From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: RFC: NAPI packet weighting patch Date: Fri, 27 May 2005 14:01:32 -0700 Message-ID: <20050527140132.1435132d@dxpl.pdx.osdl.net> References: <20050527085055.79da3d75@dxpl.pdx.osdl.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com, hadi@cyberus.ca, Robert.Olsson@data.slu.se, "Ronciak, John" , "Venkatesan, Ganesh" , "Brandeburg, Jesse" Return-path: To: Mitch Williams In-Reply-To: Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Fri, 27 May 2005 13:27:04 -0700 Mitch Williams wrote: > > Stephen, Robert, and Jamal all replied to my original message, and all > said approximately the same thing: "Why don't you just reduce the weight > in the driver? It does the same thing." > > To which I reply, respectfully, I know that. And no it doesn't, not > exactly. > > My primary reason for adding this setting is to allow for runtime tweaking > -- just like max_backlog has right now. Driver weight is a compile-time > setting, and has to be changed for every driver that you run. > > This setting allows you to scale the weight of all your drivers, at > runtime, in one place. It's complimentary to Stephen's max_weight idea -- > his patch affects how long you spend in any individual softirq; my patch > affects how long you spend in any driver's individual NAPI poll routine, > as well as how long the softirq lasts. > Why not just allow adjusting dev->weight via sysfs?