From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932105AbdHUV5a (ORCPT ); Mon, 21 Aug 2017 17:57:30 -0400 Received: from a2nlsmtp01-05.prod.iad2.secureserver.net ([198.71.225.49]:45504 "EHLO a2nlsmtp01-05.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754493AbdHUV5Z (ORCPT ); Mon, 21 Aug 2017 17:57:25 -0400 x-originating-ip: 107.180.71.197 From: Haiyang Zhang To: davem@davemloft.net, netdev@vger.kernel.org Cc: haiyangz@microsoft.com, kys@microsoft.com, olaf@aepfle.de, vkuznets@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH net-next,4/4] hv_netvsc: Update netvsc Document for UDP hash level setting Date: Mon, 21 Aug 2017 14:55:55 -0700 Message-Id: <1503352555-9256-4-git-send-email-haiyangz@exchange.microsoft.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1503352555-9256-1-git-send-email-haiyangz@exchange.microsoft.com> References: <1503352555-9256-1-git-send-email-haiyangz@exchange.microsoft.com> Reply-To: haiyangz@microsoft.com X-CMAE-Envelope: MS4wfK5vAQlMcSt74RiSyl59FJoPdAuZ3nFf4t1OR/H2N221oqUi1BUOl14PqlfW/b9YPFOyGSMOqtVWjRtvFo5sOKdASv1dzNAmQMGSGLXX+ZOu2HmeO1lh QFsA/nN3WCTo4V1PQ6RnNeUz6pO1dVeAFGuublMLbnDgr9oRDwQAf+cyjyZRdX7gk948kA2GSIvztgmBtCJWER4r8RilLwDwoYsQX/tzbRoNwtxVpEe2CVWH vnKqlY1z1shJNj+eQkmgrJSep3MQph+spPd1MY5NATe61TgKTCv+aOHAgXnkwHm8S7HoXN9EPlNYY8633ceYJT8GJ9dC5O1o6V8fgzhl00hbo0HMaRz9J0rv T8IwTVDUx+FlLK9J/VrpQ5VH4cTcTg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Haiyang Zhang Update Documentation/networking/netvsc.txt for UDP hash level setting and related info. Signed-off-by: Haiyang Zhang --- Documentation/networking/netvsc.txt | 22 +++++++++++++++++----- 1 files changed, 17 insertions(+), 5 deletions(-) diff --git a/Documentation/networking/netvsc.txt b/Documentation/networking/netvsc.txt index 4ddb4e4..fa8d863 100644 --- a/Documentation/networking/netvsc.txt +++ b/Documentation/networking/netvsc.txt @@ -21,11 +21,23 @@ Features -------------------- Hyper-V supports receive side scaling. For TCP, packets are distributed among available queues based on IP address and port - number. Current versions of Hyper-V host, only distribute UDP - packets based on the IP source and destination address. - The port number is not used as part of the hash value for UDP. - Fragmented IP packets are not distributed between queues; - all fragmented packets arrive on the first channel. + number. + + For UDP, we can switch UDP hash level between L3 and L4 by ethtool + command. UDP over IPv4 and v6 can be set differently. The default + hash level is L4. We currently only allow switching TX hash level + from within the guests. + + On Azure, fragmented UDP packets have high loss rate with L4 + hashing. Using L3 hashing is recommended in this case. + + For example, for UDP over IPv4 on eth0: + To include UDP port numbers in hasing: + ethtool -N eth0 rx-flow-hash udp4 sdfn + To exclude UDP port numbers in hasing: + ethtool -N eth0 rx-flow-hash udp4 sd + To show UDP hash level: + ethtool -n eth0 rx-flow-hash udp4 Generic Receive Offload, aka GRO -------------------------------- -- 1.7.1