From owner-freebsd-performance@FreeBSD.ORG Mon Sep 20 15:56:56 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4117E106566B for ; Mon, 20 Sep 2010 15:56:56 +0000 (UTC) (envelope-from gofp-freebsd-performance@m.gmane.org) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by mx1.freebsd.org (Postfix) with ESMTP id EEAFB8FC1E for ; Mon, 20 Sep 2010 15:56:55 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1OxiV8-00087m-IM for freebsd-performance@freebsd.org; Mon, 20 Sep 2010 17:41:54 +0200 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 20 Sep 2010 17:41:54 +0200 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 20 Sep 2010 17:41:54 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-performance@freebsd.org From: Ivan Voras Date: Mon, 20 Sep 2010 17:41:50 +0200 Lines: 26 Message-ID: References: <4C4AF046.40507@FreeBSD.org> <4C959830.3060808@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.9) Gecko/20100518 Thunderbird/3.0.4 In-Reply-To: <4C959830.3060808@FreeBSD.org> X-Enigmail-Version: 1.0.1 Subject: Re: Intel TurboBoost in practice X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Sep 2010 15:56:56 -0000 On 09/19/10 06:57, Alexander Motin wrote: > Getting back to that topic I would like to share some more results. This > time I was testing Core(TM) i7 870 @ 2.93GHz. It has 8 logical cores and > bigger allowed TurboBoost effect. I was testing real time of net/mpd5 > port building, using single CPU. I was testing it with HZ=1000 with > different C-states allowed and with/without kern.eventtimer.idletick > sysctl enabled (supported by the latest event timer code in HEAD). This > sysctl, when disabled, allows to avoid most of timer interrupts on idle > cores, allowing them to sleep deeper. If I understand correctly, TurboBoost is supposed to increase the frequency of one or a small number of cores only? What is the physical increase in frequency on this CPU when TurboBoost is enabled? > As you may see, with full timer interrupt rate TurboBoost effect (part > of it, that enabled by some number of idle cores) is about 3-4%. CPUs > are not sleeping long enough. But without extra interrupts on idle cores > effect increasing to more then 10%! Is this interpretation correct: when building with single core (-j1 effectively), using TurboBoost with the new code is >10% faster than without TurboBoost? Does it have any effect if you try using all the cores?