From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Virtio-for-kvm] [PATCH 7/7] userspace virtio Date: Sun, 23 Dec 2007 12:56:45 +0200 Message-ID: <476E3EED.8070005@qumranet.com> References: <476BD1A9.2040701@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , virtualization To: dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org Return-path: In-Reply-To: <476BD1A9.2040701-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Dor Laor wrote: > From f244bcad756c4f761627557bb7f315b1d8f22fb2 Mon Sep 17 00:00:00 2001 > From: Dor Laor > Date: Thu, 20 Dec 2007 13:26:30 +0200 > Subject: [PATCH] [VIRTIO-NET] Rx performance improvement > The current performance are not good enough, the problem lies > in qemu tap handling code that caused to pass packets one at > a time and also to copy them to a temporal buffer. > > This patch prevents qemu handlers from reading the tap and instead > it selects the tap descriptors for virtio devices. > This eliminates copies and also batch guest notifications (interrupts). > > Using this patch the rx performance reaches 800Mbps. > The patch does not follow qemu's api since the intention is first to have > a better io in kvm and then to polish it correctly. > > This breaks -net user, which is one of the motivations for having a qemu net device. We need to maintain the old path for that, and only use the new fast path if using -net tap. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/