From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: Low performance Intel 10GE NIC (3.2.10) on 2.6.38 Kernel Date: Thu, 14 Apr 2011 09:42:25 -0700 Message-ID: <4DA723F1.7000901@intel.com> References: <1302253651.4409.2.camel@edumazet-laptop> <1302267400.4409.22.camel@edumazet-laptop> <1302275223.4409.36.camel@edumazet-laptop> <1302330998.2656.113.camel@edumazet-laptop> <4DA3151B.4030507@intel.com> <1302536577.4605.1.camel@edumazet-laptop> <1302761251.3549.198.camel@edumazet-laptop> <1302762810.3549.233.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Eric Dumazet , Peter Zijlstra , netdev , "Kirsher, Jeffrey T" To: Wei Gu Return-path: Received: from mga01.intel.com ([192.55.52.88]:31569 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968Ab1DNQnM (ORCPT ); Thu, 14 Apr 2011 12:43:12 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 4/13/2011 11:58 PM, Wei Gu wrote: > I did the single flow test, it shows no rx error with 300kpps. While = I was start multiple flow with same 300Kpps traffic, then it looks real= ly bad with high rx_missing_error. > > Multiple Flow: > SUM: 191925 ETH8: 0 ETH10: 191925 ETH6: 0 ETH4: 0 > SUM: 214634 ETH8: 0 ETH10: 214634 ETH6: 0 ETH4: 0 > SUM: 237600 ETH8: 0 ETH10: 237600 ETH6: 0 ETH4: 0 > SUM: 198925 ETH8: 0 ETH10: 198925 ETH6: 0 ETH4: 0 > SUM: 249290 ETH8: 0 ETH10: 249290 ETH6: 0 ETH4: 0 > > Single Flow: > SUM: 302018 ETH8: 0 ETH10: 302018 ETH6: 0 ETH4: 0 > SUM: 301849 ETH8: 0 ETH10: 301849 ETH6: 0 ETH4: 0 > SUM: 302163 ETH8: 0 ETH10: 302163 ETH6: 0 ETH4: 0 > > Thanks > WeiGu > -----Original Message----- > From: Eric Dumazet [mailto:eric.dumazet@gmail.com] > Sent: Thursday, April 14, 2011 2:34 PM > To: Wei Gu > Cc: Alexander Duyck; Peter Zijlstra; netdev; Kirsher, Jeffrey T > Subject: RE: Low performance Intel 10GE NIC (3.2.10) on 2.6.38 Kernel > > Le jeudi 14 avril 2011 =E0 08:07 +0200, Eric Dumazet a =E9crit : >> Le jeudi 14 avril 2011 =E0 13:42 +0800, Wei Gu a =E9crit : >>> Hi guys, >>> Do you think it was a bug in the kernel from 2.6.35.2 with Intel 10= GE ixgbe driver? >>> If so shall I issue a Bug on the bugzilla, and which category? Caus= e I'm not sure it was driver problem Or sched problem. >> >> This makes no sense to me. >> >> What is the maximum throughput you can get in pps before having pack= et >> drops ? >> >> Please try with a single flow (to hit one queue, one cpu) >> >> Thanks >> > > Also, please try to check if using smaller or bigger packets makes an= y change in this max throughput > > The only issue I have found so far with the ixgbe driver is the fact=20 that apparently rx_no_buffer_count is apparently always going to be 0 o= n=20 82599, and that isn't so much a driver problem as a hardware limitation= =20 as the HW counter was removed in 82599. However since the hardware was= =20 capable of going faster on the other kernels what this likely means is=20 that the rx_missed_errors are due to the driver not providing Rx buffer= s=20 fast enough. I'm doing some more digging into this now. One thought that occurred t= o=20 me is that if the patch you mention is having some sort of effect this=20 could be a sign of perhaps a kernel timer or scheduling problem. Thanks, Alex