Thank you for the explanation. I was a little confused as ixgbe documentation only mentioned about Flow Control is enabled by default but nothing that ixgbe can't disable Flow Control automatically. I spent some time investigating a lot of "Discards In" packets. Then found that rx_missed_errors counter increments together with tx_restart_queue, tx_flow_control_xon and tx_flow_control_xoff counters. After comparison between igb and ixgbe drivers behavior found the difference.
Please update ixgbe drivers documentation of course if it is up to you. Best regards, Aleksey -----Original Message----- From: Skidmore, Donald C [mailto:[email protected]] Sent: Friday, December 16, 2011 1:49 AM To: Skidmore, Donald C; Aleksey Chudov; [email protected] Cc: Brandeburg, Jesse Subject: RE: [E1000-devel] ixgbe does not disable Flow Control Hey Aleksey, Jesse Brandeburg just mentioned you might have been talking about autoneg of FC. Which I can understand your confusion. 10GbE Spec doesn't support that. Let me know if this isn't what you were concerned about. Thanks, -Don >-----Original Message----- >From: Skidmore, Donald C >Sent: Thursday, December 15, 2011 2:34 PM >To: 'Aleksey Chudov'; [email protected] >Subject: RE: [E1000-devel] ixgbe does not disable Flow Control > >Hi Aleksey, > >I'm not sure I understand your question here. Are you asking why igb >has FC off by default and ixgbe has it on? If so at least for ixgbe >(the driver I maintain) that was a deliberate choice based on the >majority use case of our customers. If that isn't what your concern >here is could you give me a little more details or reword the question? >Hopefully I can catch on after that. :) > >Thanks, >-Don > >>-----Original Message----- >>From: Aleksey Chudov [mailto:[email protected]] >>Sent: Thursday, December 15, 2011 10:29 AM >>To: [email protected] >>Subject: [E1000-devel] ixgbe does not disable Flow Control >> >>Hello! >> >>I have two servers. One with Intel 82576 Gigabit NIC and second with >>Intel Corporation 82599EB 10-Gigabit NIC installed. >>Both servers connected to Cisco 3750X switch. Flow control is disabled >>by default on all switch ports. >> >>There were Discards In on a second server (82599EB, ixgbe). But after >>manually disabling Flow control they are gone. >> >>As shown below igb driver disable Flow Control but ixgbe does not >>disable Flow Control >> >>Intel 82576 Gigabit NIC >> >># ethtool -i eth0 >>driver: igb >>version: 2.1.0-k2 >>firmware-version: 1.4-3 >> >># ethtool -a eth0 >>Pause parameters for eth0: >>Autonegotiate: on >>RX: on >>TX: off >> >> >>Intel Corporation 82599EB 10-Gigabit NIC >> >># ethtool -i eth4 >>driver: ixgbe >>version: 3.7.14-NAPI >>firmware-version: 0x18f10001 >> >># ethtool -a eth4 >>Pause parameters for eth4: >>Autonegotiate: on >>RX: on >>TX: on >> >> >>Best regards, >>Aleksey >> >> >>---------------------------------------------------------------------- >>- >- >>------ >>10 Tips for Better Server Consolidation Server virtualization is being >>driven by many needs. >>But none more important than the need to reduce IT complexity while >>improving strategic productivity. Learn More! >>http://www.accelacomm.com/jaw/sdnl/114/51507609/ >>_______________________________________________ >>E1000-devel mailing list >>[email protected] >>https://lists.sourceforge.net/lists/listinfo/e1000-devel >>To learn more about Intel® Ethernet, visit >>http://communities.intel.com/community/wired ------------------------------------------------------------------------------ Learn Windows Azure Live! Tuesday, Dec 13, 2011 Microsoft is holding a special Learn Windows Azure training event for developers. It will provide a great way to learn Windows Azure and what it provides. You can attend the event by watching it streamed LIVE online. Learn more at http://p.sf.net/sfu/ms-windowsazure _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
