[PATCH v15 4/6] drm/xe/pmu: Add attribute skeleton
Riana Tauro
riana.tauro at intel.com
Thu Jan 23 15:02:39 UTC 2025
On 1/23/2025 8:18 PM, Lucas De Marchi wrote:
> On Thu, Jan 23, 2025 at 07:24:22PM +0530, Riana Tauro wrote:
>> Hi Lucas
>>
>> On 1/23/2025 9:49 AM, Lucas De Marchi wrote:
>>> Add the generic support for defining new attributes. This uses
>>> gt-c6-residency as first attribute to bootstrap it, but its
>>> implementation will be added by a follow up commit: until proper support
>>> is added, it will always be invisible in sysfs since the corresponding
>>> bit is not set in the supported_events bitmap.
>>>
>>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>>> ---
>>> drivers/gpu/drm/xe/xe_pmu.c | 60 ++++++++++++++++++++++++++++---
>>> drivers/gpu/drm/xe/xe_pmu_types.h | 4 +++
>>> 2 files changed, 60 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/xe/xe_pmu.c b/drivers/gpu/drm/xe/xe_pmu.c
>>> index 33598272db6aa..5e5a9fcf30ace 100644
>>> --- a/drivers/gpu/drm/xe/xe_pmu.c
>>> +++ b/drivers/gpu/drm/xe/xe_pmu.c
>>> @@ -46,6 +46,8 @@ static unsigned int config_to_gt_id(u64 config)
>>> return FIELD_GET(XE_PMU_EVENT_GT_MASK, config);
>>> }
>>> +#define XE_PMU_EVENT_GT_C6_RESIDENCY 0x01
>>> +
>>> static struct xe_gt *event_to_gt(struct perf_event *event)
>>> {
>>> struct xe_device *xe = container_of(event->pmu, typeof(*xe),
>>> pmu.base);
>>> @@ -60,7 +62,8 @@ static bool event_supported(struct xe_pmu *pmu,
>>> unsigned int gt,
>>> if (gt >= XE_MAX_GT_PER_TILE)
>>> return false;
>>> - return false;
>>> + return id < sizeof(pmu->supported_events) * BITS_PER_BYTE &&
>>> + pmu->supported_events & BIT_ULL(id);
>>> }
>>> static void xe_pmu_event_destroy(struct perf_event *event)
>>> @@ -210,16 +213,62 @@ static const struct attribute_group
>>> pmu_format_attr_group = {
>>> .attrs = pmu_format_attrs,
>>> };
>>> -static struct attribute *pmu_event_attrs[] = {
>>> - /* No events yet */
>>> +static ssize_t event_attr_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct perf_pmu_events_attr *pmu_attr =
>>> + container_of(attr, struct perf_pmu_events_attr, attr);
>>> +
>>> + return sprintf(buf, "event=%#04llx\n", pmu_attr->id);
>>> +}
>>> +
>>> +#define XE_EVENT_ATTR(name_, v_, id_, unit_) \
>>> + PMU_EVENT_ATTR(name_, pmu_event_ ## v_, id_, event_attr_show) \
>>> + PMU_EVENT_ATTR_STRING(name_.unit, pmu_event_unit_ ## v_,
>>> unit_) \
>>> + static struct attribute *pmu_attr_ ##v_[] = { \
>>> + &pmu_event_ ##v_.attr.attr, \
>>> + &pmu_event_unit_ ##v_.attr.attr, \
>>> + NULL \
>>> + }; \
>>> + static umode_t is_visible_##v_(struct kobject *kobj, \
>>> + struct attribute *attr, int idx) \
>>> + { \
>>> + struct perf_pmu_events_attr *pmu_attr; \
>>> + struct xe_pmu *pmu; \
>>> + \
>>> + pmu_attr = container_of(attr, typeof(*pmu_attr), attr.attr); \
>>> + pmu = container_of(dev_get_drvdata(kobj_to_dev(kobj)), \
>>> + typeof(*pmu), base); \
>>> + \
>>> + return event_supported(pmu, 0, id_) ? attr->mode : 0; \
>>> + } \
>>> + static const struct attribute_group pmu_group_ ##v_ = { \
>>> + .name = "events", \
>>> + .attrs = pmu_attr_ ## v_, \
>>> + .is_visible = is_visible_ ## v_, \
>>> + }
>>> +
>> There will be some events that do not have the unit. The previous rev
>> was simpler to handle such events
>>
>> Can the previous revision be retained?
>
> that would depend on merging the first patch in perf/core or bring that
> define here.
>
> I think we can live with the similar approach of other drivers above and
> in future try to add PMU_EVENT_ATTR_ID_STRING. However I'd like to have pmu
> merged in xe without depending on that.
Sorry, my bad. I missed that the core patch was removed in this series
And if we simply add the macro
> in xe, it means it will probably stay forever with nobody cleaning it up
> later.
>
> Also, what event are you talking about?
The upcoming per-engine-class-activity counters. They are similar to the
per-client and have no units.
There are 2 or 3 alternatives:
>
> 1) add a unit
>
> 2) add an indirection to the macro above to allow defining an event
> without unit. That's doable by having 3 macros: __XE_EVENT_ATTR,
> XE_EVENT_ATTR, and XE_EVENT_ATTR_WITH_UNIT. Then you'd have:
>
> XE_EVENT_ATTR_WITH_UNIT(foo, ...)
> XE_EVENT_ATTR(bar, ...)
>
>
> 3) Ungroup the macro so the group is separate, then we'd do:
>
> XE_EVENT_ATTR(foo)
> XE_EVENT_ATTR_UNIT(foo, "ms")
> XE_EVENT_GROUP(foo, &pmu_event_foo.attr.attr,
> &pmu_event_unit_foo.attr.attr)
>
> XE_EVENT_ATTR(bar)
> XE_EVENT_GROUP(bar, &pmu_event_bar.attr.attr)
>
Yeah will have to seperate it out.
Sorry for the confusion.
Thanks
Riana
> Lucas De Marchi
>
>>
>> Thanks
>> Riana
>>> +XE_EVENT_ATTR(gt-c6-residency, gt_c6_residency,
>>> XE_PMU_EVENT_GT_C6_RESIDENCY, "ms");
>>> +
>>> +static struct attribute *pmu_empty_event_attrs[] = {
>>> + /* Empty - all events are added as groups with .attr_update() */
>>> NULL,
>>> };
>>> static const struct attribute_group pmu_events_attr_group = {
>>> .name = "events",
>>> - .attrs = pmu_event_attrs,
>>> + .attrs = pmu_empty_event_attrs,
>>> };
>>> +static const struct attribute_group *pmu_events_attr_update[] = {
>>> + &pmu_group_gt_c6_residency,
>>> + NULL,
>>> +};
>>> +
>>> +static void set_supported_events(struct xe_pmu *pmu)
>>> +{
>>> +}
>>> +
>>> /**
>>> * xe_pmu_unregister() - Remove/cleanup PMU registration
>>> * @arg: Ptr to pmu
>>> @@ -270,6 +319,7 @@ int xe_pmu_register(struct xe_pmu *pmu)
>>> pmu->name = name;
>>> pmu->base.attr_groups = attr_groups;
>>> + pmu->base.attr_update = pmu_events_attr_update;
>>> pmu->base.scope = PERF_PMU_SCOPE_SYS_WIDE;
>>> pmu->base.module = THIS_MODULE;
>>> pmu->base.task_ctx_nr = perf_invalid_context;
>>> @@ -280,6 +330,8 @@ int xe_pmu_register(struct xe_pmu *pmu)
>>> pmu->base.stop = xe_pmu_event_stop;
>>> pmu->base.read = xe_pmu_event_read;
>>> + set_supported_events(pmu);
>>> +
>>> ret = perf_pmu_register(&pmu->base, pmu->name, -1);
>>> if (ret)
>>> goto err_name;
>>> diff --git a/drivers/gpu/drm/xe/xe_pmu_types.h b/drivers/gpu/drm/xe/
>>> xe_pmu_types.h
>>> index 0e8faae6bc1b3..f5ba4d56622cb 100644
>>> --- a/drivers/gpu/drm/xe/xe_pmu_types.h
>>> +++ b/drivers/gpu/drm/xe/xe_pmu_types.h
>>> @@ -30,6 +30,10 @@ struct xe_pmu {
>>> * @name: Name as registered with perf core.
>>> */
>>> const char *name;
>>> + /**
>>> + * @supported_events: Bitmap of supported events, indexed by
>>> event id
>>> + */
>>> + u64 supported_events;
>>> };
>>> #endif
>>
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