/* * perf_event_intel_rapl.c: support Intel RAPL energy consumption counters * Copyright (C) 2013 Google, Inc., Stephane Eranian * * Intel RAPL interface is specified in the IA-32 Manual Vol3b * section 14.7.1 (September 2013) * * RAPL provides more controls than just reporting energy consumption * however here we only expose the 3 energy consumption free running * counters (pp0, pkg, dram). * * Each of those counters increments in a power unit defined by the * RAPL_POWER_UNIT MSR. On SandyBridge, this unit is 1/(2^16) Joules * but it can vary. * * Counter to rapl events mappings: * * pp0 counter: consumption of all physical cores (power plane 0) * event: rapl_energy_cores * perf code: 0x1 * * pkg counter: consumption of the whole processor package * event: rapl_energy_pkg * perf code: 0x2 * * dram counter: consumption of the dram domain (servers only) * event: rapl_energy_dram * perf code: 0x3 * * dram counter: consumption of the builtin-gpu domain (client only) * event: rapl_energy_gpu * perf code: 0x4 * * We manage those counters as free running (read-only). They may be * use simultaneously by other tools, such as turbostat. * * The events only support system-wide mode counting. There is no * sampling support because it does not make sense and is not * supported by the RAPL hardware. * * Because we want to avoid floating-point operations in the kernel, * the events are all reported in fixed point arithmetic (32.32). * Tools must adjust the counts to convert them to Watts using * the duration of the measurement. Tools may use a function such as * ldexp(raw_count, -32); */ #include #include #include #include #include "perf_event.h" /* * RAPL energy status counters */ #define RAPL_IDX_PP0_NRG_STAT 0 /* all cores */ #define INTEL_RAPL_PP0 0x1 /* pseudo-encoding */ #define RAPL_IDX_PKG_NRG_STAT 1 /* entire package */ #define INTEL_RAPL_PKG 0x2 /* pseudo-encoding */ #define RAPL_IDX_RAM_NRG_STAT 2 /* DRAM */ #define INTEL_RAPL_RAM 0x3 /* pseudo-encoding */ #define RAPL_IDX_PP1_NRG_STAT 3 /* gpu */ #define INTEL_RAPL_PP1 0x4 /* pseudo-encoding */ /* Clients have PP0, PKG */ #define RAPL_IDX_CLN (1<config * any other bit is reserved */ #define RAPL_EVENT_MASK 0xFFULL #define DEFINE_RAPL_FORMAT_ATTR(_var, _name, _format) \ static ssize_t __rapl_##_var##_show(struct kobject *kobj, \ struct kobj_attribute *attr, \ char *page) \ { \ BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE); \ return sprintf(page, _format "\n"); \ } \ static struct kobj_attribute format_attr_##_var = \ __ATTR(_name, 0444, __rapl_##_var##_show, NULL) #define RAPL_EVENT_DESC(_name, _config) \ { \ .attr = __ATTR(_name, 0444, rapl_event_show, NULL), \ .config = _config, \ } #define RAPL_CNTR_WIDTH 32 /* 32-bit rapl counters */ struct rapl_pmu { spinlock_t lock; int hw_unit; /* 1/2^hw_unit Joule */ int n_active; /* number of active events */ struct list_head active_list; struct pmu *pmu; /* pointer to rapl_pmu_class */ ktime_t timer_interval; /* in ktime_t unit */ struct hrtimer hrtimer; }; static struct pmu rapl_pmu_class; static cpumask_t rapl_cpu_mask; static int rapl_cntr_mask; static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu); static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu_to_free); static inline u64 rapl_read_counter(struct perf_event *event) { u64 raw; rdmsrl(event->hw.event_base, raw); return raw; } static inline u64 rapl_scale(u64 v) { /* * scale delta to smallest unit (1/2^32) * users must then scale back: count * 1/(1e9*2^32) to get Joules * or use ldexp(count, -32). * Watts = Joules/Time delta */ return v << (32 - __this_cpu_read(rapl_pmu->hw_unit)); } static u64 rapl_event_update(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; u64 prev_raw_count, new_raw_count; s64 delta, sdelta; int shift = RAPL_CNTR_WIDTH; again: prev_raw_count = local64_read(&hwc->prev_count); rdmsrl(event->hw.event_base, new_raw_count); if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, new_raw_count) != prev_raw_count) { cpu_relax(); goto again; } /* * Now we have the new raw value and have updated the prev * timestamp already. We can now calculate the elapsed delta * (event-)time and add that to the generic event. * * Careful, not all hw sign-extends above the physical width * of the count. */ delta = (new_raw_count << shift) - (prev_raw_count << shift); delta >>= shift; sdelta = rapl_scale(delta); local64_add(sdelta, &event->count); return new_raw_count; } static void rapl_start_hrtimer(struct rapl_pmu *pmu) { __hrtimer_start_range_ns(&pmu->hrtimer, pmu->timer_interval, 0, HRTIMER_MODE_REL_PINNED, 0); } static void rapl_stop_hrtimer(struct rapl_pmu *pmu) { hrtimer_cancel(&pmu->hrtimer); } static enum hrtimer_restart rapl_hrtimer_handle(struct hrtimer *hrtimer) { struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu); struct perf_event *event; unsigned long flags; if (!pmu->n_active) return HRTIMER_NORESTART; spin_lock_irqsave(&pmu->lock, flags); list_for_each_entry(event, &pmu->active_list, active_entry) { rapl_event_update(event); } spin_unlock_irqrestore(&pmu->lock, flags); hrtimer_forward_now(hrtimer, pmu->timer_interval); return HRTIMER_RESTART; } static void rapl_hrtimer_init(struct rapl_pmu *pmu) { struct hrtimer *hr = &pmu->hrtimer; hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hr->function = rapl_hrtimer_handle; } static void __rapl_pmu_event_start(struct rapl_pmu *pmu, struct perf_event *event) { if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED))) return; event->hw.state = 0; list_add_tail(&event->active_entry, &pmu->active_list); local64_set(&event->hw.prev_count, rapl_read_counter(event)); pmu->n_active++; if (pmu->n_active == 1) rapl_start_hrtimer(pmu); } static void rapl_pmu_event_start(struct perf_event *event, int mode) { struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu); unsigned long flags; spin_lock_irqsave(&pmu->lock, flags); __rapl_pmu_event_start(pmu, event); spin_unlock_irqrestore(&pmu->lock, flags); } static void rapl_pmu_event_stop(struct perf_event *event, int mode) { struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu); struct hw_perf_event *hwc = &event->hw; unsigned long flags; spin_lock_irqsave(&pmu->lock, flags); /* mark event as deactivated and stopped */ if (!(hwc->state & PERF_HES_STOPPED)) { WARN_ON_ONCE(pmu->n_active <= 0); pmu->n_active--; if (pmu->n_active == 0) rapl_stop_hrtimer(pmu); list_del(&event->active_entry); WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED); hwc->state |= PERF_HES_STOPPED; } /* check if update of sw counter is necessary */ if ((mode & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { /* * Drain the remaining delta count out of a event * that we are disabling: */ rapl_event_update(event); hwc->state |= PERF_HES_UPTODATE; } spin_unlock_irqrestore(&pmu->lock, flags); } static int rapl_pmu_event_add(struct perf_event *event, int mode) { struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu); struct hw_perf_event *hwc = &event->hw; unsigned long flags; spin_lock_irqsave(&pmu->lock, flags); hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED; if (mode & PERF_EF_START) __rapl_pmu_event_start(pmu, event); spin_unlock_irqrestore(&pmu->lock, flags); return 0; } static void rapl_pmu_event_del(struct perf_event *event, int flags) { rapl_pmu_event_stop(event, PERF_EF_UPDATE); } static int rapl_pmu_event_init(struct perf_event *event) { u64 cfg = event->attr.config & RAPL_EVENT_MASK; int bit, msr, ret = 0; /* only look at RAPL events */ if (event->attr.type != rapl_pmu_class.type) return -ENOENT; /* check only supported bits are set */ if (event->attr.config & ~RAPL_EVENT_MASK) return -EINVAL; /* * check event is known (determines counter) */ switch (cfg) { case INTEL_RAPL_PP0: bit = RAPL_IDX_PP0_NRG_STAT; msr = MSR_PP0_ENERGY_STATUS; break; case INTEL_RAPL_PKG: bit = RAPL_IDX_PKG_NRG_STAT; msr = MSR_PKG_ENERGY_STATUS; break; case INTEL_RAPL_RAM: bit = RAPL_IDX_RAM_NRG_STAT; msr = MSR_DRAM_ENERGY_STATUS; break; case INTEL_RAPL_PP1: bit = RAPL_IDX_PP1_NRG_STAT; msr = MSR_PP1_ENERGY_STATUS; break; default: return -EINVAL; } /* check event supported */ if (!(rapl_cntr_mask & (1 << bit))) return -EINVAL; /* unsupported modes and filters */ if (event->attr.exclude_user || event->attr.exclude_kernel || event->attr.exclude_hv || event->attr.exclude_idle || event->attr.exclude_host || event->attr.exclude_guest || event->attr.sample_period) /* no sampling */ return -EINVAL; /* must be done before validate_group */ event->hw.event_base = msr; event->hw.config = cfg; event->hw.idx = bit; return ret; } static void rapl_pmu_event_read(struct perf_event *event) { rapl_event_update(event); } static ssize_t rapl_get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { return cpumap_print_to_pagebuf(true, buf, &rapl_cpu_mask); } static DEVICE_ATTR(cpumask, S_IRUGO, rapl_get_attr_cpumask, NULL); static struct attribute *rapl_pmu_attrs[] = { &dev_attr_cpumask.attr, NULL, }; static struct attribute_group rapl_pmu_attr_group = { .attrs = rapl_pmu_attrs, }; EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01"); EVENT_ATTR_STR(energy-pkg , rapl_pkg, "event=0x02"); EVENT_ATTR_STR(energy-ram , rapl_ram, "event=0x03"); EVENT_ATTR_STR(energy-gpu , rapl_gpu, "event=0x04"); EVENT_ATTR_STR(energy-cores.unit, rapl_cores_unit, "Joules"); EVENT_ATTR_STR(energy-pkg.unit , rapl_pkg_unit, "Joules"); EVENT_ATTR_STR(energy-ram.unit , rapl_ram_unit, "Joules"); EVENT_ATTR_STR(energy-gpu.unit , rapl_gpu_unit, "Joules"); /* * we compute in 0.23 nJ increments regardless of MSR */ EVENT_ATTR_STR(energy-cores.scale, rapl_cores_scale, "2.3283064365386962890625e-10"); EVENT_ATTR_STR(energy-pkg.scale, rapl_pkg_scale, "2.3283064365386962890625e-10"); EVENT_ATTR_STR(energy-ram.scale, rapl_ram_scale, "2.3283064365386962890625e-10"); EVENT_ATTR_STR(energy-gpu.scale, rapl_gpu_scale, "2.3283064365386962890625e-10"); static struct attribute *rapl_events_srv_attr[] = { EVENT_PTR(rapl_cores), EVENT_PTR(rapl_pkg), EVENT_PTR(rapl_ram), EVENT_PTR(rapl_cores_unit), EVENT_PTR(rapl_pkg_unit), EVENT_PTR(rapl_ram_unit), EVENT_PTR(rapl_cores_scale), EVENT_PTR(rapl_pkg_scale), EVENT_PTR(rapl_ram_scale), NULL, }; static struct attribute *rapl_events_cln_attr[] = { EVENT_PTR(rapl_cores), EVENT_PTR(rapl_pkg), EVENT_PTR(rapl_gpu), EVENT_PTR(rapl_cores_unit), EVENT_PTR(rapl_pkg_unit), EVENT_PTR(rapl_gpu_unit), EVENT_PTR(rapl_cores_scale), EVENT_PTR(rapl_pkg_scale), EVENT_PTR(rapl_gpu_scale), NULL, }; static struct attribute *rapl_events_hsw_attr[] = { EVENT_PTR(rapl_cores), EVENT_PTR(rapl_pkg), EVENT_PTR(rapl_gpu), EVENT_PTR(rapl_ram), EVENT_PTR(rapl_cores_unit), EVENT_PTR(rapl_pkg_unit), EVENT_PTR(rapl_gpu_unit), EVENT_PTR(rapl_ram_unit), EVENT_PTR(rapl_cores_scale), EVENT_PTR(rapl_pkg_scale), EVENT_PTR(rapl_gpu_scale), EVENT_PTR(rapl_ram_scale), NULL, }; static struct attribute_group rapl_pmu_events_group = { .name = "events", .attrs = NULL, /* patched at runtime */ }; DEFINE_RAPL_FORMAT_ATTR(event, event, "config:0-7"); static struct attribute *rapl_formats_attr[] = { &format_attr_event.attr, NULL, }; static struct attribute_group rapl_pmu_format_group = { .name = "format", .attrs = rapl_formats_attr, }; const struct attribute_group *rapl_attr_groups[] = { &rapl_pmu_attr_group, &rapl_pmu_format_group, &rapl_pmu_events_group, 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; /* 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); 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); /* cancel overflow polling timer for CPU */ rapl_stop_hrtimer(pmu); } 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); } 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; u64 msr_rapl_power_unit_bits; if (pmu) return 0; if (phys_id < 0) return -1; /* protect rdmsrl() to handle virtualization */ if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits)) return -1; pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu)); if (!pmu) return -1; spin_lock_init(&pmu->lock); INIT_LIST_HEAD(&pmu->active_list); /* * grab power unit as: 1/2^unit Joules * * we cache in local PMU instance */ pmu->hw_unit = (msr_rapl_power_unit_bits >> 8) & 0x1FULL; 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 (pmu->hw_unit < 32) ms = (1000 / (2 * 100)) * (1ULL << (32 - pmu->hw_unit - 1)); else ms = 2; pmu->timer_interval = ms_to_ktime(ms); 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; return 0; } static int rapl_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) { unsigned int cpu = (long)hcpu; switch (action & ~CPU_TASKS_FROZEN) { 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_ONLINE: case CPU_DEAD: rapl_cpu_kfree(cpu); break; case CPU_DOWN_PREPARE: rapl_cpu_exit(cpu); break; default: break; } return NOTIFY_OK; } static const struct x86_cpu_id rapl_cpu_match[] = { [0] = { .vendor = X86_VENDOR_INTEL, .family = 6 }, [1] = {}, }; static int __init rapl_pmu_init(void) { struct rapl_pmu *pmu; int cpu, ret; /* * check for Intel processor family 6 */ if (!x86_match_cpu(rapl_cpu_match)) return 0; /* check supported CPU */ switch (boot_cpu_data.x86_model) { case 42: /* Sandy Bridge */ case 58: /* Ivy Bridge */ rapl_cntr_mask = RAPL_IDX_CLN; rapl_pmu_events_group.attrs = rapl_events_cln_attr; break; case 60: /* Haswell */ case 69: /* Haswell-Celeron */ rapl_cntr_mask = RAPL_IDX_HSW; rapl_pmu_events_group.attrs = rapl_events_hsw_attr; break; case 45: /* Sandy Bridge-EP */ case 62: /* IvyTown */ rapl_cntr_mask = RAPL_IDX_SRV; rapl_pmu_events_group.attrs = rapl_events_srv_attr; break; default: /* unsupported */ return 0; } cpu_notifier_register_begin(); for_each_online_cpu(cpu) { ret = rapl_cpu_prepare(cpu); if (ret) goto out; rapl_cpu_init(cpu); } __perf_cpu_notifier(rapl_cpu_notifier); ret = perf_pmu_register(&rapl_pmu_class, "power", -1); if (WARN_ON(ret)) { pr_info("RAPL PMU detected, registration failed (%d), RAPL PMU disabled\n", ret); cpu_notifier_register_done(); return -1; } pmu = __this_cpu_read(rapl_pmu); pr_info("RAPL PMU detected, hw unit 2^-%d Joules," " API unit is 2^-32 Joules," " %d fixed counters" " %llu ms ovfl timer\n", pmu->hw_unit, hweight32(rapl_cntr_mask), ktime_to_ms(pmu->timer_interval)); out: cpu_notifier_register_done(); return 0; } device_initcall(rapl_pmu_init);