From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1CAFC04AB6 for ; Tue, 28 May 2019 12:05:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76F2220883 for ; Tue, 28 May 2019 12:05:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PpvBwG42" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727057AbfE1MFk (ORCPT ); Tue, 28 May 2019 08:05:40 -0400 Received: from merlin.infradead.org ([205.233.59.134]:49136 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbfE1MFk (ORCPT ); Tue, 28 May 2019 08:05:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ftNsAuf2ZIGaGmzJ8tp0H6vv9flP6yOPkxjrapmoDHQ=; b=PpvBwG42pyiuVFoap759dYsMq oj5RxxPGDtf1+0QaQRXh06yBpFdxZNByut+WFQ+uoDKdY0Gsc4xaN2qPusaYL/Fkz6ibyD4Cet7jW acci7FNmSReo3OMN4dTCjn52ykzEjfsm9EPa71Y49tekrHF2JUwLuqmCYx5i4VHOCJcMyEvVxJREG ccK9CefDEd0OC7fp0XQpWAK5OkVnUh9raEM34VPX5BITXFGkt19Dy/1+Y+w4j0TBAAJUwZ+Q5C27O 6e5fXuWdytGGe6vAqRg62rBvpTTklSmbowOxdYhEYz3KHH9fkbkVTD73SjnX3HGKx1/RBgHGeZME8 6uKseOd0g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hVarC-0003Ei-Ci; Tue, 28 May 2019 12:05:30 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 954652074C650; Tue, 28 May 2019 14:05:28 +0200 (CEST) Date: Tue, 28 May 2019 14:05:28 +0200 From: Peter Zijlstra To: kan.liang@linux.intel.com Cc: acme@kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, jolsa@kernel.org, eranian@google.com, alexander.shishkin@linux.intel.com, ak@linux.intel.com Subject: Re: [PATCH 2/9] perf/x86/intel: Basic support for metrics counters Message-ID: <20190528120528.GR2606@hirez.programming.kicks-ass.net> References: <20190521214055.31060-1-kan.liang@linux.intel.com> <20190521214055.31060-3-kan.liang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190521214055.31060-3-kan.liang@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 21, 2019 at 02:40:48PM -0700, kan.liang@linux.intel.com wrote: > From: Andi Kleen > > Metrics counters (hardware counters containing multiple metrics) > are modeled as separate registers for each TopDown metric events, > with an extra reg being used for coordinating access to the > underlying register in the scheduler. > > This patch adds the basic infrastructure to separate the scheduler > register indexes from the actual hardware register indexes. In > most cases the MSR address is already used correctly, but for > code using indexes we need a separate reg_idx field in the event > to indicate the correct underlying register. That doesn't parse. What exactly is the difference between reg_idx and idx? AFAICT there is a fixed relation like: reg_idx = is_metric_idx(idx) ? INTEL_PMC_IDX_FIXED_SLOTS : idx; Do we really need a variable for that? Also, why do we need that whole enabled_events[] array. Do we really not have that information elsewhere? I shouldn've have to reverse engineer patches :/