From owner-cvs-all Fri Jan 31 4:10:12 2003 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3D0A537B401; Fri, 31 Jan 2003 04:10:11 -0800 (PST) Received: from mailout07.sul.t-online.com (mailout07.sul.t-online.com [194.25.134.83]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1C09A43F43; Fri, 31 Jan 2003 04:10:05 -0800 (PST) (envelope-from Alexander@Leidinger.net) Received: from fwd00.sul.t-online.de by mailout07.sul.t-online.com with smtp id 18eZzd-0004qk-06; Fri, 31 Jan 2003 13:10:01 +0100 Received: from Andro-Beta.Leidinger.net (520065502893-0001@[80.131.119.242]) by fmrl00.sul.t-online.com with esmtp id 18eZzJ-1QwUmuC; Fri, 31 Jan 2003 13:09:41 +0100 Received: from Magelan.Leidinger.net (Magelan [192.168.1.1]) by Andro-Beta.Leidinger.net (8.12.6/8.12.6) with ESMTP id h0VC9ebL067443; Fri, 31 Jan 2003 13:09:40 +0100 (CET) (envelope-from Alexander@Leidinger.net) Received: from Magelan.Leidinger.net (netchild@localhost [127.0.0.1]) by Magelan.Leidinger.net (8.12.6/8.12.6) with SMTP id h0VC9dsv088392; Fri, 31 Jan 2003 13:09:39 +0100 (CET) (envelope-from Alexander@Leidinger.net) Date: Fri, 31 Jan 2003 13:09:39 +0100 From: Alexander Leidinger To: Matthew Dillon Cc: jhb@FreeBSD.org, cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/i386 mp_machdep.c Message-Id: <20030131130939.460cef5e.Alexander@Leidinger.net> In-Reply-To: <200301301952.h0UJqA0h089352@apollo.backplane.com> References: <200301301952.h0UJqA0h089352@apollo.backplane.com> X-Mailer: Sylpheed version 0.8.6claws (GTK+ 1.2.10; i386-portbld-freebsd5.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Sender: 520065502893-0001@t-dialin.net Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, 30 Jan 2003 11:52:10 -0800 (PST) Matthew Dillon wrote: > Also, I perused the linux archives a bit and they had some rather > severe scheduling issues with HTT. Apparently the logical cpus are > not equivalent to each other (?), and are definitely not as effective > as physical cpus (which makes sense), so if you have two KSEs and two > physical cpus each with an extra logical cpu, you absoultely want to > schedule the two KSEs on the two physical cpu's. The logical CPUs share the same execution units, they just have their own set of registers (this is a simplified view). Ideally you should balance KSEs with different unit usage characteristics on the same physical CPU (which is not possible to determine) because two integer intensive KSEs on the same physical CPU means that one KSE has to wait until the other KSE has finished his actual instruction (it doesn't matter if the instructions get mixed like the teeth of a zipper or not, the end-result is like scheduling the KSEs on a UP system), whereas a integer and a floating-point intensive KSE can get a performance boost when run on two logical CPUs which reside on one physical CPU. Bye, Alexander. -- Secret hacker rule #11: hackers read manuals. http://www.Leidinger.net Alexander @ Leidinger.net GPG fingerprint = C518 BC70 E67F 143F BE91 3365 79E2 9C60 B006 3FE7 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message