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Date: Tue, 16 Apr 2024 15:58:27 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Zhang Rui <rui.zhang@...el.com>
Cc: rafael.j.wysocki@...el.com, linux-kernel@...r.kernel.org,
linux-pm@...r.kernel.org, srinivas.pandruvada@...el.com
Subject: Re: [PATCH V2 2/3] powercap: intel_rapl: Introduce APIs for PMU support
On Mon, Apr 8, 2024 at 5:52 AM Zhang Rui <rui.zhang@...el.com> wrote:
>
> Introduce two new APIs rapl_package_add_pmu()/rapl_package_remove_pmu().
>
> RAPL driver can invoke these APIs to expose its supported energy
> counters via perf PMU. The new RAPL PMU is fully compatible with current
> MSR RAPL PMU, including using the same PMU name and events
> name/id/unit/scale, etc.
>
> For example, use below command
> perf stat -e power/energy-pkg/ -e power/energy-ram/ -e power/energy-cores/ FOO
> to get the energy consumption for events in the "perf list" output.
>
> This does not introduce any conflict because TPMI RAPL is the only user
> of these APIs currently, and it never co-exists with MSR RAPL.
>
> Note that, TPMI RAPL is probed dynamically, and the events supported by
> each TPMI RAPL device can be different. Thus, for a new RAPL Package
> device that wants PMU support,
> 1. if PMU has not been registered yet, register the PMU with events
> supported by current RAPL Package device
> 2. if PMU has been registered and no new events support is needed, do
> nothing
> 2. or else, unregister current PMU and re-register the PMU with events
> supported by all probed RAPL Package devices that need PMU support.
> For example, on a dual-package system using TPMI RAPL, it is possible
> that Package 1 behaves as TPMI domain root and supports Psys domain.
> In this case, register PMU without Psys event when probing Package 0,
> and re-register the PMU with Psys event when probing Package 1.
>
> Signed-off-by: Zhang Rui <rui.zhang@...el.com>
> ---
> drivers/powercap/intel_rapl_common.c | 537 +++++++++++++++++++++++++++
> include/linux/intel_rapl.h | 23 ++
> 2 files changed, 560 insertions(+)
>
> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
> index 1f4a7aa12d77..f51012f023b0 100644
> --- a/drivers/powercap/intel_rapl_common.c
> +++ b/drivers/powercap/intel_rapl_common.c
> @@ -15,6 +15,8 @@
> #include <linux/list.h>
> #include <linux/log2.h>
> #include <linux/module.h>
> +#include <linux/nospec.h>
> +#include <linux/perf_event.h>
> #include <linux/platform_device.h>
> #include <linux/powercap.h>
> #include <linux/processor.h>
> @@ -1506,6 +1508,541 @@ static int rapl_detect_domains(struct rapl_package *rp)
> return 0;
> }
>
> +#ifdef CONFIG_PERF_EVENTS
> +
> +/* Support for RAPL PMU */
It would be good to add some details regarding the implementation etc.
to this comment.
> +
> +struct rapl_pmu {
> + struct pmu pmu;
> + u64 timer_ms;
> + cpumask_t cpu_mask;
> + unsigned long domain_map; /* Events supported by all registered RAPL packages */
> + bool registered;
> +};
The structure fields need to be documented.
> +
> +static struct rapl_pmu rapl_pmu;
> +
> +/* PMU helpers */
A blank like here?
> +static int get_pmu_cpu(struct rapl_package *rp)
> +{
> + int cpu;
> +
> + if (!rp->has_pmu)
> + return nr_cpu_ids;
> +
> + if (rp->lead_cpu >= 0)
> + return rp->lead_cpu;
> +
> + /* TPMI RAPL uses any CPU in the package for PMU */
> + for_each_online_cpu(cpu)
> + if (topology_physical_package_id(cpu) == rp->id)
> + return cpu;
> +
> + return nr_cpu_ids;
> +}
> +
> +static bool is_rp_pmu_cpu(struct rapl_package *rp, int cpu)
> +{
> + if (!rp->has_pmu)
> + return false;
> +
> + if (rp->lead_cpu >= 0)
> + return cpu == rp->lead_cpu;
So if the given CPU is not the lead CPU, but it is located in the same
package as the lead CPU, the function will return 'false'. TBH, this
is somewhat confusing.
> +
> + /* TPMI RAPL uses any CPU in the package for PMU */
> + return topology_physical_package_id(cpu) == rp->id;
> +}
> +
> +static struct rapl_package_pmu_data *event_to_pmu_data(struct perf_event *event)
> +{
> + struct rapl_package *rp = event->pmu_private;
> +
> + return &rp->pmu_data;
> +}
> +
> +/* PMU event callbacks */
> +
> +/* Return 0 for unsupported events or failed read */
Can you put this comment into the function body?
> +static u64 event_read_counter(struct perf_event *event)
> +{
> + struct rapl_package *rp = event->pmu_private;
> + u64 val;
> + int ret;
> +
> + if (event->hw.idx < 0)
> + return 0;
> +
> + ret = rapl_read_data_raw(&rp->domains[event->hw.idx], ENERGY_COUNTER, false, &val);
> + return ret ? 0 : val;
I would prefer
if (ret)
return 0;
return val;
> +}
> +
> +static void __rapl_pmu_event_start(struct perf_event *event)
> +{
> + struct rapl_package_pmu_data *data = event_to_pmu_data(event);
> +
> + if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
> + return;
> +
> + event->hw.state = 0;
> +
> + list_add_tail(&event->active_entry, &data->active_list);
> +
> + local64_set(&event->hw.prev_count, event_read_counter(event));
> + if (++data->n_active == 1)
> + hrtimer_start(&data->hrtimer, data->timer_interval,
> + HRTIMER_MODE_REL_PINNED);
> +}
> +
> +static void rapl_pmu_event_start(struct perf_event *event, int mode)
> +{
> + struct rapl_package_pmu_data *data = event_to_pmu_data(event);
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&data->lock, flags);
> + __rapl_pmu_event_start(event);
> + raw_spin_unlock_irqrestore(&data->lock, flags);
Why does it need to be raw_spin_lock_?
What exactly is protected by data->lock?
> +}
> +
> +static u64 rapl_event_update(struct perf_event *event)
> +{
> + struct hw_perf_event *hwc = &event->hw;
> + struct rapl_package_pmu_data *data = event_to_pmu_data(event);
> + u64 prev_raw_count, new_raw_count;
> + s64 delta, sdelta;
> +
> +again:
> + prev_raw_count = local64_read(&hwc->prev_count);
> + new_raw_count = event_read_counter(event);
> +
> + if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
> + new_raw_count) != prev_raw_count)
> + goto again;
It would be somewhat easier to follow if an additional u64 variable were used:
do {
prev_raw_count = local64_read(&hwc->prev_count);
new_raw_count = event_read_counter(event);
tmp = (local64_cmpxchg(&hwc->prev_count, prev_raw_count, new_raw_count);
} while (tmp != prev_raw_count);
> +
> + /*
> + * 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.
> + */
> + delta = new_raw_count - prev_raw_count;
> +
> + /*
> + * Scale delta to smallest unit (2^-32)
> + * users must then scale back: count * 1/(1e9*2^32) to get Joules
> + * or use ldexp(count, -32).
> + * Watts = Joules/Time delta
> + */
> + sdelta = delta * data->scale[event->hw.flags];
> +
> + local64_add(sdelta, &event->count);
> +
> + return new_raw_count;
> +}
> +
> +static void rapl_pmu_event_stop(struct perf_event *event, int mode)
> +{
> + struct rapl_package_pmu_data *data = event_to_pmu_data(event);
> + struct hw_perf_event *hwc = &event->hw;
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&data->lock, flags);
> +
> + /* Mark event as deactivated and stopped */
> + if (!(hwc->state & PERF_HES_STOPPED)) {
> + WARN_ON_ONCE(data->n_active <= 0);
> + if (--data->n_active == 0)
> + hrtimer_cancel(&data->hrtimer);
> +
> + 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;
> + }
> +
> + raw_spin_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +static int rapl_pmu_event_add(struct perf_event *event, int mode)
> +{
> + struct rapl_package_pmu_data *data = event_to_pmu_data(event);
> + struct hw_perf_event *hwc = &event->hw;
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&data->lock, flags);
> +
> + hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
> +
> + if (mode & PERF_EF_START)
> + __rapl_pmu_event_start(event);
> +
> + raw_spin_unlock_irqrestore(&data->lock, flags);
> +
> + return 0;
> +}
> +
> +static void rapl_pmu_event_del(struct perf_event *event, int flags)
> +{
> + rapl_pmu_event_stop(event, PERF_EF_UPDATE);
> +}
> +
> +/*
> + * RAPL energy status counters
> + */
> +enum perf_rapl_events {
> + PERF_RAPL_PP0 = 0, /* all cores */
> + PERF_RAPL_PKG, /* entire package */
> + PERF_RAPL_RAM, /* DRAM */
> + PERF_RAPL_PP1, /* gpu */
> + PERF_RAPL_PSYS, /* psys */
> +};
> +#define RAPL_EVENT_MASK GENMASK(7, 0)
> +
> +static int event_to_domain(int event)
> +{
> + switch (event) {
> + case PERF_RAPL_PP0:
> + return RAPL_DOMAIN_PP0;
> + case PERF_RAPL_PKG:
> + return RAPL_DOMAIN_PACKAGE;
> + case PERF_RAPL_RAM:
> + return RAPL_DOMAIN_DRAM;
> + case PERF_RAPL_PP1:
> + return RAPL_DOMAIN_PP1;
> + case PERF_RAPL_PSYS:
> + return RAPL_DOMAIN_PLATFORM;
> + default:
> + return RAPL_DOMAIN_MAX;
> + }
> +}
IMV it would be somewhat cleaner to use an array instead of this
wrapper around switch ().
> +
> +static int rapl_pmu_event_init(struct perf_event *event)
> +{
> + struct rapl_package *pos, *rp = NULL;
> + u64 cfg = event->attr.config & RAPL_EVENT_MASK;
> + int domain, idx;
> +
> + /* Only look at RAPL events */
> + if (event->attr.type != event->pmu->type)
> + return -ENOENT;
> +
> + /* Check only supported bits are set */
> + if (event->attr.config & ~RAPL_EVENT_MASK)
> + return -EINVAL;
> +
> + if (event->cpu < 0)
> + return -EINVAL;
> +
> + /* Find out which Package the event belongs to */
> + list_for_each_entry(pos, &rapl_packages, plist) {
> + if (is_rp_pmu_cpu(pos, event->cpu)) {
> + rp = pos;
> + break;
> + }
> + }
> + if (!rp)
> + return -ENODEV;
> +
> + /* Find out which RAPL Domain the event belongs to */
> + domain = event_to_domain(cfg - 1);
> + if (domain >= RAPL_DOMAIN_MAX)
> + return -EINVAL;
> +
> + event->event_caps |= PERF_EV_CAP_READ_ACTIVE_PKG;
> + event->pmu_private = rp; /* Which package */
> + event->hw.flags = domain; /* Which domain */
> +
> + event->hw.idx = -1;
> + /* Find out the index in rp->domains[] to get domain pointer */
> + for (idx = 0; idx < rp->nr_domains; idx++) {
> + if (rp->domains[idx].id == domain) {
> + event->hw.idx = idx;
> + break;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static void rapl_pmu_event_read(struct perf_event *event)
> +{
> + rapl_event_update(event);
> +}
> +
> +static enum hrtimer_restart rapl_hrtimer_handle(struct hrtimer *hrtimer)
> +{
> + struct rapl_package_pmu_data *data =
> + container_of(hrtimer, struct rapl_package_pmu_data, hrtimer);
> + struct perf_event *event;
> + unsigned long flags;
> +
> + if (!data->n_active)
> + return HRTIMER_NORESTART;
> +
> + raw_spin_lock_irqsave(&data->lock, flags);
> +
> + list_for_each_entry(event, &data->active_list, active_entry)
> + rapl_event_update(event);
> +
> + raw_spin_unlock_irqrestore(&data->lock, flags);
> +
> + hrtimer_forward_now(hrtimer, data->timer_interval);
> +
> + return HRTIMER_RESTART;
> +}
> +
> +/* PMU sysfs attributes */
> +
> +/*
> + * There are no default events, but we need to create "events" group (with
> + * empty attrs) before updating it with detected events.
> + */
> +static struct attribute *attrs_empty[] = {
> + NULL,
> +};
> +
> +static struct attribute_group pmu_events_group = {
> + .name = "events",
> + .attrs = attrs_empty,
> +};
> +
> +static ssize_t cpumask_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct rapl_package *rp;
> + int cpu;
> +
> + cpus_read_lock();
Is rapl_packages protected by this?
> + cpumask_clear(&rapl_pmu.cpu_mask);
It doesn't look like rapl_pmu.cpu_mask is used outside this function,
so why is it global?
> +
> + /* Choose a cpu for each RAPL Package */
> + list_for_each_entry(rp, &rapl_packages, plist) {
> + cpu = get_pmu_cpu(rp);
> + if (cpu < nr_cpu_ids)
> + cpumask_set_cpu(cpu, &rapl_pmu.cpu_mask);
> + }
> + cpus_read_unlock();
> +
> + return cpumap_print_to_pagebuf(true, buf, &rapl_pmu.cpu_mask);
> +}
> +
> +static DEVICE_ATTR_RO(cpumask);
> +
> +static struct attribute *pmu_cpumask_attrs[] = {
> + &dev_attr_cpumask.attr,
> + NULL
> +};
> +
> +static struct attribute_group pmu_cpumask_group = {
> + .attrs = pmu_cpumask_attrs,
> +};
> +
> +PMU_FORMAT_ATTR(event, "config:0-7");
> +static struct attribute *pmu_format_attr[] = {
> + &format_attr_event.attr,
> + NULL
> +};
> +
> +static struct attribute_group pmu_format_group = {
> + .name = "format",
> + .attrs = pmu_format_attr,
> +};
> +
> +static const struct attribute_group *pmu_attr_groups[] = {
> + &pmu_events_group,
> + &pmu_cpumask_group,
> + &pmu_format_group,
> + NULL
> +};
> +
> +#define RAPL_EVENT_ATTR_STR(_name, v, str) \
> +static struct perf_pmu_events_attr event_attr_##v = { \
> + .attr = __ATTR(_name, 0444, perf_event_sysfs_show, NULL), \
> + .event_str = str, \
> +}
> +
> +RAPL_EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01");
> +RAPL_EVENT_ATTR_STR(energy-pkg, rapl_pkg, "event=0x02");
> +RAPL_EVENT_ATTR_STR(energy-ram, rapl_ram, "event=0x03");
> +RAPL_EVENT_ATTR_STR(energy-gpu, rapl_gpu, "event=0x04");
> +RAPL_EVENT_ATTR_STR(energy-psys, rapl_psys, "event=0x05");
> +
> +RAPL_EVENT_ATTR_STR(energy-cores.unit, rapl_unit_cores, "Joules");
> +RAPL_EVENT_ATTR_STR(energy-pkg.unit, rapl_unit_pkg, "Joules");
> +RAPL_EVENT_ATTR_STR(energy-ram.unit, rapl_unit_ram, "Joules");
> +RAPL_EVENT_ATTR_STR(energy-gpu.unit, rapl_unit_gpu, "Joules");
> +RAPL_EVENT_ATTR_STR(energy-psys.unit, rapl_unit_psys, "Joules");
> +
> +RAPL_EVENT_ATTR_STR(energy-cores.scale, rapl_scale_cores, "2.3283064365386962890625e-10");
> +RAPL_EVENT_ATTR_STR(energy-pkg.scale, rapl_scale_pkg, "2.3283064365386962890625e-10");
> +RAPL_EVENT_ATTR_STR(energy-ram.scale, rapl_scale_ram, "2.3283064365386962890625e-10");
> +RAPL_EVENT_ATTR_STR(energy-gpu.scale, rapl_scale_gpu, "2.3283064365386962890625e-10");
> +RAPL_EVENT_ATTR_STR(energy-psys.scale, rapl_scale_psys, "2.3283064365386962890625e-10");
> +
> +#define RAPL_EVENT_GROUP(_name, domain) \
> +static struct attribute *pmu_attr_##_name[] = { \
> + &event_attr_rapl_##_name.attr.attr, \
> + &event_attr_rapl_unit_##_name.attr.attr, \
> + &event_attr_rapl_scale_##_name.attr.attr, \
> + NULL \
> +}; \
> +static umode_t is_visible_##_name(struct kobject *kobj, struct attribute *attr, int event) \
> +{ \
> + return rapl_pmu.domain_map & BIT(domain) ? attr->mode : 0; \
> +} \
> +static struct attribute_group pmu_group_##_name = { \
> + .name = "events", \
> + .attrs = pmu_attr_##_name, \
> + .is_visible = is_visible_##_name, \
> +}
> +
> +RAPL_EVENT_GROUP(cores, RAPL_DOMAIN_PP0);
> +RAPL_EVENT_GROUP(pkg, RAPL_DOMAIN_PACKAGE);
> +RAPL_EVENT_GROUP(ram, RAPL_DOMAIN_DRAM);
> +RAPL_EVENT_GROUP(gpu, RAPL_DOMAIN_PP1);
> +RAPL_EVENT_GROUP(psys, RAPL_DOMAIN_PLATFORM);
> +
> +static const struct attribute_group *pmu_attr_update[] = {
> + &pmu_group_cores,
> + &pmu_group_pkg,
> + &pmu_group_ram,
> + &pmu_group_gpu,
> + &pmu_group_psys,
> + NULL
> +};
> +
> +static int rapl_pmu_update(struct rapl_package *rp)
> +{
> + int ret;
> +
> + /* Return if PMU already covers all events supported by current RAPL Package */
> + if (rapl_pmu.registered && !(rp->domain_map & (~rapl_pmu.domain_map)))
> + return 0;
> +
> + /* Unregister previous registered PMU */
> + if (rapl_pmu.registered) {
> + perf_pmu_unregister(&rapl_pmu.pmu);
> + memset(&rapl_pmu.pmu, 0, sizeof(struct pmu));
> + }
> +
> + rapl_pmu.domain_map |= rp->domain_map;
> +
> + memset(&rapl_pmu.pmu, 0, sizeof(struct pmu));
> + rapl_pmu.pmu.attr_groups = pmu_attr_groups;
> + rapl_pmu.pmu.attr_update = pmu_attr_update;
> + rapl_pmu.pmu.task_ctx_nr = perf_invalid_context;
> + rapl_pmu.pmu.event_init = rapl_pmu_event_init;
> + rapl_pmu.pmu.add = rapl_pmu_event_add;
> + rapl_pmu.pmu.del = rapl_pmu_event_del;
> + rapl_pmu.pmu.start = rapl_pmu_event_start;
> + rapl_pmu.pmu.stop = rapl_pmu_event_stop;
> + rapl_pmu.pmu.read = rapl_pmu_event_read;
> + rapl_pmu.pmu.module = THIS_MODULE;
> + rapl_pmu.pmu.capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT;
> + ret = perf_pmu_register(&rapl_pmu.pmu, "power", -1);
> + if (ret)
> + pr_warn("Failed to register PMU\n");
> +
> + rapl_pmu.registered = !ret;
Why don't you set rp->has_pmu here?
> +
> + return ret;
It looks like this could be rearranged overall for more clarity:
ret = perf_pmu_register(&rapl_pmu.pmu, "power", -1);
if (ret) {
pr_warn("Failed to register PMU\n");
return ret;
}
rapl_pmu.registered = true;
rp->has_pmu = true;
return 0;
Also, the "Failed to register PMU\n" message is not particularly
useful AFAICS. It would be good to add some more context to it and
maybe make it pr_info()?
> +}
> +
> +int rapl_package_add_pmu(struct rapl_package *rp)
> +{
> + struct rapl_package_pmu_data *data = &rp->pmu_data;
> + int idx;
> + int ret;
> +
> + if (rp->has_pmu)
> + return -EEXIST;
> +
> + guard(cpus_read_lock)();
Why does this lock need to be held around the entire code below?
> +
> + for (idx = 0; idx < rp->nr_domains; idx++) {
> + struct rapl_domain *rd = &rp->domains[idx];
> + int domain = rd->id;
> + u64 val;
> +
> + if (!test_bit(domain, &rp->domain_map))
> + continue;
> +
> + /*
> + * The RAPL PMU granularity is 2^-32 Joules
> + * data->scale[]: times of 2^-32 Joules for each ENERGY COUNTER increase
> + */
> + val = rd->energy_unit * (1ULL << 32);
> + do_div(val, ENERGY_UNIT_SCALE * 1000000);
> + data->scale[domain] = val;
> +
> + if (!rapl_pmu.timer_ms) {
> + struct rapl_primitive_info *rpi = get_rpi(rp, ENERGY_COUNTER);
> +
> + /*
> + * Calculate the timer rate:
> + * Use reference of 200W for scaling the timeout to avoid counter
> + * overflows.
> + *
> + * max_count = rpi->mask >> rpi->shift + 1
> + * max_energy_pj = max_count * rd->energy_unit
> + * max_time_sec = (max_energy_pj / 1000000000) / 200w
> + *
> + * rapl_pmu.timer_ms = max_time_sec * 1000 / 2
> + */
> + val = (rpi->mask >> rpi->shift) + 1;
> + val *= rd->energy_unit;
> + do_div(val, 1000000 * 200 * 2);
> + rapl_pmu.timer_ms = val;
> +
> + pr_info("%llu ms ovfl timer\n", rapl_pmu.timer_ms);
s/ovfl/overflow/
And use pr_debug()?
> + }
> +
> + pr_info("Domain %s: hw unit %lld * 2^-32 Joules\n", rd->name, data->scale[domain]);
pr_debug() here too?
> + }
> +
> + /* Initialize per package PMU data */
> + raw_spin_lock_init(&data->lock);
> + INIT_LIST_HEAD(&data->active_list);
> + data->timer_interval = ms_to_ktime(rapl_pmu.timer_ms);
> + hrtimer_init(&data->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> + data->hrtimer.function = rapl_hrtimer_handle;
> +
> + ret = rapl_pmu_update(rp);
> + if (!ret)
> + rp->has_pmu = true;
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(rapl_package_add_pmu);
> +
> +void rapl_package_remove_pmu(struct rapl_package *rp)
> +{
> + struct rapl_package *pos;
> +
> + if (!rp->has_pmu)
> + return;
> +
> + guard(cpus_read_lock)();
> +
> + list_for_each_entry(pos, &rapl_packages, plist) {
rp can be used for walking this list, can't it?
> + /* PMU is still needed */
> + if (pos->has_pmu)
> + return;
> + }
> +
> + perf_pmu_unregister(&rapl_pmu.pmu);
> + memset(&rapl_pmu, 0, sizeof(struct rapl_pmu));
> +}
> +EXPORT_SYMBOL_GPL(rapl_package_remove_pmu);
> +#endif
> +
> /* called from CPU hotplug notifier, hotplug lock held */
> void rapl_remove_package_cpuslocked(struct rapl_package *rp)
> {
> diff --git a/include/linux/intel_rapl.h b/include/linux/intel_rapl.h
> index f3196f82fd8a..38e43dbb3dac 100644
> --- a/include/linux/intel_rapl.h
> +++ b/include/linux/intel_rapl.h
> @@ -158,6 +158,17 @@ struct rapl_if_priv {
> void *rpi;
> };
>
> +#ifdef CONFIG_PERF_EVENTS
Structure fields below need to be documented.
> +struct rapl_package_pmu_data {
> + u64 scale[RAPL_DOMAIN_MAX];
> + raw_spinlock_t lock;
> + int n_active;
> + struct list_head active_list;
> + ktime_t timer_interval;
> + struct hrtimer hrtimer;
> +};
> +#endif
> +
> /* maximum rapl package domain name: package-%d-die-%d */
> #define PACKAGE_DOMAIN_NAME_LENGTH 30
>
> @@ -176,6 +187,10 @@ struct rapl_package {
> struct cpumask cpumask;
> char name[PACKAGE_DOMAIN_NAME_LENGTH];
> struct rapl_if_priv *priv;
> +#ifdef CONFIG_PERF_EVENTS
> + bool has_pmu;
> + struct rapl_package_pmu_data pmu_data;
> +#endif
> };
>
> struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_priv *priv,
> @@ -188,4 +203,12 @@ struct rapl_package *rapl_find_package_domain(int id, struct rapl_if_priv *priv,
> struct rapl_package *rapl_add_package(int id, struct rapl_if_priv *priv, bool id_is_cpu);
> void rapl_remove_package(struct rapl_package *rp);
>
> +#ifdef CONFIG_PERF_EVENTS
> +int rapl_package_add_pmu(struct rapl_package *rp);
> +void rapl_package_remove_pmu(struct rapl_package *rp);
> +#else
> +static inline int rapl_package_add_pmu(struct rapl_package *rp) { return 0; }
> +static inline void rapl_package_remove_pmu(struct rapl_package *rp) { }
> +#endif
> +
> #endif /* __INTEL_RAPL_H__ */
> --
Thanks!
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