From: Thomas Gleixner Date: Mon, 22 Feb 2016 22:19:26 +0000 (+0000) Subject: perf/x86/intel/rapl: Convert it to a per package facility X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9de8d686955b0e8e27847ed4edbbcd280f3fd853;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git perf/x86/intel/rapl: Convert it to a per package facility RAPL is a per package facility and we already have a mechanism for a dedicated per package reader. So there is no point to have multiple CPUs doing the same. The current implementation actually starts two timers on two CPUs if one does: perf stat -C1,2 -e -e power/energy-pkg .... which makes the whole concept of 1 reader per package moot. What's worse is that the above returns the double of the actual energy consumption, but that's a different problem to address and cannot be solved by removing the pointless per cpuness of that mechanism. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Cc: Andi Kleen Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Harish Chegondi Cc: Jacob Pan Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20160222221012.845369524@linutronix.de Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c index 753d90cbcce2..019e541fa988 100644 --- a/arch/x86/events/intel/rapl.c +++ b/arch/x86/events/intel/rapl.c @@ -129,15 +129,23 @@ struct rapl_pmu { struct hrtimer hrtimer; }; +struct rapl_pmus { + struct pmu pmu; + unsigned int maxpkg; + struct rapl_pmu *pmus[]; +}; + /* 1/2^hw_unit Joule */ static int rapl_hw_unit[NR_RAPL_DOMAINS] __read_mostly; -static struct pmu rapl_pmu_class; +static struct rapl_pmus *rapl_pmus; static cpumask_t rapl_cpu_mask; -static int rapl_cntr_mask; +static unsigned 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); +static inline struct rapl_pmu *cpu_to_rapl_pmu(unsigned int cpu) +{ + return rapl_pmus->pmus[topology_logical_package_id(cpu)]; +} static inline u64 rapl_read_counter(struct perf_event *event) { @@ -317,12 +325,12 @@ static void rapl_pmu_event_del(struct perf_event *event, int flags) static int rapl_pmu_event_init(struct perf_event *event) { - struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu); u64 cfg = event->attr.config & RAPL_EVENT_MASK; int bit, msr, ret = 0; + struct rapl_pmu *pmu; /* only look at RAPL events */ - if (event->attr.type != rapl_pmu_class.type) + if (event->attr.type != rapl_pmus->pmu.type) return -ENOENT; /* check only supported bits are set */ @@ -370,6 +378,7 @@ static int rapl_pmu_event_init(struct perf_event *event) return -EINVAL; /* must be done before validate_group */ + pmu = cpu_to_rapl_pmu(event->cpu); event->cpu = pmu->cpu; event->pmu_private = pmu; event->hw.event_base = msr; @@ -502,116 +511,62 @@ const struct attribute_group *rapl_attr_groups[] = { NULL, }; -static struct pmu rapl_pmu_class = { - .attr_groups = rapl_attr_groups, - .task_ctx_nr = perf_invalid_context, /* system-wide only */ - .event_init = rapl_pmu_event_init, - .add = rapl_pmu_event_add, /* must have */ - .del = rapl_pmu_event_del, /* must have */ - .start = rapl_pmu_event_start, - .stop = rapl_pmu_event_stop, - .read = rapl_pmu_event_read, -}; - 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; + struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); + int target; - /* 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; - } - } - /* - * clear cpu from cpumask - * if was set in cpumask and still some cpu on package, - * then move to new cpu - */ - if (cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask) && target >= 0) - cpumask_set_cpu(target, &rapl_cpu_mask); + /* Check if exiting cpu is used for collecting rapl events */ + if (!cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask)) + return; - WARN_ON(cpumask_empty(&rapl_cpu_mask)); - /* - * migrate events and context to new cpu - */ - if (target >= 0) - perf_pmu_migrate_context(pmu->pmu, cpu, target); + pmu->cpu = -1; + /* Find a new cpu to collect rapl events */ + target = cpumask_any_but(topology_core_cpumask(cpu), cpu); - /* cancel overflow polling timer for CPU */ - hrtimer_cancel(&pmu->hrtimer); + /* Migrate rapl events to the new target */ + if (target < nr_cpu_ids) { + cpumask_set_cpu(target, &rapl_cpu_mask); + pmu->cpu = target; + perf_pmu_migrate_context(pmu->pmu, cpu, target); + } } static void rapl_cpu_init(int cpu) { - int i, phys_id = topology_physical_package_id(cpu); + struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); + int target; + + /* + * Check if there is an online cpu in the package which collects rapl + * events already. + */ + target = cpumask_any_and(&rapl_cpu_mask, topology_core_cpumask(cpu)); + if (target < nr_cpu_ids) + return; - /* 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); + pmu->cpu = cpu; } static int rapl_cpu_prepare(int cpu) { - struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu); - int phys_id = topology_physical_package_id(cpu); + struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu); if (pmu) return 0; - if (phys_id < 0) - return -1; - pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu)); if (!pmu) - return -1; - raw_spin_lock_init(&pmu->lock); + return -ENOMEM; + raw_spin_lock_init(&pmu->lock); INIT_LIST_HEAD(&pmu->active_list); - - pmu->pmu = &rapl_pmu_class; - pmu->cpu = cpu; - + pmu->pmu = &rapl_pmus->pmu; pmu->timer_interval = ms_to_ktime(rapl_timer_ms); - + pmu->cpu = -1; rapl_hrtimer_init(pmu); - - /* set RAPL pmu for this cpu for now */ - per_cpu(rapl_pmu, cpu) = pmu; - per_cpu(rapl_pmu_to_free, cpu) = NULL; - - return 0; -} - -static void rapl_cpu_kfree(int cpu) -{ - struct rapl_pmu *pmu = per_cpu(rapl_pmu_to_free, cpu); - - kfree(pmu); - - per_cpu(rapl_pmu_to_free, cpu) = NULL; -} - -static int rapl_cpu_dying(int cpu) -{ - struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu); - - if (!pmu) - return 0; - - per_cpu(rapl_pmu, cpu) = NULL; - - per_cpu(rapl_pmu_to_free, cpu) = pmu; - + rapl_pmus->pmus[topology_logical_package_id(cpu)] = pmu; return 0; } @@ -624,24 +579,16 @@ static int rapl_cpu_notifier(struct notifier_block *self, case CPU_UP_PREPARE: rapl_cpu_prepare(cpu); break; - case CPU_STARTING: - rapl_cpu_init(cpu); - break; - case CPU_UP_CANCELED: - case CPU_DYING: - rapl_cpu_dying(cpu); - break; + + case CPU_DOWN_FAILED: case CPU_ONLINE: - case CPU_DEAD: - rapl_cpu_kfree(cpu); + rapl_cpu_init(cpu); break; + case CPU_DOWN_PREPARE: rapl_cpu_exit(cpu); break; - default: - break; } - return NOTIFY_OK; } @@ -703,10 +650,14 @@ static void __init rapl_advertise(void) static int __init rapl_prepare_cpus(void) { - unsigned int cpu; + unsigned int cpu, pkg; int ret; for_each_online_cpu(cpu) { + pkg = topology_logical_package_id(cpu); + if (rapl_pmus->pmus[pkg]) + continue; + ret = rapl_cpu_prepare(cpu); if (ret) return ret; @@ -717,10 +668,33 @@ static int __init rapl_prepare_cpus(void) static void __init cleanup_rapl_pmus(void) { - int cpu; + int i; + + for (i = 0; i < rapl_pmus->maxpkg; i++) + kfree(rapl_pmus->pmus + i); + kfree(rapl_pmus); +} - for_each_online_cpu(cpu) - kfree(per_cpu(rapl_pmu, cpu)); +static int __init init_rapl_pmus(void) +{ + int maxpkg = topology_max_packages(); + size_t size; + + size = sizeof(*rapl_pmus) + maxpkg * sizeof(struct rapl_pmu *); + rapl_pmus = kzalloc(size, GFP_KERNEL); + if (!rapl_pmus) + return -ENOMEM; + + rapl_pmus->maxpkg = maxpkg; + rapl_pmus->pmu.attr_groups = rapl_attr_groups; + rapl_pmus->pmu.task_ctx_nr = perf_invalid_context; + rapl_pmus->pmu.event_init = rapl_pmu_event_init; + rapl_pmus->pmu.add = rapl_pmu_event_add; + rapl_pmus->pmu.del = rapl_pmu_event_del; + rapl_pmus->pmu.start = rapl_pmu_event_start; + rapl_pmus->pmu.stop = rapl_pmu_event_stop; + rapl_pmus->pmu.read = rapl_pmu_event_read; + return 0; } static const struct x86_cpu_id rapl_cpu_match[] __initconst = { @@ -771,13 +745,17 @@ static int __init rapl_pmu_init(void) if (ret) return ret; + ret = init_rapl_pmus(); + if (ret) + return ret; + cpu_notifier_register_begin(); ret = rapl_prepare_cpus(); if (ret) goto out; - ret = perf_pmu_register(&rapl_pmu_class, "power", -1); + ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1); if (ret) goto out;