From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: loaded router, excessive getnstimeofday in oprofile Date: Wed, 27 Aug 2008 09:49:10 -0700 Message-ID: <48B58586.3080806@hp.com> References: <200808220457.40892.denys@visp.net.lb> <20080826201406.GA24827@2ka.mipt.ru> <48B46B48.7030609@cosmosbay.com> <20080826205158.GA15266@2ka.mipt.ru> <87vdxmr53f.fsf@basil.nowhere.org> <48B57BD3.5050206@hp.com> <20080827162735.GW26610@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Evgeniy Polyakov , Eric Dumazet , Denys Fedoryshchenko , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Andi Kleen Return-path: In-Reply-To: <20080827162735.GW26610@one.firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Andi Kleen wrote: >>Those banks really want to crank down on latency - to the point they >>start disabling interrupt coalescing. I bet they'd toss anything out >>they could to shave another microsecond. > > > This change would actually likely lower their latency. I'm guessing you mean increase their latency? I agree, it could - depends entirely on the PPS in production I suspect. rick jones ftp://ftp.cup.hp.com/dist/networking/briefs/nic_latency_vs_tput.txt I should probably refresh/update that one of these days