Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755949AbaDXKiC (ORCPT ); Thu, 24 Apr 2014 06:38:02 -0400 Received: from mga09.intel.com ([134.134.136.24]:40390 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754234AbaDXKh5 (ORCPT ); Thu, 24 Apr 2014 06:37:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,918,1389772800"; d="scan'208";a="498805096" Message-ID: <5358E982.4030106@intel.com> Date: Thu, 24 Apr 2014 18:37:54 +0800 From: "Yan, Zheng" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Stephane Eranian CC: Ingo Molnar , LKML , Peter Zijlstra , Arnaldo Carvalho de Melo , Andi Kleen Subject: Re: [PATCH v2 4/4] perf/x86/uncore: modularize Intel uncore driver References: <1395295426-12391-1-git-send-email-zheng.z.yan@intel.com> <20140418105354.GA29167@gmail.com> <53548008.3040504@intel.com> <20140422113545.GA14950@gmail.com> <20140424081408.GA7709@gmail.com> <5358E6A2.3020505@intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/24/2014 06:36 PM, Stephane Eranian wrote: > On Thu, Apr 24, 2014 at 12:25 PM, Yan, Zheng wrote: >> On 04/24/2014 04:14 PM, Ingo Molnar wrote: >>> >>> * Stephane Eranian wrote: >>> >>>>>> Most of the codes without comments are hardware specific codes. >>>>>> The corresponding contents in Intel uncore documents are big >>>>>> tables/lists, nothing tricky/interesting. I really don't know how >>>>>> to comment these code. >>>>> >>>>> Have a look at other PMU drivers, such as >>>>> arch/x86/kernel/cpu/perf_event_intel_rapl.c, which begin with a >>>>> general explanation attached below. >>>> >>>> I think a more useful modularization would be to split that huge >>>> file (perf_event_intel_uncore.c) into smaller files like we do for >>>> the core PMU. There is just too much stuff in this file for my own >>>> taste. Hard to navigate and I spend quite some time looking at it >>>> and modifying it! >>>> >>>> You could follow the model of the core PMU support files. >>>> You'd have a "core" file with the common routines, and then >>>> a file perf processor: >>>> - perf_event_intel_uncore.c >>>> - perf_event_intel_snbep_uncore.c >>>> - perf_event_intel_nhmex_uncore.c >>>> - perf_event_intel_ivt_uncore.c >>>> - ... >>>> >>>> Each processor specific module, would be a kernel module. The core >>>> could be one too. Note that this would not alleviate the need for >>>> some basic descriptions at the beginning of each file outlining the >>>> PMU boxes exported to a minimum. >> >> Most of hardware specific codes in the Intel uncore driver are for SandyBridge/IvyBridge/Haswell. Uncore subsystem in these CPUs are similar. One module per CPU type means we have to duplicate lots of code. I don't think it's a good idea. >> > Then, at least split nhm_ex from the rest. It is very big. Ok, will do. Regards Yan, Zheng >> >>> >>> This structure you outline sounds like a good first step, I like it. >>> >>> To simplify this restructuring, initially we could even keep the core >>> uncore bits in the core (ha!), to not have module-on-module >>> dependencies. >>> >>> Thanks, >>> >>> Ingo >>> >> -- 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/