From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH 08/24] net, diet: Make TCP metrics optional Date: Wed, 7 May 2014 06:33:46 +0200 Message-ID: <20140507043346.GE5619@two.firstfloor.org> References: <20140506032114.GP2382@two.firstfloor.org> <20140505.232327.578134514220748085.davem@davemloft.net> <20140506155703.GA20391@cloud> <20140506.115941.428706504757835279.davem@davemloft.net> <20140506164108.GA20536@cloud> <20140506191447.GB4137@netboy> <20140506195049.GO19657@tassilo.jf.intel.com> <20140506200738.GA17813@netboy> <20140506210549.GR19657@tassilo.jf.intel.com> <1399418979.15399.107.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , Richard Cochran , josh@joshtriplett.org, David Miller , andi@firstfloor.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tom.zanussi@linux.intel.com To: Eric Dumazet Return-path: Content-Disposition: inline In-Reply-To: <1399418979.15399.107.camel@edumazet-glaptop2.roam.corp.google.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, May 06, 2014 at 04:29:39PM -0700, Eric Dumazet wrote: > On Tue, 2014-05-06 at 14:05 -0700, Andi Kleen wrote: > > > - Make GRO optional. > > This is purely a performance feature for high bandwidth. > > Make this properly then, instead of relying on LTO. > > We did preliminary work to put this stuff in separate files, but its not > complete yet. FWIW doesn't matter for LTO. > > tcpv4_offload has pointers to tcp4_gro_receive() and tcp4_gro_complete() > > Is LTO smart enough to understand this will never be called, and do > proper code elimination of whole _gro_ helpers ? When there are pointers in static objects it cannot eliminate it for C (it may work for C++) However if you just remove the pointer it'll remove the rest. -Andi -- ak@linux.intel.com -- Speaking for myself only.