Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756609AbbHFVzn (ORCPT ); Thu, 6 Aug 2015 17:55:43 -0400 Received: from mga14.intel.com ([192.55.52.115]:17513 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753562AbbHFVzT (ORCPT ); Thu, 6 Aug 2015 17:55:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,625,1432623600"; d="scan'208";a="743717962" From: Vikas Shivappa To: vikas.shivappa@intel.com Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, tj@kernel.org, peterz@infradead.org, matt.fleming@intel.com, will.auld@intel.com, glenn.p.williamson@intel.com, kanaka.d.juvva@intel.com, vikas.shivappa@linux.intel.com Subject: [PATCH 2/9] x86/intel_rapl: Modify hot cpu notification handling Date: Thu, 6 Aug 2015 14:55:10 -0700 Message-Id: <1438898117-3692-3-git-send-email-vikas.shivappa@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1438898117-3692-1-git-send-email-vikas.shivappa@linux.intel.com> References: <1438898117-3692-1-git-send-email-vikas.shivappa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2723 Lines: 83 - In rapl_cpu_init, use the existing package<->core map instead of looping through all cpus in rapl_cpumask. - In rapl_cpu_exit, use the same mapping instead of looping all online cpus. In large systems with large number of cpus the time taken to loop may be expensive and also the time increase linearly. Signed-off-by: Vikas Shivappa --- arch/x86/kernel/cpu/perf_event_intel_rapl.c | 35 ++++++++++++++--------------- 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index 5cbd4e6..3f3fb4c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -132,6 +132,12 @@ static struct pmu rapl_pmu_class; static cpumask_t rapl_cpu_mask; static int rapl_cntr_mask; +/* + * Temporary cpumask used during hot cpu notificaiton handling. The usage + * is serialized by hot cpu locks. + */ +static cpumask_t tmp_cpumask; + static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu); static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu_to_free); @@ -523,18 +529,16 @@ static struct pmu rapl_pmu_class = { static void rapl_cpu_exit(int cpu) { struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu); - int i, phys_id = topology_physical_package_id(cpu); int target = -1; + int i; /* find a new cpu on same package */ - for_each_online_cpu(i) { - if (i == cpu) - continue; - if (phys_id == topology_physical_package_id(i)) { - target = i; - break; - } - } + cpumask_and(&tmp_cpumask, topology_core_cpumask(cpu), cpu_online_mask); + cpumask_clear_cpu(cpu, &tmp_cpumask); + i = cpumask_any(&tmp_cpumask); + if (i < nr_cpu_ids) + target = i; + /* * clear cpu from cpumask * if was set in cpumask and still some cpu on package, @@ -556,15 +560,10 @@ static void rapl_cpu_exit(int cpu) static void rapl_cpu_init(int cpu) { - int i, phys_id = topology_physical_package_id(cpu); - - /* check if phys_is is already covered */ - for_each_cpu(i, &rapl_cpu_mask) { - if (phys_id == topology_physical_package_id(i)) - return; - } - /* was not found, so add it */ - cpumask_set_cpu(cpu, &rapl_cpu_mask); + /* check if cpu's package is already covered.If not, add it.*/ + cpumask_and(&tmp_cpumask, &rapl_cpu_mask, topology_core_cpumask(cpu)); + if (cpumask_empty(&tmp_cpumask)) + cpumask_set_cpu(cpu, &rapl_cpu_mask); } static __init void rapl_hsw_server_quirk(void) -- 1.9.1 -- 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/