent for client
+application implementation.
+
+Bonding device stores its own version of RSS settings i.e. RETA, RSS hash
+function and RSS key, used to set up its slaves. That let to define the meaning
+of RSS configuration of bonding device as desired configuration of whole bonding
+(as one unit), without pointing any of slave inside. It is required to ensure
+consistency and made it more errorproof.
+
+RSS hash function set for bonding device, is a maximal set of RSS hash functions
+supported by all bonded slaves. RETA size is a GCD of all its RETA's sizes, so
+it can be easily used as a pattern providing expected behavior, even if slave
+RETAs' sizes are different. If RSS Key is not set for bonded device, it's not
+changed on the slaves and default key for device is used.
+
+All settings are managed through the bonding port API and always are propagated
+in one direction (from bonding to slaves).
 
 Link Status Change Interrupts / Polling
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -207,6 +228,15 @@  these parameters.
 A bonding device must have a minimum of one slave before the bonding device
 itself can be started.
 
+To use a bonding device dynamic RSS configuration feature effectively, it is
+also required, that all slaves should be RSS-capable and support, at least one
+common hash function available for each of them. Changing RSS key is only
+possible, when all slave devices support the same key size.
+
+To prevent inconsistency on how slaves process packets, once a device is added
+to a bonding device, RSS configuration should be managed through the bonding
+device API, and not directly on the slave.
+
 Like all other PMD, all functions exported by a PMD are lock-free functions
 that are assumed not to be invoked in parallel on different logical cores to
 work on the same target object.