From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759678AbZEFQk0 (ORCPT ); Wed, 6 May 2009 12:40:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751401AbZEFQkM (ORCPT ); Wed, 6 May 2009 12:40:12 -0400 Received: from wa4ehsobe004.messaging.microsoft.com ([216.32.181.14]:56661 "EHLO WA4EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750996AbZEFQkK (ORCPT ); Wed, 6 May 2009 12:40:10 -0400 X-BigFish: VPS-31(z34a4jz1432R62a3L98dR936eQ1805M936fJzz1202hzzz32i6bh15fn61h) X-Spam-TCS-SCL: 0:0 X-FB-SS: 5, X-WSS-ID: 0KJ8EAH-02-50N-01 Date: Wed, 6 May 2009 18:39:57 +0200 From: Robert Richter To: Andi Kleen CC: Linus Torvalds , Ingo Molnar , LKML , oprofile-list Subject: Re: [PATCH 0/2] oprofile: introduce module parameter oprofile.cpu_type Message-ID: <20090506163956.GB31757@erda.amd.com> References: <1241613554-31539-1-git-send-email-robert.richter@amd.com> <20090506144720.GQ23223@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20090506144720.GQ23223@one.firstfloor.org> User-Agent: Mutt/1.5.16 (2007-06-09) X-OriginalArrivalTime: 06 May 2009 16:39:58.0247 (UTC) FILETIME=[4B07F370:01C9CE69] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06.05.09 16:47:20, Andi Kleen wrote: > On Wed, May 06, 2009 at 02:39:12PM +0200, Robert Richter wrote: > > The current userland does not yet fully support all cpu types > > implemented in the kernel. With the module parameter oprofile.cpu_type > > a certain cpu type can be reported to the oprofile userland and thus > > makes the kernel usable with current distros. > > On Intel systems forcing archperfmon is the only one that makes sense > nd only if the CPU supports arch perfmon(btw that's already in my patchkit > which you haven't commented on so far) > > I don't thinking forcing core2 on a system like Nehalem with completely > different events is a good idea though. This just means if the user > selects anything unusual they will get junk data, which is just > a bad design. It is a kernel parameter, and users should know what they are doing and what the risks are. I assume counting cpu clk unhalted will work and some other events too. So the patch does not hurt. > Also if you force core2 on a P4 system the kernel will just oops > because it will access MSRs that are not there. So I don't think > that's a good idea. It anables core_2 only on family 6 (ppro implementation). > > It means you have to update oprofile userland at least once until > you have arch perfmon support, but I think even Linus will be able > to do that :) Hopefully Maynard will do a new release soon. I agree, a new release of the userland would be the best. But till then it is at least 1-2 months to go. > The force of core2 is nacked from my side. I do not have any passion with this patch, What I have in mind is "oprofile sucks", and this patch would make oprofile more usable. -Robert -- Advanced Micro Devices, Inc. Operating System Research Center email: robert.richter@amd.com