From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 2.6.37-rc1] net-next: Add multiqueue support to vmxnet3 driver v3 Date: Wed, 17 Nov 2010 09:27:22 -0800 (PST) Message-ID: <20101117.092722.193716325.davem@davemloft.net> References: <1290014618.2588.50.camel@bwh-desktop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: sbhatewara@vmware.com, shemminger@vyatta.com, netdev@vger.kernel.org, pv-drivers@vmware.com, linux-kernel@vger.kernel.org To: bhutchings@solarflare.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:51280 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754518Ab0KQR05 (ORCPT ); Wed, 17 Nov 2010 12:26:57 -0500 In-Reply-To: <1290014618.2588.50.camel@bwh-desktop> Sender: netdev-owner@vger.kernel.org List-ID: From: Ben Hutchings Date: Wed, 17 Nov 2010 17:23:38 +0000 > On Tue, 2010-11-16 at 21:14 -0800, Shreyas Bhatewara wrote: > [...] >> Okay. I am resending the patch with no module params what-so-ever. The default >> is no-multiqueue though. Single queue code has matured and is optimized for >> performance. Multiqueue code has got relatively lesser performance tuning. Since >> there is no way to switch between the two modes as of now, it only makes sense >> to keep the best known as default. When configuration knobs are introduced >> later, multiqueue can be made default. > > But so far as I can see there is currently *no* way to enable multiqueue > without editing the code. Perhaps there could be an experimental config > option that people can use to enable and test it now, before we sort out > the proper API? It should be turned on by default, otherwise don't add the code until it's "ready." We had slight performance regressions in the past when various drivers added multiqueue support, but the aggregate performance increased for multi-flow cases, and this was deemed a fine tradeoff. I was hoping you'd use similar logic. Otherwise, send this stuff when it's ready, and no sooner.