From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757808AbZE2JBS (ORCPT ); Fri, 29 May 2009 05:01:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754065AbZE2JBI (ORCPT ); Fri, 29 May 2009 05:01:08 -0400 Received: from hera.kernel.org ([140.211.167.34]:59572 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753754AbZE2JBF (ORCPT ); Fri, 29 May 2009 05:01:05 -0400 Date: Fri, 29 May 2009 09:00:34 GMT From: tip-bot for Yong Wang To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, yong.y.wang@linux.intel.com, yong.y.wang@intel.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, yong.y.wang@linux.intel.com, yong.y.wang@intel.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20090529052835.GA13657@ywang-moblin2.bj.intel.com> References: <20090529052835.GA13657@ywang-moblin2.bj.intel.com> Subject: [tip:perfcounters/core] perf_counter/x86: Always use NMI for performance-monitoring interrupt Message-ID: Git-Commit-ID: c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 29 May 2009 09:00:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7 Gitweb: http://git.kernel.org/tip/c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7 Author: Yong Wang AuthorDate: Fri, 29 May 2009 13:28:35 +0800 Committer: Ingo Molnar CommitDate: Fri, 29 May 2009 09:04:58 +0200 perf_counter/x86: Always use NMI for performance-monitoring interrupt Always use NMI for performance-monitoring interrupt as there could be racy situations if we switch between irq and nmi mode frequently. Signed-off-by: Yong Wang LKML-Reference: <20090529052835.GA13657@ywang-moblin2.bj.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/perf_counter.h | 4 ++-- arch/x86/kernel/apic/apic.c | 2 +- arch/x86/kernel/cpu/perf_counter.c | 19 +++++-------------- 3 files changed, 8 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/perf_counter.h b/arch/x86/include/asm/perf_counter.h index d08dd52..876ed97 100644 --- a/arch/x86/include/asm/perf_counter.h +++ b/arch/x86/include/asm/perf_counter.h @@ -91,10 +91,10 @@ extern void set_perf_counter_pending(void); #ifdef CONFIG_PERF_COUNTERS extern void init_hw_perf_counters(void); -extern void perf_counters_lapic_init(int nmi); +extern void perf_counters_lapic_init(void); #else static inline void init_hw_perf_counters(void) { } -static inline void perf_counters_lapic_init(int nmi) { } +static inline void perf_counters_lapic_init(void) { } #endif #endif /* _ASM_X86_PERF_COUNTER_H */ diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 89b63b5..60df2ef 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1135,7 +1135,7 @@ void __cpuinit setup_local_APIC(void) apic_write(APIC_ESR, 0); } #endif - perf_counters_lapic_init(0); + perf_counters_lapic_init(); preempt_disable(); diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 2eeaa99..316b0c9 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -604,7 +604,7 @@ try_generic: hwc->counter_base = x86_pmu.perfctr; } - perf_counters_lapic_init(hwc->nmi); + perf_counters_lapic_init(); x86_pmu.disable(hwc, idx); @@ -863,24 +863,15 @@ void set_perf_counter_pending(void) apic->send_IPI_self(LOCAL_PENDING_VECTOR); } -void perf_counters_lapic_init(int nmi) +void perf_counters_lapic_init(void) { - u32 apic_val; - if (!x86_pmu_initialized()) return; /* - * Enable the performance counter vector in the APIC LVT: + * Always use NMI for PMU */ - apic_val = apic_read(APIC_LVTERR); - - apic_write(APIC_LVTERR, apic_val | APIC_LVT_MASKED); - if (nmi) - apic_write(APIC_LVTPC, APIC_DM_NMI); - else - apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR); - apic_write(APIC_LVTERR, apic_val); + apic_write(APIC_LVTPC, APIC_DM_NMI); } static int __kprobes @@ -1054,7 +1045,7 @@ void __init init_hw_perf_counters(void) pr_info("... counter mask: %016Lx\n", perf_counter_mask); - perf_counters_lapic_init(0); + perf_counters_lapic_init(); register_die_notifier(&perf_counter_nmi_notifier); }