Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751407AbVK2X4q (ORCPT ); Tue, 29 Nov 2005 18:56:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751408AbVK2X4q (ORCPT ); Tue, 29 Nov 2005 18:56:46 -0500 Received: from ozlabs.org ([203.10.76.45]:4332 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S1751407AbVK2X4p (ORCPT ); Tue, 29 Nov 2005 18:56:45 -0500 Date: Wed, 30 Nov 2005 10:56:26 +1100 From: David Gibson To: Andi Kleen Cc: Nicholas Miell , Stephane Eranian , Ray Bryant , discuss@x86-64.org, linux-kernel@vger.kernel.org, perfctr-devel@lists.sourceforge.net Subject: Re: [Perfctr-devel] Re: Enabling RDPMC in user space by default Message-ID: <20051129235626.GC9659@localhost.localdomain> Mail-Followup-To: David Gibson , Andi Kleen , Nicholas Miell , Stephane Eranian , Ray Bryant , discuss@x86-64.org, linux-kernel@vger.kernel.org, perfctr-devel@lists.sourceforge.net References: <20051129180903.GB6611@frankl.hpl.hp.com> <20051129181344.GN19515@wotan.suse.de> <1133300591.3271.1.camel@entropy> <20051129215207.GR19515@wotan.suse.de> <1133303615.3271.12.camel@entropy> <20051129224346.GS19515@wotan.suse.de> <1133305338.3271.30.camel@entropy> <20051129231750.GU19515@wotan.suse.de> <1133306966.3271.36.camel@entropy> <20051129233920.GW19515@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051129233920.GW19515@wotan.suse.de> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 874 Lines: 21 On Wed, Nov 30, 2005 at 12:39:20AM +0100, Andi Kleen wrote: > > Well, if that's all you want them to use RDPMC 0 for, why not just make > > PMCs programmable from userspace? > > First we need to have a cycle counter PMC anyways for the NMI watchdog. > So it can as well be used for other purposes. But the watchdog doesn't require it to be in the same place on all machines. Exporting it turns an internal requirement into an ABI point. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - 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/