[dpdk-dev] [PATCH] doc: update RSS action with best effort

Ori Kam orika at mellanox.com
Mon Aug 3 16:28:24 CEST 2020


Using the rte_flow action RSS types field,
may result in an undefined outcome.

For example selecting both UDP and TCP,
selecting TCP RSS type but the pattern is targeting UDP traffic.
another option is that the PMD doesn't support all requested types.

Until now, it wasn't clear what will happen in such cases.
This commit clarify this issue by stating that the PMD
will work in the best-effort mode.

Signed-off-by: Ori Kam <orika at mellanox.com>
---
 doc/guides/prog_guide/rte_flow.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 3e5cd1e..d000560 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -1735,6 +1735,16 @@ unspecified "best-effort" settings from the underlying PMD, which depending
 on the flow rule, may result in anything ranging from empty (single queue)
 to all-inclusive RSS.
 
+Best effort will be used, in case there is a conflict inside the rule.
+The conflict can be the result of:
+
+- Conflicting RSS types, for example setting both UDP and TCP.
+
+- Conflicting between RSS types and the requested pattern to match,
+  for example matching on UDP and hashing RSS on TCP.
+
+- Hashing on types that are not supported by the PMD.
+
 Note: RSS hash result is stored in the ``hash.rss`` mbuf field which
 overlaps ``hash.fdir.lo``. Since `Action: MARK`_ sets the ``hash.fdir.hi``
 field only, both can be requested simultaneously.
-- 
1.8.3.1



More information about the dev mailing list