From owner-freebsd-hackers@FreeBSD.ORG Sat Dec 16 20:47:02 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 1FEBA16A47B for ; Sat, 16 Dec 2006 20:47:02 +0000 (UTC) (envelope-from thorpflyer@yahoo.com) Received: from web60917.mail.yahoo.com (web60917.mail.yahoo.com [209.73.178.245]) by mx1.FreeBSD.org (Postfix) with SMTP id 9290B43C9F for ; Sat, 16 Dec 2006 20:47:01 +0000 (GMT) (envelope-from thorpflyer@yahoo.com) Received: (qmail 9756 invoked by uid 60001); 16 Dec 2006 20:47:01 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=1RHjxsmaP6CL1B0va5W1PcJS83JKyTwhDWXZ160FBFhH3TLqrJtDsYpSeQwuDfM4WMnS7pIizuanbmoPE1+IcTd/Jg3EvcPMIYOBd7lcRuYzpvrwsLjVWJCxFMU5k/5ug32o0adiEDRR4cr0xiciWmtyN2nmTiyxVDNfhG2zDRk= ; Message-ID: <20061216204701.9754.qmail@web60917.mail.yahoo.com> Received: from [67.166.15.143] by web60917.mail.yahoo.com via HTTP; Sat, 16 Dec 2006 12:47:00 PST Date: Sat, 16 Dec 2006 12:47:00 -0800 (PST) From: Simon Roberts To: freebsd-hackers@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Content-Transfer-Encoding: quoted-printable Subject: Re: "Syncing cpus" on a multi-cpu, dual core system 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: Sat, 16 Dec 2006 20:47:02 -0000 =0A----- Original Message ----=0AFrom: Stephen Montgomery-Smith =0A=0A...snip snip...=0A=0AThe other thing I have noticed i= s that when I split jobs using threads =0Aso that I can use several process= ors, the speed up to the program is far =0Aless than one might expect - ind= eed sometimes it even gets slower.=0A=0AStephen=0A=0A----------------------= ---------------------------------------------------------------------------= --------=0A=0AThis is probably Amdahl's law.=0A=0ASimon=0A=0A=0A=0A=0A=0A__= ________________________________________________=0ADo You Yahoo!?=0ATired o= f spam? Yahoo! Mail has the best spam protection around =0Ahttp://mail.yah= oo.com