From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Gallatin Subject: Re: [PATCH] myr10ge: again fix lro_gen_skb() alignment Date: Fri, 24 Apr 2009 08:45:28 -0400 Message-ID: <49F1B468.7020605@myri.com> References: <20090415.030213.249634462.davem@davemloft.net> <49E5DABB.9070806@myri.com> <49E64BE4.1050908@myri.com> <20090415.164248.188350673.davem@davemloft.net> <20090416085022.GA19731@gondor.apana.org.au> <49EE1C32.1060202@myri.com> <20090422104811.GA30981@gondor.apana.org.au> <49EF39B4.1040607@myri.com> <20090424054557.GA24575@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , brice@myri.com, sgruszka@redhat.com, netdev@vger.kernel.org To: Herbert Xu Return-path: Received: from mailbox2.myri.com ([64.172.73.26]:1887 "EHLO myri.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753525AbZDXMq1 (ORCPT ); Fri, 24 Apr 2009 08:46:27 -0400 In-Reply-To: <20090424054557.GA24575@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: Herbert Xu wrote: > On Wed, Apr 22, 2009 at 11:37:24AM -0400, Andrew Gallatin wrote: >> I booted the sender into a kernel.org 2.6.18.2 so as to try to have >> results as close to yours as possible (I was running 2.6.22 on the >> sender before). > > OK I've got my hands on a myricom card. I've tested it using the > same 2.6.18 sender that I used against the eariler cxgb3 test. > I wasn't able to discern any significant deviations between LRO > and GRO. > > Unfortunately it seems that this machine is a little too fast > so even with the IRQ bound to a single CPU it's way overspeced > for 10GbE: > > Idle at 10Gb IRQ rate soaker IRQ rate soaker throuput > GRO 43-45 14700 13300 7933 > LRO 43-45 14700 13300 7943 > > But even with the soaker running they seem to be neck and neck. This is strange. I wonder if it might be a cache footprint issue? My intentionally weak receiver is an athlon64 x2 "Toledo", and has only 512KB L2 cache. I can re-test with a core-2 based Xeon. But can you describe your setup in more detail? What CPU does the receiver have? You say the sender is running 2.6.18. Is this a RHEL5 kernel, or a kernel.org kernel? > Here's the patch I used BTW. I got the checksums to work by > just setting skb->csum. Yes, sorry about that stupidity. Drew