Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753424Ab2KLOgm (ORCPT ); Mon, 12 Nov 2012 09:36:42 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:51461 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752254Ab2KLOgk (ORCPT ); Mon, 12 Nov 2012 09:36:40 -0500 Date: Mon, 12 Nov 2012 15:36:30 +0100 From: Robert Richter To: Stephane Eranian Cc: Jacob Shin , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Thomas Gleixner , "H. Peter Anvin" , x86 , LKML Subject: Re: [PATCH 0/4] perf, amd: Enable AMD family 15h northbridge counters Message-ID: <20121112143630.GB24433@rric.localhost> References: <1352509298-7319-1-git-send-email-jacob.shin@amd.com> <20121110115027.GC2777@rric.localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1461 Lines: 31 On 11.11.12 19:17:07, Stephane Eranian wrote: > On Sat, Nov 10, 2012 at 12:50 PM, Robert Richter wrote: > > Peter's main concerns were that my patch set is not in the > > Intel-uncore style. I started reworking this but was not able to > > finish my work. This concerns still exist. > > > That was my concern too. I don't recall exactly why it could not > be totally disconnected from the core PMU. I think hardware-wise, > it was possible. Could you refresh my memory? Current implementation only allows the use of a single x86 pmu. Multiple instances of x86 pmus in a system like an additional pmu for nb counters requires a complete rework. You need to remove global variables and extend function interfaces by arguments pointing to a struct x86_pmu. All this without adding overhead (e.g. pointer chasing) compared to the existing code. This is also the reason why the intel-uncore implemenation is basically a copy-and-paste of generic x86 pmu code plus uncore specific changes. Avoiding code cuplication and a complex rework were the reasons for simply extending the family 10h implementation to also support family 15h nb counters. This seemed to me the best approach that time. -Robert -- 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/