From owner-freebsd-net@FreeBSD.ORG Wed Jan 9 13:40:19 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id E779354D for ; Wed, 9 Jan 2013 13:40:19 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: from nm23-vm2.bullet.mail.ne1.yahoo.com (nm23-vm2.bullet.mail.ne1.yahoo.com [98.138.91.211]) by mx1.freebsd.org (Postfix) with ESMTP id 8A53FF6C for ; Wed, 9 Jan 2013 13:40:19 +0000 (UTC) Received: from [98.138.90.49] by nm23.bullet.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 13:40:13 -0000 Received: from [98.138.87.9] by tm2.bullet.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 13:40:13 -0000 Received: from [127.0.0.1] by omp1009.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 13:40:13 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 822194.68755.bm@omp1009.mail.ne1.yahoo.com Received: (qmail 53360 invoked by uid 60001); 9 Jan 2013 13:40:13 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1357738813; bh=MaO9k49rLDcWm4U3Lz+ZvtyjzZOO328CY5L3Y1w0Nqw=; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=v0cHSpeV71dHhuXJoSf6KJFQm5tdTe8uWnYQfoVad6NwIlPwisn5/tksM2UZBaQurmbUvQen1942g2DKlocJIjuKNmn6DRQtfVnJGhkWCUAhNf2rfRVXt0YaoPnpLvDU0p1u6XZV8oaORqmJUdV78Kfie3+OGeNnS9OJ7qRINFI= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=xLbePG3jdwq767v3X0K/0Ik3m6809yoT/onM4HsFnk6bhtEvqgHIOU1aV0GniGeOgAlbb2gXDEeioPswbBjzeRslgOaUub6qa9gsvvSi0+qcGv/fY0t7Fw6R7SySHq1bjPxnzBf5b76HMMyk2BseS4Ox/5mcZg3Pl8Zmrzpc4E4=; X-YMail-OSG: Lowpi7oVM1ldUsYGQ4OL.4XB8SzQwo1zZCn6og0g64_HOGt UFBohQb3Gde54uj_KyyZyKlis0eXUst_lVGZmJa4CxKFhNUSE9j.iBq56DMr 5aW2i7rdeV2Etyf58RpfRA3E_9AQr2BCxqmSyCf6D7M_xCzhQJqLPo5.wyEF Os558c0P9vFR0IfGqhp8JZD51PAb6CotZJdXK72Dp2A927fWrrKDHfoR81yg Ig61qkc0Ar1r0i6zRarUCDd799lMuIo0tuDeI7aPoqnc0NRbmltZg2L1nuZ9 Ewo.lQAuiH6axCGO81Zto35ptvpNM0oNYS_GAdvEhwLwy6doey4K5Mqnlq2m ANiqquzRJ2ztlT_dXvt42MxS7LhQh0SMBCStaCuNJI_hDcOUC8_TQwQcaCWF n1Hhb0kolYWroDCYRJw_W64dWHMpUYJN6F_x49Vx.JfeeIrXvlh_sC.botHQ ZqKn6vKKjw5y8z9bgTongTmIVd6fBB7mV5qhyE2yzKC1tIOWzITyy9Pv2H6i 1nAekNTO0VyLPps_.uk_LcUYvhypwag-- Received: from [174.48.128.27] by web121601.mail.ne1.yahoo.com via HTTP; Wed, 09 Jan 2013 05:40:13 PST X-Rocket-MIMEInfo: 001.001, CgotLS0gT24gV2VkLCAxLzkvMTMsIEVyaWNoIERvbGxhbnNreSA8ZXJpY2hzZnJlZWJzZGxpc3RAYWxvZ3QuY29tPiB3cm90ZToKCj4gRnJvbTogRXJpY2ggRG9sbGFuc2t5IDxlcmljaHNmcmVlYnNkbGlzdEBhbG9ndC5jb20.Cj4gU3ViamVjdDogUmU6IFRvIFNNUCBvciBub3QgdG8gU01QCj4gVG86ICJNYXJrIEF0a2luc29uIiA8YXRraW45MDFAZ21haWwuY29tPgo.IENjOiBmcmVlYnNkLW5ldEBmcmVlYnNkLm9yZwo.IERhdGU6IFdlZG5lc2RheSwgSmFudWFyeSA5LCAyMDEzLCAxOjAxIEFNCj4gSGksCj4BMAEBAQE- X-Mailer: YahooMailClassic/15.1.2 YahooMailWebService/0.8.130.494 Message-ID: <1357738813.28186.YahooMailClassic@web121601.mail.ne1.yahoo.com> Date: Wed, 9 Jan 2013 05:40:13 -0800 (PST) From: Barney Cordoba Subject: Re: To SMP or not to SMP To: Mark Atkinson , Erich Dollansky In-Reply-To: <20130109130133.0399a6cc@X220.ovitrap.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-net@freebsd.org, jack.vogel@gmail.com X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Jan 2013 13:40:20 -0000 --- On Wed, 1/9/13, Erich Dollansky wrote: > From: Erich Dollansky > Subject: Re: To SMP or not to SMP > To: "Mark Atkinson" > Cc: freebsd-net@freebsd.org > Date: Wednesday, January 9, 2013, 1:01 AM > Hi, > > On Tue, 08 Jan 2013 08:29:51 -0800 > Mark Atkinson > wrote: > > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > On 01/07/2013 18:25, Barney Cordoba wrote: > > > I have a situation where I have to run 9.1 on an > old single core > > > box. Does anyone have a handle on whether it's > better to build a > > > non SMP kernel or to just use a standard SMP build > with just the > > > one core? Thanks. > > > > You can build a SMP kernel, but you'll get better > performance (in my > > experience) with SCHED_4BSD on single cpu than with > ULE. > > > I would not say so. The machine behaves different with the > two > schedulers. It depends mostly what you want to do with the > machine. I > forgot which scheduler I finally left in the single CPU > kernel. > > Erich 4BSD runs pretty well with an SMP kernel. I can test ULE and compare easily. A no SMP kernel is problematic as the igb driver doesn't seem to work and my onboard NICs are, sadly, igb. Rather than say "depends what you want to do", perhaps an explanation of which cases you might choose one or the other would be helpful. So can anyone in the know confirm that the kernel really isn't smart enough to know there there's only 1 core so that most of the SMP "overhead" is avoided? It seems to me that SMP scheduling should only be enabled if there is more than 1 core as part of the scheduler initialization. Its arrogant indeed to assume that just because SMP support is compiled in that there are multiple cores. BC