[Intel-gfx] [PATCH 6/9] drm/i915/pmu: Export counters from all tiles

Tvrtko Ursulin tvrtko.ursulin at linux.intel.com
Thu Mar 30 13:01:42 UTC 2023


On 30/03/2023 01:41, Umesh Nerlige Ramappa wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Start exporting frequency and RC6 counters from all tiles.
> 
> Existing counters keep their names and config values and new one use the
> namespace added in the previous patch, with the "-gtN" added to their
> names.

The part about keeping the names is not in the code any more. So something will have to give, either the commit text or the code.

Even without that detail, I suspect someone might want to add them Co-developed-by since I *think* someone did some changes.
  
> Interrupts counter is an odd one off. Because it is the global device
> counters (not only GT) we choose not to add per tile versions for now.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_pmu.c | 96 ++++++++++++++++++++++++++-------
>   1 file changed, 77 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
> index 5d1de98d86b4..2a5deabff088 100644
> --- a/drivers/gpu/drm/i915/i915_pmu.c
> +++ b/drivers/gpu/drm/i915/i915_pmu.c
> @@ -548,8 +548,9 @@ config_status(struct drm_i915_private *i915, u64 config)
>   	struct intel_gt *gt = to_gt(i915);
>   
>   	unsigned int gt_id = config_gt_id(config);
> +	unsigned int max_gt_id = HAS_EXTRA_GT_LIST(i915) ? 1 : 0;
>   
> -	if (gt_id)
> +	if (gt_id > max_gt_id)
>   		return -ENOENT;
>   
>   	switch (config_counter(config)) {
> @@ -563,6 +564,8 @@ config_status(struct drm_i915_private *i915, u64 config)
>   			return -ENODEV;
>   		break;
>   	case I915_PMU_INTERRUPTS:
> +		if (gt_id)
> +			return -ENOENT;
>   		break;
>   	case I915_PMU_RC6_RESIDENCY:
>   		if (!gt->rc6.supported)
> @@ -932,9 +935,9 @@ static const struct attribute_group i915_pmu_cpumask_attr_group = {
>   	.attrs = i915_cpumask_attrs,
>   };
>   
> -#define __event(__config, __name, __unit) \
> +#define __event(__counter, __name, __unit) \
>   { \
> -	.config = (__config), \
> +	.counter = (__counter), \
>   	.name = (__name), \
>   	.unit = (__unit), \
>   }
> @@ -975,15 +978,21 @@ create_event_attributes(struct i915_pmu *pmu)
>   {
>   	struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
>   	static const struct {
> -		u64 config;
> +		unsigned int counter;
>   		const char *name;
>   		const char *unit;
>   	} events[] = {
> -		__event(I915_PMU_ACTUAL_FREQUENCY, "actual-frequency", "M"),
> -		__event(I915_PMU_REQUESTED_FREQUENCY, "requested-frequency", "M"),
> -		__event(I915_PMU_INTERRUPTS, "interrupts", NULL),
> -		__event(I915_PMU_RC6_RESIDENCY, "rc6-residency", "ns"),
> -		__event(I915_PMU_SOFTWARE_GT_AWAKE_TIME, "software-gt-awake-time", "ns"),
> +		__event(0, "actual-frequency", "M"),
> +		__event(1, "requested-frequency", "M"),
> +		__event(3, "rc6-residency", "ns"),
> +		__event(4, "software-gt-awake-time", "ns"),
> +	};
> +	static const struct {
> +		unsigned int counter;
> +		const char *name;
> +		const char *unit;
> +	} global_events[] = {
> +		__event(2, "interrupts", NULL),
>   	};
>   	static const struct {
>   		enum drm_i915_pmu_engine_sample sample;
> @@ -998,14 +1007,29 @@ create_event_attributes(struct i915_pmu *pmu)
>   	struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
>   	struct attribute **attr = NULL, **attr_iter;
>   	struct intel_engine_cs *engine;
> -	unsigned int i;
> +	struct intel_gt *gt;
> +	unsigned int i, j;
>   
>   	/* Count how many counters we will be exposing. */
> -	for (i = 0; i < ARRAY_SIZE(events); i++) {
> -		if (!config_status(i915, events[i].config))
> +	/* per gt counters */

Two comments one by another, two styles - the inconsistency hurts.

Not sure why global events needed to be split out into a separate array? Like this below two loops are needed for each stage instead of one. AFAIR one array and one loop would just work because config_status wold report global ones as unsupported for gt > 0.

[Comes back later. It looked like this in my code:

         static const struct {
-               u64 config;
+               unsigned int counter;
                 const char *name;
                 const char *unit;
+               bool global;
         } events[] = {
-               __event(I915_PMU_ACTUAL_FREQUENCY, "actual-frequency", "M"),
-               __event(I915_PMU_REQUESTED_FREQUENCY, "requested-frequency", "M"),
-               __event(I915_PMU_INTERRUPTS, "interrupts", NULL),
-               __event(I915_PMU_RC6_RESIDENCY, "rc6-residency", "ns"),
+               /*
+                * #define __I915_PMU_ACTUAL_FREQUENCY(gt)    ___I915_PMU_OTHER(gt, 0)
+                * #define __I915_PMU_REQUESTED_FREQUENCY(gt) ___I915_PMU_OTHER(gt, 1)
+                * #define __I915_PMU_INTERRUPTS(gt)          ___I915_PMU_OTHER(gt, 2)
+                * #define __I915_PMU_RC6_RESIDENCY(gt)       ___I915_PMU_OTHER(gt, 3)
+                */
+               __event(0, "actual-frequency", "M"),
+               __event(1, "requested-frequency", "M"),
+               __global_event(2, "interrupts", NULL),
+               __event(3, "rc6-residency", "ns"),

...

         /* Count how many counters we will be exposing. */
-       for (i = 0; i < ARRAY_SIZE(events); i++) {
-               if (!config_status(i915, events[i].config))
-                       count++;
+       for_each_gt(i915, j, gt) {
+               for (i = 0; i < ARRAY_SIZE(events); i++) {
+                       u64 config = ___I915_PMU_OTHER(j, events[i].counter);
+
+                       if (!config_status(i915, config))
+                               count++;
+               }

So AFAICT it just worked.

]

> +	for_each_gt(gt, i915, j) {
> +		for (i = 0; i < ARRAY_SIZE(events); i++) {
> +			u64 config = ___I915_PMU_OTHER(j, events[i].counter);
> +
> +			if (!config_status(i915, config))
> +				count++;
> +		}
> +	}
> +
> +	/* global (per GPU) counters */
> +	for (i = 0; i < ARRAY_SIZE(global_events); i++) {
> +		u64 config = ___I915_PMU_OTHER(0, global_events[i].counter);
> +
> +		if (!config_status(i915, config))
>   			count++;
>   	}
>   
> +	/* per engine counters */
>   	for_each_uabi_engine(engine, i915) {
>   		for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
>   			if (!engine_event_status(engine,
> @@ -1033,26 +1057,60 @@ create_event_attributes(struct i915_pmu *pmu)
>   	attr_iter = attr;
>   
>   	/* Initialize supported non-engine counters. */
> -	for (i = 0; i < ARRAY_SIZE(events); i++) {
> +	/* per gt counters */
> +	for_each_gt(gt, i915, j) {
> +		for (i = 0; i < ARRAY_SIZE(events); i++) {
> +			u64 config = ___I915_PMU_OTHER(j, events[i].counter);
> +			char *str;
> +
> +			if (config_status(i915, config))
> +				continue;
> +
> +			str = kasprintf(GFP_KERNEL, "%s-gt%u",
> +					events[i].name, j);

So with this patch all old platforms change the event names. This is not how I wrote it, and more importantly, it breaks userspace. Why would we do it?

For reference I dug out my code from 2020 and it looked like this:

+                       if (events[i].global || !i915->remote_tiles)
+                               str = kstrdup(events[i].name, GFP_KERNEL);
+                       else
+                               str = kasprintf(GFP_KERNEL, "%s-gt%u",
+                                               events[i].name, j);

So on single tile platforms names remain the same.

Regards,

Tvrtko

> +			if (!str)
> +				goto err;
> +
> +			*attr_iter++ = &i915_iter->attr.attr;
> +			i915_iter = add_i915_attr(i915_iter, str, config);
> +
> +			if (events[i].unit) {
> +				str = kasprintf(GFP_KERNEL, "%s-gt%u.unit",
> +						events[i].name, j);
> +				if (!str)
> +					goto err;
> +
> +				*attr_iter++ = &pmu_iter->attr.attr;
> +				pmu_iter = add_pmu_attr(pmu_iter, str,
> +							events[i].unit);
> +			}
> +		}
> +	}
> +
> +	/* global (per GPU) counters */
> +	for (i = 0; i < ARRAY_SIZE(global_events); i++) {
> +		u64 config = ___I915_PMU_OTHER(0, global_events[i].counter);
>   		char *str;
>   
> -		if (config_status(i915, events[i].config))
> +		if (config_status(i915, config))
>   			continue;
>   
> -		str = kstrdup(events[i].name, GFP_KERNEL);
> +		str = kstrdup(global_events[i].name, GFP_KERNEL);
>   		if (!str)
>   			goto err;
>   
>   		*attr_iter++ = &i915_iter->attr.attr;
> -		i915_iter = add_i915_attr(i915_iter, str, events[i].config);
> +		i915_iter = add_i915_attr(i915_iter, str, config);
>   
> -		if (events[i].unit) {
> -			str = kasprintf(GFP_KERNEL, "%s.unit", events[i].name);
> +		if (global_events[i].unit) {
> +			str = kasprintf(GFP_KERNEL, "%s.unit",
> +					global_events[i].name);
>   			if (!str)
>   				goto err;
>   
>   			*attr_iter++ = &pmu_iter->attr.attr;
> -			pmu_iter = add_pmu_attr(pmu_iter, str, events[i].unit);
> +			pmu_iter = add_pmu_attr(pmu_iter, str,
> +						global_events[i].unit);
>   		}
>   	}
>   


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