From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756189AbcBVWWv (ORCPT ); Mon, 22 Feb 2016 17:22:51 -0500 Received: from www.linutronix.de ([62.245.132.108]:36885 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932245AbcBVWUj (ORCPT ); Mon, 22 Feb 2016 17:20:39 -0500 Message-Id: <20160222221012.409238136@linutronix.de> User-Agent: quilt/0.63-1 Date: Mon, 22 Feb 2016 22:19:22 -0000 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , x86@kernel.org, Borislav Petkov , Stephane Eranian , Harish Chegondi , Kan Liang , Andi Kleen , Jacob Pan Subject: [patch V3 21/28] x86/perf/intel/rapl: Calculate timing once References: <20160222220733.632098221@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=x86-perf-intel-rapl--Calculate-timing-once.patch X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org No point in doing the same calculation over and over. Do it once in rapl_check_hw_unit(). Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/perf_event_intel_rapl.c | 39 ++++++++++++---------------- 1 file changed, 18 insertions(+), 21 deletions(-) Index: b/arch/x86/kernel/cpu/perf_event_intel_rapl.c =================================================================== --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -129,6 +129,7 @@ static int rapl_hw_unit[NR_RAPL_DOMAINS] static struct pmu rapl_pmu_class; static cpumask_t rapl_cpu_mask; static int rapl_cntr_mask; +static u64 rapl_timer_ms; static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu); static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu_to_free); @@ -558,7 +559,6 @@ static int rapl_cpu_prepare(int cpu) { struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu); int phys_id = topology_physical_package_id(cpu); - u64 ms; if (pmu) return 0; @@ -575,19 +575,7 @@ static int rapl_cpu_prepare(int cpu) pmu->pmu = &rapl_pmu_class; - /* - * use reference of 200W for scaling the timeout - * to avoid missing counter overflows. - * 200W = 200 Joules/sec - * divide interval by 2 to avoid lockstep (2 * 100) - * if hw unit is 32, then we use 2 ms 1/200/2 - */ - if (rapl_hw_unit[0] < 32) - ms = (1000 / (2 * 100)) * (1ULL << (32 - rapl_hw_unit[0] - 1)); - else - ms = 2; - - pmu->timer_interval = ms_to_ktime(ms); + pmu->timer_interval = ms_to_ktime(rapl_timer_ms); rapl_hrtimer_init(pmu); @@ -676,6 +664,19 @@ static int rapl_check_hw_unit(void (*qui /* Apply cpu model quirk */ if (quirk) quirk(); + + /* + * Calculate the timer rate: + * Use reference of 200W for scaling the timeout to avoid counter + * overflows. 200W = 200 Joules/sec + * Divide interval by 2 to avoid lockstep (2 * 100) + * if hw unit is 32, then we use 2 ms 1/200/2 + */ + rapl_timer_ms = 2; + if (rapl_hw_unit[0] < 32) { + rapl_timer_ms = (1000 / (2 * 100)); + rapl_timer_ms *= (1ULL << (32 - rapl_hw_unit[0] - 1)); + } return 0; } @@ -695,9 +696,7 @@ static const struct x86_cpu_id rapl_cpu_ static int __init rapl_pmu_init(void) { void (*quirk)(void) = NULL; - struct rapl_pmu *pmu; - int cpu, ret; - int i; + int cpu, ret, i; /* * check for Intel processor family 6 @@ -758,15 +757,14 @@ static int __init rapl_pmu_init(void) } __perf_cpu_notifier(rapl_cpu_notifier); - - pmu = __this_cpu_read(rapl_pmu); + cpu_notifier_register_done(); pr_info("RAPL PMU detected," " API unit is 2^-32 Joules," " %d fixed counters" " %llu ms ovfl timer\n", hweight32(rapl_cntr_mask), - ktime_to_ms(pmu->timer_interval)); + rapl_timer_ms); for (i = 0; i < NR_RAPL_DOMAINS; i++) { if (rapl_cntr_mask & (1 << i)) { pr_info("hw unit of domain %s 2^-%d Joules\n", @@ -774,7 +772,6 @@ static int __init rapl_pmu_init(void) } } - cpu_notifier_register_done(); return 0; out: