From c7ab62bfbe0e27ef452d19d88b083f01e99f13a7 Mon Sep 17 00:00:00 2001 From: Huang Rui Date: Wed, 9 Mar 2016 13:45:06 +0800 Subject: perf/x86/amd/power: Add AMD accumulated power reporting mechanism Introduce an AMD accumlated power reporting mechanism for the Family 15h, Model 60h processor that can be used to calculate the average power consumed by a processor during a measurement interval. The feature support is indicated by CPUID Fn8000_0007_EDX[12]. This feature will be implemented both in hwmon and perf. The current design provides one event to report per package/processor power consumption by counting each compute unit power value. Here the gory details of how the computation is done: * Tsample: compute unit power accumulator sample period * Tref: the PTSC counter period (PTSC: performance timestamp counter) * N: the ratio of compute unit power accumulator sample period to the PTSC period * Jmax: max compute unit accumulated power which is indicated by MSR_C001007b[MaxCpuSwPwrAcc] * Jx/Jy: compute unit accumulated power which is indicated by MSR_C001007a[CpuSwPwrAcc] * Tx/Ty: the value of performance timestamp counter which is indicated by CU_PTSC MSR_C0010280[PTSC] * PwrCPUave: CPU average power i. Determine the ratio of Tsample to Tref by executing CPUID Fn8000_0007. N = value of CPUID Fn8000_0007_ECX[CpuPwrSampleTimeRatio[15:0]]. ii. Read the full range of the cumulative energy value from the new MSR MaxCpuSwPwrAcc. Jmax = value returned. iii. At time x, software reads CpuSwPwrAcc and samples the PTSC. Jx = value read from CpuSwPwrAcc and Tx = value read from PTSC. iv. At time y, software reads CpuSwPwrAcc and samples the PTSC. Jy = value read from CpuSwPwrAcc and Ty = value read from PTSC. v. Calculate the average power consumption for a compute unit over time period (y-x). Unit of result is uWatt: if (Jy < Jx) // Rollover has occurred Jdelta = (Jy + Jmax) - Jx else Jdelta = Jy - Jx PwrCPUave = N * Jdelta * 1000 / (Ty - Tx) Simple example: root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' make -j4 CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL scripts/checksyscalls.sh CHK include/generated/compile.h SKIPPED include/generated/compile.h Building modules, stage 2. Kernel: arch/x86/boot/bzImage is ready (#40) MODPOST 4225 modules Performance counter stats for 'system wide': 183.44 mWatts power/power-pkg/ 341.837270111 seconds time elapsed root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' sleep 10 Performance counter stats for 'system wide': 0.18 mWatts power/power-pkg/ 10.012551815 seconds time elapsed Suggested-by: Peter Zijlstra Suggested-by: Ingo Molnar Suggested-by: Borislav Petkov Signed-off-by: Huang Rui Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Brian Gerst Cc: David Ahern Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Namhyung Kim Cc: Robert Richter Cc: Stephane Eranian Cc: Vince Weaver Cc: jacob.w.shin@gmail.com Link: http://lkml.kernel.org/r/1457502306-2559-1-git-send-email-ray.huang@amd.com [ Fixed the modular build. ] Signed-off-by: Ingo Molnar --- arch/x86/events/amd/power.c | 353 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 353 insertions(+) create mode 100644 arch/x86/events/amd/power.c (limited to 'arch/x86/events/amd') diff --git a/arch/x86/events/amd/power.c b/arch/x86/events/amd/power.c new file mode 100644 index 000000000000..55a3529dbf12 --- /dev/null +++ b/arch/x86/events/amd/power.c @@ -0,0 +1,353 @@ +/* + * Performance events - AMD Processor Power Reporting Mechanism + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Huang Rui + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include "../perf_event.h" + +#define MSR_F15H_CU_PWR_ACCUMULATOR 0xc001007a +#define MSR_F15H_CU_MAX_PWR_ACCUMULATOR 0xc001007b +#define MSR_F15H_PTSC 0xc0010280 + +/* Event code: LSB 8 bits, passed in attr->config any other bit is reserved. */ +#define AMD_POWER_EVENT_MASK 0xFFULL + +/* + * Accumulated power status counters. + */ +#define AMD_POWER_EVENTSEL_PKG 1 + +/* + * The ratio of compute unit power accumulator sample period to the + * PTSC period. + */ +static unsigned int cpu_pwr_sample_ratio; + +/* Maximum accumulated power of a compute unit. */ +static u64 max_cu_acc_power; + +static struct pmu pmu_class; + +/* + * Accumulated power represents the sum of each compute unit's (CU) power + * consumption. On any core of each CU we read the total accumulated power from + * MSR_F15H_CU_PWR_ACCUMULATOR. cpu_mask represents CPU bit map of all cores + * which are picked to measure the power for the CUs they belong to. + */ +static cpumask_t cpu_mask; + +static void event_update(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 prev_pwr_acc, new_pwr_acc, prev_ptsc, new_ptsc; + u64 delta, tdelta; + + prev_pwr_acc = hwc->pwr_acc; + prev_ptsc = hwc->ptsc; + rdmsrl(MSR_F15H_CU_PWR_ACCUMULATOR, new_pwr_acc); + rdmsrl(MSR_F15H_PTSC, new_ptsc); + + /* + * Calculate the CU power consumption over a time period, the unit of + * final value (delta) is micro-Watts. Then add it to the event count. + */ + if (new_pwr_acc < prev_pwr_acc) { + delta = max_cu_acc_power + new_pwr_acc; + delta -= prev_pwr_acc; + } else + delta = new_pwr_acc - prev_pwr_acc; + + delta *= cpu_pwr_sample_ratio * 1000; + tdelta = new_ptsc - prev_ptsc; + + do_div(delta, tdelta); + local64_add(delta, &event->count); +} + +static void __pmu_event_start(struct perf_event *event) +{ + if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED))) + return; + + event->hw.state = 0; + + rdmsrl(MSR_F15H_PTSC, event->hw.ptsc); + rdmsrl(MSR_F15H_CU_PWR_ACCUMULATOR, event->hw.pwr_acc); +} + +static void pmu_event_start(struct perf_event *event, int mode) +{ + __pmu_event_start(event); +} + +static void pmu_event_stop(struct perf_event *event, int mode) +{ + struct hw_perf_event *hwc = &event->hw; + + /* Mark event as deactivated and stopped. */ + if (!(hwc->state & PERF_HES_STOPPED)) + hwc->state |= PERF_HES_STOPPED; + + /* Check if software counter update is necessary. */ + if ((mode & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { + /* + * Drain the remaining delta count out of an event + * that we are disabling: + */ + event_update(event); + hwc->state |= PERF_HES_UPTODATE; + } +} + +static int pmu_event_add(struct perf_event *event, int mode) +{ + struct hw_perf_event *hwc = &event->hw; + + hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED; + + if (mode & PERF_EF_START) + __pmu_event_start(event); + + return 0; +} + +static void pmu_event_del(struct perf_event *event, int flags) +{ + pmu_event_stop(event, PERF_EF_UPDATE); +} + +static int pmu_event_init(struct perf_event *event) +{ + u64 cfg = event->attr.config & AMD_POWER_EVENT_MASK; + + /* Only look at AMD power events. */ + if (event->attr.type != pmu_class.type) + return -ENOENT; + + /* 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 || + /* no sampling */ + event->attr.sample_period) + return -EINVAL; + + if (cfg != AMD_POWER_EVENTSEL_PKG) + return -EINVAL; + + return 0; +} + +static void pmu_event_read(struct perf_event *event) +{ + event_update(event); +} + +static ssize_t +get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf) +{ + return cpumap_print_to_pagebuf(true, buf, &cpu_mask); +} + +static DEVICE_ATTR(cpumask, S_IRUGO, get_attr_cpumask, NULL); + +static struct attribute *pmu_attrs[] = { + &dev_attr_cpumask.attr, + NULL, +}; + +static struct attribute_group pmu_attr_group = { + .attrs = pmu_attrs, +}; + +/* + * Currently it only supports to report the power of each + * processor/package. + */ +EVENT_ATTR_STR(power-pkg, power_pkg, "event=0x01"); + +EVENT_ATTR_STR(power-pkg.unit, power_pkg_unit, "mWatts"); + +/* Convert the count from micro-Watts to milli-Watts. */ +EVENT_ATTR_STR(power-pkg.scale, power_pkg_scale, "1.000000e-3"); + +static struct attribute *events_attr[] = { + EVENT_PTR(power_pkg), + EVENT_PTR(power_pkg_unit), + EVENT_PTR(power_pkg_scale), + NULL, +}; + +static struct attribute_group pmu_events_group = { + .name = "events", + .attrs = events_attr, +}; + +PMU_FORMAT_ATTR(event, "config:0-7"); + +static struct attribute *formats_attr[] = { + &format_attr_event.attr, + NULL, +}; + +static struct attribute_group pmu_format_group = { + .name = "format", + .attrs = formats_attr, +}; + +static const struct attribute_group *attr_groups[] = { + &pmu_attr_group, + &pmu_format_group, + &pmu_events_group, + NULL, +}; + +static struct pmu pmu_class = { + .attr_groups = attr_groups, + /* system-wide only */ + .task_ctx_nr = perf_invalid_context, + .event_init = pmu_event_init, + .add = pmu_event_add, + .del = pmu_event_del, + .start = pmu_event_start, + .stop = pmu_event_stop, + .read = pmu_event_read, +}; + +static void power_cpu_exit(int cpu) +{ + int target; + + if (!cpumask_test_and_clear_cpu(cpu, &cpu_mask)) + return; + + /* + * Find a new CPU on the same compute unit, if was set in cpumask + * and still some CPUs on compute unit. Then migrate event and + * context to new CPU. + */ + target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu); + if (target < nr_cpumask_bits) { + cpumask_set_cpu(target, &cpu_mask); + perf_pmu_migrate_context(&pmu_class, cpu, target); + } +} + +static void power_cpu_init(int cpu) +{ + int target; + + /* + * 1) If any CPU is set at cpu_mask in the same compute unit, do + * nothing. + * 2) If no CPU is set at cpu_mask in the same compute unit, + * set current STARTING CPU. + * + * Note: if there is a CPU aside of the new one already in the + * sibling mask, then it is also in cpu_mask. + */ + target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu); + if (target >= nr_cpumask_bits) + cpumask_set_cpu(cpu, &cpu_mask); +} + +static int +power_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) +{ + unsigned int cpu = (long)hcpu; + + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DOWN_FAILED: + case CPU_STARTING: + power_cpu_init(cpu); + break; + case CPU_DOWN_PREPARE: + power_cpu_exit(cpu); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block power_cpu_notifier_nb = { + .notifier_call = power_cpu_notifier, + .priority = CPU_PRI_PERF, +}; + +static const struct x86_cpu_id cpu_match[] = { + { .vendor = X86_VENDOR_AMD, .family = 0x15 }, + {}, +}; + +static int __init amd_power_pmu_init(void) +{ + int cpu, target, ret; + + if (!x86_match_cpu(cpu_match)) + return 0; + + if (!boot_cpu_has(X86_FEATURE_ACC_POWER)) + return -ENODEV; + + cpu_pwr_sample_ratio = cpuid_ecx(0x80000007); + + if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &max_cu_acc_power)) { + pr_err("Failed to read max compute unit power accumulator MSR\n"); + return -ENODEV; + } + + cpu_notifier_register_begin(); + + /* Choose one online core of each compute unit. */ + for_each_online_cpu(cpu) { + target = cpumask_first(topology_sibling_cpumask(cpu)); + if (!cpumask_test_cpu(target, &cpu_mask)) + cpumask_set_cpu(target, &cpu_mask); + } + + ret = perf_pmu_register(&pmu_class, "power", -1); + if (WARN_ON(ret)) { + pr_warn("AMD Power PMU registration failed\n"); + goto out; + } + + __register_cpu_notifier(&power_cpu_notifier_nb); + + pr_info("AMD Power PMU detected\n"); + +out: + cpu_notifier_register_done(); + + return ret; +} +module_init(amd_power_pmu_init); + +static void __exit amd_power_pmu_exit(void) +{ + cpu_notifier_register_begin(); + __unregister_cpu_notifier(&power_cpu_notifier_nb); + cpu_notifier_register_done(); + + perf_pmu_unregister(&pmu_class); +} +module_exit(amd_power_pmu_exit); + +MODULE_AUTHOR("Huang Rui "); +MODULE_DESCRIPTION("AMD Processor Power Reporting Mechanism"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3