[PATCH v3] drm/xe/pmu: Add GT frequency events
Lucas De Marchi
lucas.demarchi at intel.com
Tue Feb 25 17:47:12 UTC 2025
On Wed, Feb 12, 2025 at 04:02:20PM -0800, Vinay Belgaumkar wrote:
>Define PMU events for GT frequency (actual and requested). This is
>a port from the i915 driver implementation, where an internal timer
>is used to aggregate GT frequencies over certain fixed interval.
>Following PMU events are being added-
>
> xe_0000_00_02.0/gt-actual-frequency/ [Kernel PMU event]
> xe_0000_00_02.0/gt-requested-frequency/ [Kernel PMU event]
>
>Standard perf commands can be used to monitor GT frequency-
> $ perf stat -e xe_0000_00_02.0/gt-requested-frequency,gt=0/ -I1000
>
> 1.001175175 700 M xe/gt-requested-frequency,gt=0/
> 2.005891881 703 M xe/gt-requested-frequency,gt=0/
> 3.007318169 700 M xe/gt-requested-frequency,gt=0/
>
>Actual frequencies will be reported as 0 when GT is in C6.
>
>v2: Use locks while storing/reading samples, keep track of multiple
>clients (Lucas) and other general cleanup.
>
>Cc: Riana Tauro <riana.tauro at intel.com>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
>---
> drivers/gpu/drm/xe/xe_pmu.c | 211 ++++++++++++++++++++++++++++--
> drivers/gpu/drm/xe/xe_pmu_types.h | 29 ++++
> 2 files changed, 230 insertions(+), 10 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_pmu.c b/drivers/gpu/drm/xe/xe_pmu.c
>index 3910a82328ee..ed76756403ea 100644
>--- a/drivers/gpu/drm/xe/xe_pmu.c
>+++ b/drivers/gpu/drm/xe/xe_pmu.c
>@@ -8,6 +8,8 @@
>
> #include "xe_device.h"
> #include "xe_gt_idle.h"
>+#include "xe_guc_pc.h"
>+#include "xe_macros.h"
> #include "xe_pm.h"
> #include "xe_pmu.h"
>
>@@ -37,6 +39,17 @@
>
> #define XE_PMU_EVENT_GT_MASK GENMASK_ULL(63, 60)
> #define XE_PMU_EVENT_ID_MASK GENMASK_ULL(11, 0)
>+#define XE_HRTIMER_INTERVAL_NS 5000000
>+
>+static struct xe_pmu *event_to_pmu(struct perf_event *event)
>+{
>+ return container_of(event->pmu, typeof(struct xe_pmu), base);
>+}
>+
>+static struct xe_device *event_to_xe(struct perf_event *event)
>+{
>+ return container_of(event->pmu, typeof(struct xe_device), pmu.base);
>+}
we shouldn't add refactors like this in the same patch you are adding a
new feature, it creates noise in the patch and makes it harder to see
what's going on. Please drop both event_to_pmu() and event_to_xe().
>
> static unsigned int config_to_event_id(u64 config)
> {
>@@ -49,10 +62,12 @@ static unsigned int config_to_gt_id(u64 config)
> }
>
> #define XE_PMU_EVENT_GT_C6_RESIDENCY 0x01
>+#define XE_PMU_EVENT_GT_ACTUAL_FREQUENCY 0x02
>+#define XE_PMU_EVENT_GT_REQUESTED_FREQUENCY 0x03
this will need a rebase
>
> static struct xe_gt *event_to_gt(struct perf_event *event)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> u64 gt = config_to_gt_id(event->attr.config);
>
> return xe_device_get_gt(xe, gt);
>@@ -70,7 +85,7 @@ static bool event_supported(struct xe_pmu *pmu, unsigned int gt,
>
> static void xe_pmu_event_destroy(struct perf_event *event)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
>
> drm_WARN_ON(&xe->drm, event->parent);
> xe_pm_runtime_put(xe);
>@@ -79,7 +94,7 @@ static void xe_pmu_event_destroy(struct perf_event *event)
>
> static int xe_pmu_event_init(struct perf_event *event)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> struct xe_pmu *pmu = &xe->pmu;
> unsigned int id, gt;
>
>@@ -104,6 +119,8 @@ static int xe_pmu_event_init(struct perf_event *event)
> if (has_branch_stack(event))
> return -EOPNOTSUPP;
>
>+ XE_WARN_ON(id >= XE_PMU_MAX_EVENT_TYPES);
I was going to say that we don't need the other ones. But then I noticed
XE_PMU_MAX_EVENT_TYPES == 64, which is a lot more than we currently
support.
I suggested it before, but what's the issue of keeping a linked list of
the events like rapl_pmu::active_list?
>+
> if (!event->parent) {
> drm_dev_get(&xe->drm);
> xe_pm_runtime_get(xe);
>@@ -113,16 +130,50 @@ static int xe_pmu_event_init(struct perf_event *event)
> return 0;
> }
>
>+static u64
>+xe_get_pmu_sample(struct xe_pmu *pmu, unsigned int gt_id, uint32_t id)
>+{
>+ unsigned long flags;
>+ u64 val;
>+
>+ raw_spin_lock_irqsave(&pmu->lock, flags);
>+ val = pmu->event_sample[gt_id][id];
>+ raw_spin_unlock_irqrestore(&pmu->lock, flags);
>+
>+ return val;
>+}
>+
>+static void
>+xe_store_pmu_sample(struct xe_pmu *pmu, uint32_t gt_id, uint32_t id,
>+ uint32_t val, uint32_t period)
>+{
>+ unsigned long flags;
>+
>+ raw_spin_lock_irqsave(&pmu->lock, flags);
>+ pmu->event_sample[gt_id][id] += mul_u32_u32(val, period);
>+ raw_spin_unlock_irqrestore(&pmu->lock, flags);
>+}
>+
> static u64 __xe_pmu_event_read(struct perf_event *event)
> {
> struct xe_gt *gt = event_to_gt(event);
>+ struct xe_device *xe = event_to_xe(event);
gt_to_xe() avoids the additional helper and you don't even need it.
You are intested in the pmu, not xe... so you could just have used
pmu = container_of(event->pmu, typeof(struct xe_pmu), base);
... like is done in other places.
>+ struct xe_pmu *pmu = &xe->pmu;
>+ unsigned long id;
>
> if (!gt)
> return 0;
>
>- switch (config_to_event_id(event->attr.config)) {
>+ id = config_to_event_id(event->attr.config);
>+
>+ switch (id) {
> case XE_PMU_EVENT_GT_C6_RESIDENCY:
> return xe_gt_idle_residency_msec(>->gtidle);
>+ case XE_PMU_EVENT_GT_ACTUAL_FREQUENCY:
>+ case XE_PMU_EVENT_GT_REQUESTED_FREQUENCY:
>+ return div_u64(xe_get_pmu_sample(pmu, gt->info.id,
>+ id),
keep in the line above, it doesn't help readability.
>+ USEC_PER_SEC /* to MHz */);
why is the unit nsec -> usec when storing, couldn't we just use
NSEC_PER_SEC here?
> }
>
> return 0;
>@@ -143,7 +194,7 @@ static void xe_pmu_event_update(struct perf_event *event)
>
> static void xe_pmu_event_read(struct perf_event *event)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> struct xe_pmu *pmu = &xe->pmu;
>
> if (!pmu->registered) {
>@@ -154,8 +205,105 @@ static void xe_pmu_event_read(struct perf_event *event)
> xe_pmu_event_update(event);
> }
>
>+static bool gt_pmu_event_active(struct xe_pmu *pmu, uint32_t id, uint32_t gt_id)
>+{
>+ return pmu->active_mask[gt_id] & BIT_ULL(id);
>+}
>+
>+static bool pmu_needs_timer(struct xe_pmu *pmu)
>+{
>+ struct xe_device *xe = container_of(pmu, typeof(*xe), pmu);
>+ struct xe_gt *gt;
>+ int i;
>+
>+ for_each_gt(gt, xe, i)
>+ if (gt_pmu_event_active(pmu, XE_PMU_EVENT_GT_ACTUAL_FREQUENCY, i) ||
>+ gt_pmu_event_active(pmu, XE_PMU_EVENT_GT_REQUESTED_FREQUENCY, i))
>+ return true;
>+
>+ return false;
>+}
>+
>+static void xe_pmu_start_timer(struct xe_pmu *pmu, uint32_t gt_id)
>+{
>+ /* Timer is per device */
>+ if (!pmu->timer_enabled && pmu_needs_timer(pmu)) {
>+ pmu->timer_enabled = true;
>+ pmu->timer_last = ktime_get();
>+ hrtimer_start_range_ns(&pmu->timer,
>+ ns_to_ktime(XE_HRTIMER_INTERVAL_NS), 0,
>+ HRTIMER_MODE_REL_PINNED);
>+ }
>+}
>+
>+static void
>+xe_sample_gt_frequency(struct xe_gt *gt, uint32_t period_ns)
>+{
>+ struct xe_device *xe = gt_to_xe(gt);
>+ struct xe_pmu *pmu = &xe->pmu;
>+ uint32_t act_freq, cur_freq;
>+ int ret;
>+
>+ if (gt_pmu_event_active(pmu, XE_PMU_EVENT_GT_ACTUAL_FREQUENCY, gt->info.id)) {
>+
drop this line
>+ /* Actual freq will be 0 when GT is in C6 */
>+ act_freq = xe_guc_pc_get_act_freq(>->uc.guc.pc);
>+ xe_store_pmu_sample(pmu, gt->info.id, XE_PMU_EVENT_GT_ACTUAL_FREQUENCY,
>+ act_freq, period_ns / NSEC_PER_USEC);
>+ }
>+
>+ if (gt_pmu_event_active(pmu, XE_PMU_EVENT_GT_REQUESTED_FREQUENCY, gt->info.id)) {
>+ ret = xe_guc_pc_get_cur_freq(>->uc.guc.pc, &cur_freq);
>+ if (!ret)
>+ xe_store_pmu_sample(pmu, gt->info.id, XE_PMU_EVENT_GT_REQUESTED_FREQUENCY,
>+ cur_freq, period_ns / NSEC_PER_USEC);
>+ }
>+}
>+
>+static enum hrtimer_restart xe_sample(struct hrtimer *hrtimer)
>+{
>+ struct xe_pmu *pmu = container_of(hrtimer, struct xe_pmu, timer);
>+ struct xe_device *xe = container_of(pmu, typeof(*xe), pmu);
>+ u64 time_diff_ns;
>+ struct xe_gt *gt;
>+ ktime_t now;
>+ int i;
>+
>+ if (!READ_ONCE(pmu->timer_enabled))
>+ return HRTIMER_NORESTART;
>+
>+ now = ktime_get();
>+ time_diff_ns = ktime_to_ns(ktime_sub(now, pmu->timer_last));
>+ pmu->timer_last = now;
>+
>+ /*
>+ * The passed in period includes the time needed for grabbing the forcewake.
I don't think this is true anymore, is it?
xe_sample()
1. calculate time_diff at the beginning of the function
2. for each gt, readout freq samples, using the time_diff, may include
delays on forcewake, but that is not included in the time_diff
3. htimer is adjusted to timer_last + period
>+ */
>+ for_each_gt(gt, xe, i)
>+ xe_sample_gt_frequency(gt, time_diff_ns);
>+
>+ hrtimer_forward(hrtimer, now, ns_to_ktime(XE_HRTIMER_INTERVAL_NS));
>+
>+ return HRTIMER_RESTART;
>+}
>+
> static void xe_pmu_enable(struct perf_event *event)
> {
>+ struct xe_pmu *pmu = event_to_pmu(event);
>+ struct xe_gt *gt = event_to_gt(event);
>+ uint32_t id = config_to_event_id(event->attr.config);
>+ unsigned long flags;
>+
>+ raw_spin_lock_irqsave(&pmu->lock, flags);
>+
>+ /* Update event mask */
>+ pmu->active_mask[gt->info.id] |= BIT_ULL(id);
>+ pmu->n_active[gt->info.id][id]++;
>+
>+ /* Start a timer, if needed, to collect samples */
>+ xe_pmu_start_timer(pmu, gt->info.id);
>+
>+ raw_spin_unlock_irqrestore(&pmu->lock, flags);
> /*
> * Store the current counter value so we can report the correct delta
> * for all listeners. Even when the event was already enabled and has
>@@ -166,7 +314,7 @@ static void xe_pmu_enable(struct perf_event *event)
>
> static void xe_pmu_event_start(struct perf_event *event, int flags)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> struct xe_pmu *pmu = &xe->pmu;
>
> if (!pmu->registered)
>@@ -176,26 +324,53 @@ static void xe_pmu_event_start(struct perf_event *event, int flags)
> event->hw.state = 0;
> }
>
>+static void xe_pmu_disable(struct perf_event *event)
>+{
>+ struct xe_device *xe = event_to_xe(event);
>+ struct xe_pmu *pmu = &xe->pmu;
>+ unsigned long flags;
>+ uint32_t id = config_to_event_id(event->attr.config);
>+ uint32_t gt_id = config_to_gt_id(event->attr.config);
>+
>+ raw_spin_lock_irqsave(&pmu->lock, flags);
>+
>+ if (--pmu->n_active[gt_id][id] == 0) {
>+ pmu->active_mask[gt_id] &= ~BIT_ULL(id);
>+ pmu->timer_enabled &= pmu_needs_timer(pmu);
>+ }
>+
>+ raw_spin_unlock_irqrestore(&pmu->lock, flags);
>+}
>+
> static void xe_pmu_event_stop(struct perf_event *event, int flags)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> struct xe_pmu *pmu = &xe->pmu;
>+ uint32_t id = config_to_event_id(event->attr.config);
>+
>+ XE_WARN_ON(id >= XE_PMU_MAX_EVENT_TYPES);
if not using a linked list as suggested, please drop this. Instead block
the event init from succeeding.
>
>- if (pmu->registered)
>+ if (pmu->registered) {
> if (flags & PERF_EF_UPDATE)
> xe_pmu_event_update(event);
>
>+ xe_pmu_disable(event);
>+ }
>+
> event->hw.state = PERF_HES_STOPPED;
> }
>
> static int xe_pmu_event_add(struct perf_event *event, int flags)
> {
>- struct xe_device *xe = container_of(event->pmu, typeof(*xe), pmu.base);
>+ struct xe_device *xe = event_to_xe(event);
> struct xe_pmu *pmu = &xe->pmu;
>+ uint32_t id = config_to_event_id(event->attr.config);
>
> if (!pmu->registered)
> return -ENODEV;
>
>+ XE_WARN_ON(id >= XE_PMU_MAX_EVENT_TYPES);
ditto.
Lucas De Marchi
>+
> if (flags & PERF_EF_START)
> xe_pmu_event_start(event, flags);
>
>@@ -270,6 +445,10 @@ static ssize_t event_attr_show(struct device *dev,
> XE_EVENT_ATTR_GROUP(v_, id_, &pmu_event_ ##v_.attr.attr)
>
> XE_EVENT_ATTR_SIMPLE(gt-c6-residency, gt_c6_residency, XE_PMU_EVENT_GT_C6_RESIDENCY, "ms");
>+XE_EVENT_ATTR_SIMPLE(gt-actual-frequency, gt_actual_frequency,
>+ XE_PMU_EVENT_GT_ACTUAL_FREQUENCY, "Mhz");
>+XE_EVENT_ATTR_SIMPLE(gt-requested-frequency, gt_requested_frequency,
>+ XE_PMU_EVENT_GT_REQUESTED_FREQUENCY, "Mhz");
>
> static struct attribute *pmu_empty_event_attrs[] = {
> /* Empty - all events are added as groups with .attr_update() */
>@@ -283,6 +462,8 @@ static const struct attribute_group pmu_events_attr_group = {
>
> static const struct attribute_group *pmu_events_attr_update[] = {
> &pmu_group_gt_c6_residency,
>+ &pmu_group_gt_actual_frequency,
>+ &pmu_group_gt_requested_frequency,
> NULL,
> };
>
>@@ -290,8 +471,11 @@ static void set_supported_events(struct xe_pmu *pmu)
> {
> struct xe_device *xe = container_of(pmu, typeof(*xe), pmu);
>
>- if (!xe->info.skip_guc_pc)
>+ if (!xe->info.skip_guc_pc) {
> pmu->supported_events |= BIT_ULL(XE_PMU_EVENT_GT_C6_RESIDENCY);
>+ pmu->supported_events |= BIT_ULL(XE_PMU_EVENT_GT_ACTUAL_FREQUENCY);
>+ pmu->supported_events |= BIT_ULL(XE_PMU_EVENT_GT_REQUESTED_FREQUENCY);
>+ }
> }
>
> /**
>@@ -306,6 +490,8 @@ static void xe_pmu_unregister(void *arg)
> if (!pmu->registered)
> return;
>
>+ hrtimer_cancel(&pmu->timer);
>+
> pmu->registered = false;
>
> perf_pmu_unregister(&pmu->base);
>@@ -334,6 +520,11 @@ int xe_pmu_register(struct xe_pmu *pmu)
> if (IS_SRIOV_VF(xe))
> return 0;
>
>+ raw_spin_lock_init(&pmu->lock);
>+
>+ hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>+ pmu->timer.function = xe_sample;
>+
> name = kasprintf(GFP_KERNEL, "xe_%s",
> dev_name(xe->drm.dev));
> if (!name)
>diff --git a/drivers/gpu/drm/xe/xe_pmu_types.h b/drivers/gpu/drm/xe/xe_pmu_types.h
>index f5ba4d56622c..cd68cba58693 100644
>--- a/drivers/gpu/drm/xe/xe_pmu_types.h
>+++ b/drivers/gpu/drm/xe/xe_pmu_types.h
>@@ -10,6 +10,7 @@
> #include <linux/spinlock_types.h>
>
> #define XE_PMU_MAX_GT 2
>+#define XE_PMU_MAX_EVENT_TYPES 64
>
> /**
> * struct xe_pmu - PMU related data per Xe device
>@@ -34,6 +35,34 @@ struct xe_pmu {
> * @supported_events: Bitmap of supported events, indexed by event id
> */
> u64 supported_events;
>+ /**
>+ * @lock: Lock protecting enable mask and sampling
>+ */
>+ raw_spinlock_t lock;
>+ /**
>+ * @active_mask: Bit representation of active events
>+ */
>+ u64 active_mask[XE_PMU_MAX_GT];
>+ /**
>+ * @n_active: Counts for the enabled events
>+ */
>+ unsigned int n_active[XE_PMU_MAX_GT][XE_PMU_MAX_EVENT_TYPES];
>+ /**
>+ * @timer: Timer for sampling GT frequency.
>+ */
>+ struct hrtimer timer;
>+ /**
>+ * @timer_last: Timestmap of the previous timer invocation.
>+ */
>+ ktime_t timer_last;
>+ /**
>+ * @timer_enabled: Should the internal sampling timer be running.
>+ */
>+ bool timer_enabled;
>+ /**
>+ * @event_sample: Store freq related counters.
>+ */
>+ u64 event_sample[XE_PMU_MAX_GT][XE_PMU_MAX_EVENT_TYPES];
> };
>
> #endif
>--
>2.38.1
>
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