From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kok, Auke" Subject: Re: [RFC] restore netdev_priv optimization (planb) Date: Fri, 17 Aug 2007 18:21:25 -0700 Message-ID: <46C64995.4030401@intel.com> References: <20070817161928.6b6302fd@freepuppy.rosehill.hemminger.net> <20070817.165625.23014105.davem@davemloft.net> <20070817174909.5e890ad6@freepuppy.rosehill.hemminger.net> <20070817.180006.98552435.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: shemminger@linux-foundation.org, netdev@vger.kernel.org To: David Miller Return-path: Received: from vms042pub.verizon.net ([206.46.252.42]:59381 "EHLO vms042pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750994AbXHRBVj (ORCPT ); Fri, 17 Aug 2007 21:21:39 -0400 Received: from ahkok-mobl.jf.intel.com ([71.182.85.189]) by vms042.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0JMY003WA3RQAE72@vms042.mailsrvcs.net> for netdev@vger.kernel.org; Fri, 17 Aug 2007 20:21:26 -0500 (CDT) In-reply-to: <20070817.180006.98552435.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org David Miller wrote: > From: Stephen Hemminger > Date: Fri, 17 Aug 2007 17:49:09 -0700 > >> Fix optimization of netdev_priv() lost by the addition of multiqueue. >> >> Only configurations that define MULITQUEUE need the extra overhead in >> netdevice structure and the loss of the netdev_priv optimization. >> >> Signed-off-by: Stephen Hemminger > > Every distribution vendor is going to turn MULTIQUEUE on. Therefore > %99 of Linux users will not see any gain from your patch. > > You're walking around in a dark room and hitting walls every > few seconds. Take a moment and think about how to really deal > with this generically for a second before churning out another > patch. > > For example, how about making the multiqueue limit fixed, say at 64 > queues, and declare the egress_queues as an array of 64 entries. Then > you can get constant pointer formation for both the netdev priv and > the queues. this sounds highly optimistic ("64 queues is enough for everyone"?) and probably will be quickly outdated by both hardware and demand... Auke