From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756183AbbLANl5 (ORCPT ); Tue, 1 Dec 2015 08:41:57 -0500 Received: from casper.infradead.org ([85.118.1.10]:53095 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755593AbbLANlz (ORCPT ); Tue, 1 Dec 2015 08:41:55 -0500 Date: Tue, 1 Dec 2015 14:41:51 +0100 From: Peter Zijlstra To: Andi Kleen Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, Andi Kleen Subject: Re: [PATCH 2/2] x86, perf: Use INST_RETIRED.PREC_DIST for cycles:ppp Message-ID: <20151201134151.GN3816@twins.programming.kicks-ass.net> References: <1448929689-13771-1-git-send-email-andi@firstfloor.org> <1448929689-13771-2-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448929689-13771-2-git-send-email-andi@firstfloor.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 30, 2015 at 04:28:09PM -0800, Andi Kleen wrote: > diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c > index 9dfbba5..ba41899 100644 > --- a/arch/x86/kernel/cpu/perf_event.c > +++ b/arch/x86/kernel/cpu/perf_event.c > @@ -482,6 +482,9 @@ int x86_pmu_hw_config(struct perf_event *event) > /* Support for IP fixup */ > if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2) > precise++; > + > + if (x86_pmu.pebs_aliases) > + precise++; This is not accurate, it would allow :ppp for core2 for example, which does not at all support PREC_DIST events. Something like so on top? --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -483,7 +483,7 @@ int x86_pmu_hw_config(struct perf_event if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2) precise++; - if (x86_pmu.pebs_aliases) + if (x86_pmu.pebs_prec_dist) precise++; } --- a/arch/x86/kernel/cpu/perf_event.h +++ b/arch/x86/kernel/cpu/perf_event.h @@ -593,7 +593,8 @@ struct x86_pmu { bts_active :1, pebs :1, pebs_active :1, - pebs_broken :1; + pebs_broken :1, + pebs_prec_dist :1; int pebs_record_size; void (*drain_pebs)(struct pt_regs *regs); struct event_constraint *pebs_constraints; --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -3470,6 +3470,7 @@ __init int intel_pmu_init(void) x86_pmu.event_constraints = intel_ivb_event_constraints; x86_pmu.pebs_constraints = intel_ivb_pebs_event_constraints; x86_pmu.pebs_aliases = intel_pebs_aliases_ivb; + x86_pmu.pebs_prec_dist = true; if (boot_cpu_data.x86_model == 62) x86_pmu.extra_regs = intel_snbep_extra_regs; else @@ -3503,6 +3504,7 @@ __init int intel_pmu_init(void) x86_pmu.pebs_constraints = intel_hsw_pebs_event_constraints; x86_pmu.extra_regs = intel_snbep_extra_regs; x86_pmu.pebs_aliases = intel_pebs_aliases_ivb; + x86_pmu.pebs_prec_dist = true; /* all extra regs are per-cpu when HT is on */ x86_pmu.flags |= PMU_FL_HAS_RSP_1; x86_pmu.flags |= PMU_FL_NO_HT_SHARING; @@ -3538,6 +3540,7 @@ __init int intel_pmu_init(void) x86_pmu.pebs_constraints = intel_hsw_pebs_event_constraints; x86_pmu.extra_regs = intel_snbep_extra_regs; x86_pmu.pebs_aliases = intel_pebs_aliases_ivb; + x86_pmu.pebs_prec_dist = true; /* all extra regs are per-cpu when HT is on */ x86_pmu.flags |= PMU_FL_HAS_RSP_1; x86_pmu.flags |= PMU_FL_NO_HT_SHARING; @@ -3560,6 +3563,7 @@ __init int intel_pmu_init(void) x86_pmu.pebs_constraints = intel_skl_pebs_event_constraints; x86_pmu.extra_regs = intel_skl_extra_regs; x86_pmu.pebs_aliases = intel_pebs_aliases_skl; + x86_pmu.pebs_prec_dist = true; /* all extra regs are per-cpu when HT is on */ x86_pmu.flags |= PMU_FL_HAS_RSP_1; x86_pmu.flags |= PMU_FL_NO_HT_SHARING;