From owner-freebsd-current@FreeBSD.ORG Tue Jun 10 05:53:05 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7812637B401 for ; Tue, 10 Jun 2003 05:53:05 -0700 (PDT) Received: from prg.traveller.cz (prg.traveller.cz [193.85.2.77]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4AD8D43F75 for ; Tue, 10 Jun 2003 05:53:04 -0700 (PDT) (envelope-from mime@traveller.cz) Received: from prg.traveller.cz (localhost [127.0.0.1]) h5ACr1S0002475; Tue, 10 Jun 2003 14:53:01 +0200 (CEST) Received: from localhost (mime@localhost)id h5ACr1GI002472; Tue, 10 Jun 2003 14:53:01 +0200 (CEST) Date: Tue, 10 Jun 2003 14:53:01 +0200 (CEST) From: Michal Mertl To: Brendon and Wendy In-Reply-To: <200306092217.08270.wendy.humphrey@comcast.net> Message-ID: <20030610144351.H95203@prg.traveller.cz> References: <200306092217.08270.wendy.humphrey@comcast.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-current@freebsd.org Subject: Re: Twin CPU machine running with only one cpu? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Jun 2003 12:53:05 -0000 On Mon, 9 Jun 2003, Brendon and Wendy wrote: > Dear All, > > Just installed 5.1 RC1 on my Dual Prestonia Xeon box. Works great. In fact > this is the first time i've had much success with the 5.x branch. > > Anyway, heres my question. Despite the fact that I've recompiled my kernel > with SMP and IOAPIC enabled, I seem to have only one CPU running. At boot > time the kernel reports starting CPU#1 at the end of boot time. The machdep.* > systctls claim that I have two cpus, but no matter what I do I cannot get the > CPU load over 48% (for instance running two c programs that loop infinitely > with no delay)! > Do you mean with the subject line that you have only one physical processor installed but you expect to see two in action because of HTT? If that's the case, your behaviour is normal because HTT is by default disabled. You should be able to see an idle kthread with 'top -S' eating 100% of CPU 1. You can toggle HTT on/off at any time with 'sysctl machdep.hlt_logical_cpus=0|1'. I think that when hlt_logical_cpus == 1 system shouldn't account for logical CPUs' idle time because it's confusing to see cpu load always <= 50%. -- Michal Mertl mime@traveller.cz