X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Fprog_guide%2Fswitch_representation.rst;h=4f2532a91ea3a14a06b7fea69d781725b5567238;hb=6cc51b1293ceac4a77d4bf7ac91a8bbd59e1f78c;hp=ff6aa91c80663bdf0b06b70122fd54af35c3c007;hpb=fa4f3fecb9688af1ece6a1c1c544d7758c39ef4e;p=dpdk.git

diff --git a/doc/guides/prog_guide/switch_representation.rst b/doc/guides/prog_guide/switch_representation.rst
index ff6aa91c80..4f2532a91e 100644
--- a/doc/guides/prog_guide/switch_representation.rst
+++ b/doc/guides/prog_guide/switch_representation.rst
@@ -123,6 +123,17 @@ thought as a software "patch panel" front-end for applications.
 .. [1] `Ethernet switch device driver model (switchdev)
        <https://www.kernel.org/doc/Documentation/networking/switchdev.txt>`_
 
+- For some PMDs, memory usage of representors is huge when number of
+  representor grows, mbufs are allocated for each descriptor of Rx queue.
+  Polling large number of ports brings more CPU load, cache miss and
+  latency. Shared Rx queue can be used to share Rx queue between PF and
+  representors among same Rx domain. ``RTE_ETH_DEV_CAPA_RXQ_SHARE`` in
+  device info is used to indicate the capability. Setting non-zero share
+  group in Rx queue configuration to enable share, share_qid is used to
+  identify the shared Rx queue in group. Polling any member port can
+  receive packets of all member ports in the group, port ID is saved in
+  ``mbuf.port``.
+
 Basic SR-IOV
 ------------