Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261461AbUJYFyL (ORCPT ); Mon, 25 Oct 2004 01:54:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261502AbUJYFyL (ORCPT ); Mon, 25 Oct 2004 01:54:11 -0400 Received: from inet-mail4.oracle.com ([148.87.2.204]:50058 "EHLO inet-mail4.oracle.com") by vger.kernel.org with ESMTP id S261461AbUJYFyH (ORCPT ); Mon, 25 Oct 2004 01:54:07 -0400 Date: Sun, 24 Oct 2004 22:53:38 -0700 From: Joel Becker To: jonathan@jonmasters.org Cc: Alan Cox , Lee Revell , Linux Kernel Mailing List , Robert Love Subject: Re: How is user space notified of CPU speed changes? Message-ID: <20041025055338.GG27633@ca-server1.us.oracle.com> Mail-Followup-To: jonathan@jonmasters.org, Alan Cox , Lee Revell , Linux Kernel Mailing List , Robert Love References: <1098399709.4131.23.camel@krustophenia.net> <1098444170.19459.7.camel@localhost.localdomain> <1098508238.13176.17.camel@krustophenia.net> <1098566366.24804.8.camel@localhost.localdomain> <35fb2e590410231635616f10c9@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35fb2e590410231635616f10c9@mail.gmail.com> X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1134 Lines: 31 On Sun, Oct 24, 2004 at 12:35:46AM +0100, Jon Masters wrote: > Out of sheer interest, you said you had an example box which did this. > I've never actually seen a modern SMP setup with different cock > frequencies (even accepting it's possible) - can you give me a more > modern example? I'm sure they're out there, I've just missed it, and I > have to confess to not being aware that Linux supported this kind of > setup. I have a dual celeron with a 433 CPU and a 466 CPU in the slots. It works, as long as you don't rely on TSC synchronicity. Also, IBM x440 boxes don't sync the TSCs between each group of 4 CPUs (that is, each group of 4 is synced internally, but different from each other group of 4). Joel -- "Vote early and vote often." - Al Capone Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: joel.becker@oracle.com Phone: (650) 506-8127 - 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/