From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [net-next 11/13] igb: Make Tx budget for NAPI user adjustable Date: Sat, 17 Sep 2011 18:04:01 +0100 Message-ID: <1316279044.14749.179.camel@deadeye> References: <1316246677-8830-1-git-send-email-jeffrey.t.kirsher@intel.com> <1316246677-8830-12-git-send-email-jeffrey.t.kirsher@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, Alexander Duyck , netdev@vger.kernel.org, gospo@redhat.com To: Jeff Kirsher Return-path: Received: from mail.solarflare.com ([216.237.3.220]:52169 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751971Ab1IQREL (ORCPT ); Sat, 17 Sep 2011 13:04:11 -0400 In-Reply-To: <1316246677-8830-12-git-send-email-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2011-09-17 at 01:04 -0700, Jeff Kirsher wrote: > From: Alexander Duyck > > This change is meant to make the NAPI budget limits for transmit > adjustable. By doing this it is possible to tune the value for optimal > performance with applications such as routing. [...] > --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c > +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c > @@ -1989,6 +1989,9 @@ static int igb_set_coalesce(struct net_device *netdev, > if ((adapter->flags & IGB_FLAG_QUEUE_PAIRS) && ec->tx_coalesce_usecs) > return -EINVAL; > > + if (ec->tx_max_coalesced_frames_irq) > + adapter->tx_work_limit = ec->tx_max_coalesced_frames_irq; > + [...] I don't think it really makes sense to conflate NAPI and interrupt moderation parameters. This really ought to be added to NAPI itself. (NAPI contexts really ought to be exposed through sysfs somehow. I think we've discussed this before, and it's tricky due to the lack of a consistent mapping between those contexts and net devices.) Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.