From owner-freebsd-net@FreeBSD.ORG Wed Jan 9 18:08:51 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 2FCC0F42 for ; Wed, 9 Jan 2013 18:08:51 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: from nm20-vm1.bullet.mail.ne1.yahoo.com (nm20-vm1.bullet.mail.ne1.yahoo.com [98.138.91.21]) by mx1.freebsd.org (Postfix) with ESMTP id D8C4B25F for ; Wed, 9 Jan 2013 18:08:50 +0000 (UTC) Received: from [98.138.90.49] by nm20.bullet.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 18:08:44 -0000 Received: from [98.138.88.232] by tm2.bullet.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 18:08:44 -0000 Received: from [127.0.0.1] by omp1032.mail.ne1.yahoo.com with NNFMP; 09 Jan 2013 18:08:44 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 575376.84374.bm@omp1032.mail.ne1.yahoo.com Received: (qmail 67971 invoked by uid 60001); 9 Jan 2013 18:08:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1357754924; bh=F9OXQAsu4Q6DHpZzRKr7tfpk/G7e8czVbROOnsNck5k=; 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=MIms9tv2uyYyX2stau9IxIIw6kFugSrJhglHlVT/Kd/sDBVa6ZHJl6WCgiUxtgkGO9yfNC/jvdbSopFSi1R8Bra/19Nx07X/OEImAdmsBEp7ABxHtA1xqBydx9NwZ/ieZ753woI0Je5x7XpUYrNorYtrUHVUww6IecJBU6QIEes= 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=W0ZngTjMraWP5DAG4pAD/HVWs5WTAzIMLJpdLrf3IviDGltuSqfLnxFg4L5s7G6VDA7F+FA1dD2gwMNZLoZcvqYrGvS0+mAHNqVKmUWxCn3lUmBwsOkLQ6mS8mT7JGr/JL6UctwT7dpRl5NEuRVSrJYFLDWNVqVxYgfIaVfGzXY=; X-YMail-OSG: IxS35mAVM1kQPQxr2ihv5fFjmNo2wcusSXTvda0pr_MBcdL J9EEu40RqOZ3MD9zYwQJR_z5LalohPqJVhZ9RavPtdFBFodhWgfhw6ckZza. .U1zBZslS6Ox_PFdKuPbfeMY0hlUBwRAXggBGsacqed5HBt7QoCRS8z7zAAA pXokBve0V8rSoPnsAENuZffZJfw.1ztYCDzdgWv2uvzaCRRi.reFs_rqLmq9 .Kg3ldvoKzBahoTWgO.mJZ9npO2f3ElB_h9X_iKr3PfuAixK4gMvBW4WKSAD uhQl0rwCdauxkypXWUe93oblsNk3Umj__vy2QtiRBcKEeE9uFPLsY6_mjFMX G7dPUdYZt8Yn85TsxUP0eV_6mjrDong6qygZBqst7DJ8LRqx2gFtYqCNtRtM Hn1WWbw055n4WKxRWnITiQpbsB21Ovv8lUuaeS8ow30AvdfjqN4huT78VYgd Hc31EnVlZcx0h.czoCihzCCy4bOadCblJX8L7Ror7UAyT4W.MYKKPphjh4p0 .2KEzb5oDbPcSj7ME2YMZrm7sHWr.Aw-- Received: from [174.48.128.27] by web121601.mail.ne1.yahoo.com via HTTP; Wed, 09 Jan 2013 10:08:44 PST X-Rocket-MIMEInfo: 001.001, DQoNCi0tLSBPbiBUdWUsIDEvOC8xMywgTWFyayBBdGtpbnNvbiA8YXRraW45MDFAZ21haWwuY29tPiB3cm90ZToNCg0KPiBGcm9tOiBNYXJrIEF0a2luc29uIDxhdGtpbjkwMUBnbWFpbC5jb20.DQo.IFN1YmplY3Q6IFJlOiBUbyBTTVAgb3Igbm90IHRvIFNNUA0KPiBUbzogZnJlZWJzZC1uZXRAZnJlZWJzZC5vcmcNCj4gRGF0ZTogVHVlc2RheSwgSmFudWFyeSA4LCAyMDEzLCAxMToyOSBBTQ0KPiAtLS0tLUJFR0lOIFBHUCBTSUdORUQgTUVTU0FHRS0tLS0tDQo.IEhhc2g6IFNIQTENCj4gDQo.IE9uIDAxLzABMAEBAQE- X-Mailer: YahooMailClassic/15.1.2 YahooMailWebService/0.8.130.494 Message-ID: <1357754924.51744.YahooMailClassic@web121601.mail.ne1.yahoo.com> Date: Wed, 9 Jan 2013 10:08:44 -0800 (PST) From: Barney Cordoba Subject: Re: To SMP or not to SMP To: Mark Atkinson In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-net@freebsd.org 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 18:08:51 -0000 --- On Tue, 1/8/13, Mark Atkinson wrote: > From: Mark Atkinson > Subject: Re: To SMP or not to SMP > To: freebsd-net@freebsd.org > Date: Tuesday, January 8, 2013, 11:29 AM > -----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've tested the 2 schedulers on an SMP kernel with 1 core. I don't have a 1 core system to test with so I'm using an E5520 with 1 core enabled. Bridging a controlled test (curl-loader doing a web-load test with 100 users that consistently generates 870Mb/s and 77Kpps, I see the following: top -SH ULE: idle: 74.85% kernel {em1 que} 17.68% kernel {em0 que} 5.86% httpd: .49% 4BSD: idle: 70.95% kernel {em1 que} 18.07% kernel {em0 que} 4.44% httpd: .93% Note that the https is a monitor I'm running. so it appears that theres 7% of usage missing (all other apps show 0% usage). If i had to guess just looking at the numbers, it seems that 4BSD might do better with the interrupt level stuff, and not as good with user level context switching. I think they're close enough to stick with ULE so I can just use a stock kernel. One thing that bothers me is the idle sits at 100% when other tasks are registering values under light loads, so it's certainly not all that accurate. BC