From owner-freebsd-hackers@FreeBSD.ORG Sun Nov 25 21:20:43 2007 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF5E516A419; Sun, 25 Nov 2007 21:20:43 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from cauchy.math.missouri.edu (cauchy.math.missouri.edu [128.206.184.213]) by mx1.freebsd.org (Postfix) with ESMTP id 9E9D813C447; Sun, 25 Nov 2007 21:20:43 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from cauchy.math.missouri.edu (localhost [127.0.0.1]) by cauchy.math.missouri.edu (8.14.2/8.14.1) with ESMTP id lAPLKakI006778; Sun, 25 Nov 2007 15:20:36 -0600 (CST) (envelope-from stephen@math.missouri.edu) Received: from localhost (redmail@localhost) by cauchy.math.missouri.edu (8.14.2/8.14.1/Submit) with ESMTP id lAPLKapN006775; Sun, 25 Nov 2007 15:20:36 -0600 (CST) (envelope-from stephen@math.missouri.edu) X-Authentication-Warning: cauchy.math.missouri.edu: redmail owned process doing -bs Date: Sun, 25 Nov 2007 15:20:36 -0600 (CST) From: Stephen Montgomery-Smith X-X-Sender: redmail@cauchy.math.missouri.edu To: Roman Divacky In-Reply-To: <20071125211807.GA12250@freebsd.org> Message-ID: <20071125151941.I6583@cauchy.math.missouri.edu> References: <474830F9.90305@zirakzigil.org> <6eb82e0711240638g2cc1e54o1fb1321cafe8ff9f@mail.gmail.com> <1188.202.127.99.4.1195957922.squirrel@webmail.triplegate.net.id> <20071125110116.U63238@fledge.watson.org> <20071125143546.V6583@cauchy.math.missouri.edu> <20071125211807.GA12250@freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: binto , freebsd-hackers@freebsd.org, Robert Watson , Girwatson@freebsd.org Subject: Re: Before & After Under The Giant Lock X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 25 Nov 2007 21:20:44 -0000 On Sun, 25 Nov 2007, Roman Divacky wrote: > On Sun, Nov 25, 2007 at 02:41:35PM -0600, Stephen Montgomery-Smith wrote: >> >> >> On Sun, 25 Nov 2007, Robert Watson wrote: >> >>> ........................ >>> In FreeBSD 8, I expect we'll see a continued focus on both locking >>> granularity and improving opportunities for kernel parallelism by better >>> distributing workloads over CPU pools. This is important because the >>> number of cores/chip is continuing to increase dramatically, so MP >>> performance is going to be important to keep working on. That said, the >>> results to date have been extremely promising, and I anticipate that we >>> will continue to find ways to better exploit multiprocessor hardware, >>> especially in the network stack. >>> >> >> I just want to add my 2 cents, that my recent experience with FreeBSD MP >> has been extremely positive. I tend to use highly CPU bound MP programs, >> typically lots and lots of floating point operations. It used to be that >> Linux beat FreeBSD hands down - now FreeBSD seems to have a slight edge! >> Basically my program runs about twice as fast when I run two threads as >> opposed to one - I cannot see doing any better than that! > > pure computation does not need kernel operations most of the time.. ie. > multi-threading kernel wont help much ;) > Yes, I know. But something else was also done to FreeBSD, perhaps fine tuning with the scheduler, that did bring about massive improvements.