From owner-freebsd-current@FreeBSD.ORG Tue Jun 20 17:15:44 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org 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 004B716A494; Tue, 20 Jun 2006 17:15:43 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.FreeBSD.org (Postfix) with ESMTP id 791C943D73; Tue, 20 Jun 2006 17:15:41 +0000 (GMT) (envelope-from avg@icyb.net.ua) Received: from [212.40.38.87] (oddity-e.topspin.kiev.ua [212.40.38.87]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id UAA10845; Tue, 20 Jun 2006 20:15:39 +0300 (EEST) (envelope-from avg@icyb.net.ua) Message-ID: <44982D3B.9050409@icyb.net.ua> Date: Tue, 20 Jun 2006 20:15:39 +0300 From: Andriy Gapon User-Agent: Thunderbird 1.5.0.4 (X11/20060615) MIME-Version: 1.0 To: freebsd-current@freebsd.org References: <1148837064.00534930.1148826605@10.7.7.3> <200606011504.31635.jhb@freebsd.org> <44929864.4080207@icyb.net.ua> <200606161509.28998.jhb@freebsd.org> <4497F3DE.7030000@icyb.net.ua> In-Reply-To: <4497F3DE.7030000@icyb.net.ua> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Nate Lawson Subject: Re: Freeze due to performance_cx_lowest=LOW X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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, 20 Jun 2006 17:15:44 -0000 on 20/06/2006 16:10 Andriy Gapon said the following: > Well, I think MP systems are "meant" to use lapic timer; anyway, I do > not care much for them now :-) But I am exploring possibilities to avoid > using lapic timer (or to augment it) on UP systems. And, as you confirm, > RTC seems to be a good candidate for that. > BTW, an interesting link here: http://www.microsoft.com/whdc/system/CEC/mm-timer.mspx Some quotes: 8254 PIT ... this timer is only used in periodic mode to provide the periodic clock interrupt on uni-processor systems. [in Windows] RTC ... The RTC is used in periodic mode to provide the system profiling interrupt on uni-processor systems and the clock interrupt on multi-processor systems. [in Windows] Not sure about their terminology and how up-to-date this document is, but I think that they use 8254 for hardclock on non-APIC systems and RTC on APIC systems in Windows XP. -- Andriy Gapon