From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shirley Ma <mashirle@us.ibm.com>
Subject: Re: vhost-net patches
Date: Wed, 28 Oct 2009 11:12:17 -0700
Message-ID: <1256753537.24155.3.camel@localhost.localdomain>
References: <1256310765.4443.4.camel@localhost.localdomain>
	 <1256315020.4443.12.camel@localhost.localdomain>
	 <20091026200513.GA26623@redhat.com>
	 <1256592889.10142.8.camel@localhost.localdomain>
	 <20091027064302.GB26914@redhat.com>
	 <1256654819.4753.6.camel@localhost.localdomain>
	 <20091027152753.GA4622@redhat.com>
	 <1256661378.6745.2.camel@localhost.localdomain>
	 <20091028153859.GA28926@redhat.com>
	 <1256748337.6433.11.camel@localhost.localdomain>
	 <20091028165302.GB29235@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Cc: Sridhar Samudrala <sri@us.ibm.com>, Shirley Ma <xma@us.ibm.com>,
	David Stevens <dlstevens@us.ibm.com>, kvm@vger.kernel.org,
	sri@linux.vnet.ibm.com, mashirle@linux.vnet.ibm.com
To: "Michael S. Tsirkin" <mst@redhat.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from e2.ny.us.ibm.com ([32.97.182.142]:54135 "EHLO e2.ny.us.ibm.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1753000AbZJ1SMP (ORCPT <rfc822;kvm@vger.kernel.org>);
	Wed, 28 Oct 2009 14:12:15 -0400
Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233])
	by e2.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id n9SI4mS8007546
	for <kvm@vger.kernel.org>; Wed, 28 Oct 2009 14:04:48 -0400
Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217])
	by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n9SICJa6103362
	for <kvm@vger.kernel.org>; Wed, 28 Oct 2009 14:12:19 -0400
Received: from d01av03.pok.ibm.com (loopback [127.0.0.1])
	by d01av03.pok.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id n9S8Clhn003140
	for <kvm@vger.kernel.org>; Wed, 28 Oct 2009 04:12:47 -0400
In-Reply-To: <20091028165302.GB29235@redhat.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

Hello Miachel,

On Wed, 2009-10-28 at 18:53 +0200, Michael S. Tsirkin wrote:
> what exactly do you mean by transmission queue size?
> tx_queue_len?
> I think what should help with transmission queue full is
> actually sndbuf parameter for tap in qemu.

I didn't see my email out, I resend the response here.
What I meant is the number of descriptors in transmission queue. To be
more specific, it is 256->1024 in hw/virtio-net.c file

   n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);

I had a patch to have trans/recv descriptors configurable rather than
fixed before. But the test results doens't show any difference for both
TCP and UDP, so I didn't submit the patch. I think it's better to make
it configurable based on how much memory virtio-net can be used. 

Thanks
Shirley