From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] tcp: splice as many packets as possible at once Date: Mon, 19 Jan 2009 08:40:52 +0000 Message-ID: <20090119084051.GB4788@ff.dom.local> References: <20090115.155434.206643894.davem@davemloft.net> <20090119004206.GA10396@1wt.eu> <20090119030844.GA31941@gondor.apana.org.au> <20090118.192719.198405397.davem@davemloft.net> <20090119061420.GB12946@1wt.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , herbert@gondor.apana.org.au, zbr@ioremap.net, dada1@cosmosbay.com, ben@zeus.com, mingo@elte.hu, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jens.axboe@oracle.com To: Willy Tarreau Return-path: Received: from mail-ew0-f20.google.com ([209.85.219.20]:44701 "EHLO mail-ew0-f20.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753548AbZASIk7 (ORCPT ); Mon, 19 Jan 2009 03:40:59 -0500 Content-Disposition: inline In-Reply-To: <20090119061420.GB12946@1wt.eu> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jan 19, 2009 at 07:14:20AM +0100, Willy Tarreau wrote: > On Sun, Jan 18, 2009 at 07:27:19PM -0800, David Miller wrote: > > From: Herbert Xu > > Date: Mon, 19 Jan 2009 14:08:44 +1100 > > > > > On Mon, Jan 19, 2009 at 01:42:06AM +0100, Willy Tarreau wrote: > > > > > > > > Just for the record, I've now re-integrated those changes in a test kernel > > > > that I booted on my 10gig machines. I have updated my user-space code in > > > > haproxy to run a new series of tests. Eventhough there is a memcpy(), the > > > > results are EXCELLENT (on a C2D 2.66 GHz using Myricom's Myri10GE NICs) : > > > > > > > > - 4.8 Gbps at 100% CPU using MTU=1500 without LRO > > > > (3.2 Gbps at 100% CPU without splice) > > > > > > One thing to note is that Myricom's driver probably uses page > > > frags which means that you're not actually triggering the copy. > > So does this mean that the corruption problem should still there for > such a driver ? I'm asking before testing, because at these speeds, > validity tests are not that easy ;-) I guess, David meant the performance: there is not much change because only a small part could be copied. The most harmed should be jumbo frames in linear only skbs. But no corruption is expected. Jarek P.