From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751422AbZHZTXA (ORCPT ); Wed, 26 Aug 2009 15:23:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752717AbZHZTW5 (ORCPT ); Wed, 26 Aug 2009 15:22:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2828 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbZHZTW4 (ORCPT ); Wed, 26 Aug 2009 15:22:56 -0400 Message-ID: <4A958BA0.2000801@redhat.com> Date: Wed, 26 Aug 2009 22:23:12 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Gregory Haskins CC: alacrityvm-devel@lists.sourceforge.net, "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Michael S. Tsirkin" , netdev@vger.kernel.org Subject: Re: AlacrityVM benchmark numbers updated References: <4A948962.7090909@gmail.com> <4A950B75.5020409@redhat.com> <4A95822D.9060207@gmail.com> In-Reply-To: <4A95822D.9060207@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/26/2009 09:42 PM, Gregory Haskins wrote: > Actually, I have already look at this and it does indeed seem better to > use switch_mm+gupf() over gup() by quite a large margin. You could then > couple that with your DMA-engine idea to potentially gain even more > benefits (though probably not for networking since most NICs have their > own DMA engine anyway). > > For tx, we'll just go copyless once we plumb the destructors properly. But for rx on a shared interface it is impossible to avoid the copy. You can only choose if you want it done by the cpu or a local dma engine. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.