Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753897AbXJAPAR (ORCPT ); Mon, 1 Oct 2007 11:00:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751511AbXJAPAF (ORCPT ); Mon, 1 Oct 2007 11:00:05 -0400 Received: from www.tglx.de ([62.245.132.106]:39010 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751365AbXJAPAD (ORCPT ); Mon, 1 Oct 2007 11:00:03 -0400 Date: Mon, 1 Oct 2007 16:59:55 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: Mikhail Kshevetskiy , linux-kernel@vger.kernel.org Subject: Re: Fwd: x86_64 and AMD with C1E In-Reply-To: <20071001143225.GA19797@one.firstfloor.org> Message-ID: References: <20071001101532.025d652f@localhost> <20071001143225.GA19797@one.firstfloor.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1082 Lines: 26 On Mon, 1 Oct 2007, Andi Kleen wrote: > > There is work in progress on a patch, which allows to utilize the hpet > > timers as per cpu timers. This should solve the problem. Be patient. > > Given that e.g. ICH8 only has 3 HPET timers that seems doubtful > except for the special case of single-socket non hyper threaded dual core. > You'll probably do a lot of broadcasting and IPI'ing still. > > Also you'll likely make user space unhappy which often requires > at least one free HPET timer for /dev/rtc. Ok I suppose that > could be replaced with a hrtimer. Yes, we can replace rtc with a hrtimer. Also HPET can operate in non legacy irq mode, so the legacy rtc is still available. So if the number of hpet channels is greater/equal to the number of possible CPUs it's perfectly fine and does not need IPI at all. Thanks, tglx - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/