From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [PATCH] igb: add module param to set max-rss-queues. Date: Fri, 24 Mar 2017 18:35:28 -0700 Message-ID: References: <1490389127-23171-1-git-send-email-greearb@candelatech.com> <20170324.141237.1992801159655201421.davem@davemloft.net> <255aaae0-8634-c6b5-f4aa-545d2f717aed@candelatech.com> <20170324161457.13d86ee0@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:36630 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965359AbdCYBfa (ORCPT ); Fri, 24 Mar 2017 21:35:30 -0400 In-Reply-To: <20170324161457.13d86ee0@xeon-e3> Sender: netdev-owner@vger.kernel.org List-ID: On 03/24/2017 04:14 PM, Stephen Hemminger wrote: > On Fri, 24 Mar 2017 14:20:56 -0700 > Ben Greear wrote: > >> On 03/24/2017 02:12 PM, David Miller wrote: >>> From: greearb@candelatech.com >>> Date: Fri, 24 Mar 2017 13:58:47 -0700 >>> >>>> From: Ben Greear >>>> >>>> In systems where you may have a very large number of network >>>> adapters, certain drivers may consume an unfair amount of >>>> IRQ resources. So, allow a module param that will limit the >>>> number of IRQs at driver load time. This way, other drivers >>>> (40G Ethernet, for instance), which probably will need the >>>> multiple IRQs more, will not be starved of IRQ resources. >>>> >>>> Signed-off-by: Ben Greear >>> >>> Sorry, no module params. >>> >>> Use generic run-time facilities such as ethtool to configure >>> such things. >> >> You cannot call ethtool before module load time, and that is when >> the IRQs are first acquired. It may be way more useful to give each >> of 20 network adapters 2 irqs than have the first few grab 16 and the rest >> get lumped into legacy crap. > > Almost all network devices do not acquire interrupts until device is brought up. > I.e request_irq is called from open not probe. This is done so that configuration > can be done and also so that unused ports don't consume interrupt space. If I ever have to deal with this on stock kernels again I'll keep that in mind. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com