From owner-freebsd-current Thu Sep 21 16:59:33 2000 Delivered-To: freebsd-current@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (Postfix) with ESMTP id C0F6537B440; Thu, 21 Sep 2000 16:59:28 -0700 (PDT) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.9.3/8.9.3) with ESMTP id RAA07515; Thu, 21 Sep 2000 17:59:25 -0600 (MDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id RAA63352; Thu, 21 Sep 2000 17:59:25 -0600 (MDT) Message-Id: <200009212359.RAA63352@harmony.village.org> To: Tony Finch Subject: Re: new idle_proc() makes my laptop very hot Cc: Mike Smith , current@FreeBSD.ORG In-reply-to: Your message of "Thu, 21 Sep 2000 23:49:45 -0000." <20000921234945.F5948@hand.dotat.at> References: <20000921234945.F5948@hand.dotat.at> <200009212303.QAA62850@mass.osd.bsdi.com> <200009212310.RAA62949@harmony.village.org> Date: Thu, 21 Sep 2000 17:59:25 -0600 From: Warner Losh Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <20000921234945.F5948@hand.dotat.at> Tony Finch writes: : Warner Losh wrote: : >Mike Smith writes: : >> : >> If I remember from a discussion with John Baldwin, the reason we : >> don't do this (yet) is that HLT only wakes up when you take an : >> interrupt, and there are cases where we can't guarantee that we'll : >> take an interrupt in order to get us out of the HLT. : > : >I thought that's what the timer interrupts were for... We can't : >guarantee that we'll get one? That seems very serious to me. : : The problem is that one cpu may wich to schedule a process to run on : the idle cpu, but it can't because the idle cpu is halted and won't : wake up until the next irq. Since I'm running a UP kernel, that can't happen. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message