[Intel-gfx] [PATCH 3/3] drm/i915/mtl: Add counters for engine busyness ticks

John Harrison john.c.harrison at intel.com
Thu Oct 19 19:56:52 UTC 2023


On 10/19/2023 09:21, Dong, Zhanjun wrote:
> See comments inline below.
>
> Zhanjun
>
> On 2023-09-22 6:25 p.m., John.C.Harrison at Intel.com wrote:
>> From: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>>
>> In new version of GuC engine busyness, GuC provides engine busyness
>> ticks as a 64 bit counter. Add a new counter to relay this value to the
>> user as is.
>>
>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_engine.h        |  1 +
>>   drivers/gpu/drm/i915/gt/intel_engine_cs.c     | 16 +++++
>>   drivers/gpu/drm/i915/gt/intel_engine_types.h  | 12 ++++
>>   drivers/gpu/drm/i915/gt/intel_engine_user.c   |  1 +
>>   .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 67 ++++++++++++++-----
>>   drivers/gpu/drm/i915/i915_pmu.c               | 25 ++++++-
>>   drivers/gpu/drm/i915/i915_pmu.h               |  2 +-
>>   include/uapi/drm/i915_drm.h                   | 13 +++-
>>   8 files changed, 116 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h 
>> b/drivers/gpu/drm/i915/gt/intel_engine.h
>> index b58c30ac8ef02..57af7ec8ecd82 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_engine.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_engine.h
>> @@ -249,6 +249,7 @@ void intel_engine_dump_active_requests(struct 
>> list_head *requests,
>>     ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine,
>>                      ktime_t *now);
>> +u64 intel_engine_get_busy_ticks(struct intel_engine_cs *engine);
>>     void intel_engine_get_hung_entity(struct intel_engine_cs *engine,
>>                     struct intel_context **ce, struct i915_request 
>> **rq);
>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c 
>> b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>> index 84a75c95f3f7d..1c9ffb1ae9889 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>> @@ -2426,6 +2426,22 @@ ktime_t intel_engine_get_busy_time(struct 
>> intel_engine_cs *engine, ktime_t *now)
>>       return engine->busyness(engine, now);
>>   }
>>   +/**
>> + * intel_engine_get_busy_ticks() - Return current accumulated engine 
>> busyness
>> + * ticks
>> + * @engine: engine to report on
>> + *
>> + * Returns accumulated ticks @engine was busy since engine stats 
>> were enabled.
>> + */
>> +u64 intel_engine_get_busy_ticks(struct intel_engine_cs *engine)
>> +{
>> +    if (!engine->busyness_ticks ||
>> +        !(engine->flags & I915_ENGINE_SUPPORTS_TICKS_STATS))
>> +        return 0;
>> +
>> +    return engine->busyness_ticks(engine);
>> +}
>> +
>>   struct intel_context *
>>   intel_engine_create_virtual(struct intel_engine_cs **siblings,
>>                   unsigned int count, unsigned long flags)
>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h 
>> b/drivers/gpu/drm/i915/gt/intel_engine_types.h
>> index 40fd8f984d64b..a88d40c74d604 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
>> @@ -548,6 +548,11 @@ struct intel_engine_cs {
>>       ktime_t        (*busyness)(struct intel_engine_cs *engine,
>>                       ktime_t *now);
>>   +    /*
>> +     * Get engine busyness ticks
>> +     */
>> +    u64        (*busyness_ticks)(struct intel_engine_cs *engine);
>> +
>>       struct intel_engine_execlists execlists;
>>         /*
>> @@ -574,6 +579,7 @@ struct intel_engine_cs {
>>   #define I915_ENGINE_HAS_EU_PRIORITY    BIT(10)
>>   #define I915_ENGINE_FIRST_RENDER_COMPUTE BIT(11)
>>   #define I915_ENGINE_USES_WA_HOLD_CCS_SWITCHOUT BIT(12)
>> +#define I915_ENGINE_SUPPORTS_TICKS_STATS   BIT(13)
>>       unsigned int flags;
>>         /*
>> @@ -649,6 +655,12 @@ intel_engine_supports_stats(const struct 
>> intel_engine_cs *engine)
>>       return engine->flags & I915_ENGINE_SUPPORTS_STATS;
>>   }
>>   +static inline bool
>> +intel_engine_supports_tick_stats(const struct intel_engine_cs *engine)
>> +{
>> +    return engine->flags & I915_ENGINE_SUPPORTS_TICKS_STATS;
>> +}
>> +
>>   static inline bool
>>   intel_engine_has_preemption(const struct intel_engine_cs *engine)
>>   {
>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c 
>> b/drivers/gpu/drm/i915/gt/intel_engine_user.c
>> index dcedff41a825f..69eb610b5ab0a 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
>> @@ -100,6 +100,7 @@ static void set_scheduler_caps(struct 
>> drm_i915_private *i915)
>>           MAP(HAS_PREEMPTION, PREEMPTION),
>>           MAP(HAS_SEMAPHORES, SEMAPHORES),
>>           MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
>> +        MAP(SUPPORTS_TICKS_STATS, ENGINE_BUSY_TICKS_STATS),
>>   #undef MAP
>>       };
>>       struct intel_engine_cs *engine;
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c 
>> b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> index 0c1fee5360777..71749fb9ad35b 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> @@ -1289,12 +1289,7 @@ static void 
>> busy_v1_guc_update_pm_timestamp(struct intel_guc *guc, ktime_t *now)
>>       guc->busy.v1.gt_stamp = ((u64)gt_stamp_hi << 32) | gt_stamp_lo;
>>   }
>>   -/*
>> - * Unlike the execlist mode of submission total and active times are 
>> in terms of
>> - * gt clocks. The *now parameter is retained to return the cpu time 
>> at which the
>> - * busyness was sampled.
>> - */
>> -static ktime_t busy_v1_guc_engine_busyness(struct intel_engine_cs 
>> *engine, ktime_t *now)
>> +static u64 __busy_v1_guc_engine_busyness_ticks(struct 
>> intel_engine_cs *engine, ktime_t *now_out)
>>   {
>>       struct intel_engine_guc_stats_v1 stats_saved, *stats = 
>> &engine->stats.guc_v1;
>>       struct i915_gpu_error *gpu_error = &engine->i915->gpu_error;
>> @@ -1304,6 +1299,7 @@ static ktime_t 
>> busy_v1_guc_engine_busyness(struct intel_engine_cs *engine, ktime
>>       unsigned long flags;
>>       u32 reset_count;
>>       bool in_reset;
>> +    ktime_t now;
>>         spin_lock_irqsave(&guc->busy.v1.lock, flags);
>>   @@ -1318,7 +1314,7 @@ static ktime_t 
>> busy_v1_guc_engine_busyness(struct intel_engine_cs *engine, ktime
>>       reset_count = i915_reset_count(gpu_error);
>>       in_reset = test_bit(I915_RESET_BACKOFF, &gt->reset.flags);
>>   -    *now = ktime_get();
>> +    now = ktime_get();
>>         /*
>>        * The active busyness depends on start_gt_clk and gt_stamp.
>> @@ -1334,7 +1330,7 @@ static ktime_t 
>> busy_v1_guc_engine_busyness(struct intel_engine_cs *engine, ktime
>>            * start_gt_clk' calculation below for active engines.
>>            */
>>           busy_v1_guc_update_engine_gt_clks(engine);
>> -        busy_v1_guc_update_pm_timestamp(guc, now);
>> +        busy_v1_guc_update_pm_timestamp(guc, &now);
>>           intel_gt_pm_put_async(gt);
>>           if (i915_reset_count(gpu_error) != reset_count) {
>>               *stats = stats_saved;
>> @@ -1342,16 +1338,37 @@ static ktime_t 
>> busy_v1_guc_engine_busyness(struct intel_engine_cs *engine, ktime
>>           }
>>       }
>>   -    total = intel_gt_clock_interval_to_ns(gt, stats->total_gt_clks);
>> +    total = stats->total_gt_clks;
>>       if (stats->running) {
>>           u64 clk = guc->busy.v1.gt_stamp - stats->start_gt_clk;
>>   -        total += intel_gt_clock_interval_to_ns(gt, clk);
>> +        total += clk;
>>       }
>>         spin_unlock_irqrestore(&guc->busy.v1.lock, flags);
>>   -    return ns_to_ktime(total);
>> +    if (now_out)
>> +        *now_out = now;
>> +
>> +    return total;
>> +}
>> +
>> +/*
>> + * Unlike the execlist mode of submission total and active times are 
>> in terms of
>> + * gt clocks. The *now parameter is retained to return the cpu time 
>> at which the
>> + * busyness was sampled.
>> + */
>> +static ktime_t busy_v1_guc_engine_busyness(struct intel_engine_cs 
>> *engine, ktime_t *now)
>> +{
>> +    u64 ticks = __busy_v1_guc_engine_busyness_ticks(engine, now);
>> +    u64 ns = intel_gt_clock_interval_to_ns(engine->gt, ticks);
>> +
>> +    return ns_to_ktime(ns);
>> +}
>> +
>> +static u64 busy_v1_guc_engine_busyness_ticks(struct intel_engine_cs 
>> *engine)
>> +{
>> +    return __busy_v1_guc_engine_busyness_ticks(engine, NULL);
>>   }
>>     static void busy_v1_guc_enable_worker(struct intel_guc *guc)
>> @@ -1607,6 +1624,16 @@ static ktime_t 
>> busy_v2_guc_engine_busyness(struct intel_engine_cs *engine, ktime
>>       return ns_to_ktime(total);
>>   }
>>   +static u64 busy_v2_guc_engine_busyness_ticks(struct 
>> intel_engine_cs *engine)
>> +{
>> +    struct intel_guc *guc = &engine->gt->uc.guc;
>> +    u64 ticks_engine;
>> +
>> +    __busy_v2_get_engine_usage_record(guc, engine, &ticks_engine, 
>> NULL, NULL);
>> +
>> +    return ticks_engine;
>> +}
>> +
>>   static u64 busy_v1_intel_guc_total_active_ticks(struct intel_guc *guc)
>>   {
>>       return guc->busy.v1.gt_stamp;
>> @@ -4480,12 +4507,20 @@ static void guc_default_vfuncs(struct 
>> intel_engine_cs *engine)
>>           engine->emit_flush = gen12_emit_flush_xcs;
>>       }
>>       engine->set_default_submission = guc_set_default_submission;
>> -    if (GUC_SUBMIT_VER(&engine->gt->uc.guc) < MAKE_GUC_VER(1, 3, 1))
>> -        engine->busyness = busy_v1_guc_engine_busyness;
>> -    else
>> -        engine->busyness = busy_v2_guc_engine_busyness;
>> +    if (GUC_SUBMIT_VER(&engine->gt->uc.guc) < MAKE_GUC_VER(1, 3, 1)) {
>> +        if (GRAPHICS_VER_FULL(engine->i915) < IP_VER(12, 70))
>> +            engine->busyness = busy_v1_guc_engine_busyness;
>> +        engine->busyness_ticks = busy_v1_guc_engine_busyness_ticks;
>> +    } else {
>> +        if (GRAPHICS_VER_FULL(engine->i915) < IP_VER(12, 70))
>> +            engine->busyness = busy_v2_guc_engine_busyness;
>
> Do we leave engine->busyness not initialized when >= IP_VER(12, 70)?
These vfuncs are all zero initialised and checked for null before being 
called. And the intention was that MTL would not support the old API as 
it not a good fit for current hardware. However, that plan was rejected 
and the whole v2 implementation is currently shelved for upstream due to 
power implications that need to be resolved.

John.


>
>> +        engine->busyness_ticks = busy_v2_guc_engine_busyness_ticks;
>> +    }
>> +
>> +    if (engine->busyness)
>> +        engine->flags |= I915_ENGINE_SUPPORTS_STATS;
>>   -    engine->flags |= I915_ENGINE_SUPPORTS_STATS;
>> +    engine->flags |= I915_ENGINE_SUPPORTS_TICKS_STATS;
>>       engine->flags |= I915_ENGINE_HAS_PREEMPTION;
>>       engine->flags |= I915_ENGINE_HAS_TIMESLICES;
>>   diff --git a/drivers/gpu/drm/i915/i915_pmu.c 
>> b/drivers/gpu/drm/i915/i915_pmu.c
>> index 4f52636eb4a80..1b859556644f6 100644
>> --- a/drivers/gpu/drm/i915/i915_pmu.c
>> +++ b/drivers/gpu/drm/i915/i915_pmu.c
>> @@ -26,7 +26,8 @@
>>   #define ENGINE_SAMPLE_MASK \
>>       (BIT(I915_SAMPLE_BUSY) | \
>>        BIT(I915_SAMPLE_WAIT) | \
>> -     BIT(I915_SAMPLE_SEMA))
>> +     BIT(I915_SAMPLE_SEMA) | \
>> +     BIT(I915_SAMPLE_BUSY_TICKS))
>>     static cpumask_t i915_pmu_cpumask;
>>   static unsigned int i915_pmu_target_cpu = -1;
>> @@ -161,8 +162,11 @@ static bool pmu_needs_timer(struct i915_pmu *pmu)
>>        * Also there is software busyness tracking available we do not
>>        * need the timer for I915_SAMPLE_BUSY counter.
>>        */
>> -    if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
>> +    if ((i915->caps.scheduler & 
>> I915_SCHEDULER_CAP_ENGINE_BUSY_STATS) ||
>> +        (i915->caps.scheduler & 
>> I915_SCHEDULER_CAP_ENGINE_BUSY_TICKS_STATS)) {
>>           enable &= ~BIT(I915_SAMPLE_BUSY);
>> +        enable &= ~BIT(I915_SAMPLE_BUSY_TICKS);
>> +    }
>>         /*
>>        * If some bits remain it means we need the sampling timer 
>> running.
>> @@ -362,7 +366,8 @@ static void engine_sample(struct intel_engine_cs 
>> *engine, unsigned int period_ns
>>           add_sample(&pmu->sample[I915_SAMPLE_SEMA], period_ns);
>>         /* No need to sample when busy stats are supported. */
>> -    if (intel_engine_supports_stats(engine))
>> +    if (intel_engine_supports_stats(engine) ||
>> +        intel_engine_supports_tick_stats(engine))
>>           return;
>>         /*
>> @@ -519,6 +524,13 @@ engine_event_status(struct intel_engine_cs *engine,
>>   {
>>       switch (sample) {
>>       case I915_SAMPLE_BUSY:
>> +        if (!intel_engine_supports_stats(engine))
>> +            return -ENODEV;
>> +        break;
>> +    case I915_SAMPLE_BUSY_TICKS:
>> +        if (!intel_engine_supports_tick_stats(engine))
>> +            return -ENODEV;
>> +        break;
>>       case I915_SAMPLE_WAIT:
>>           break;
>>       case I915_SAMPLE_SEMA:
>> @@ -651,6 +663,9 @@ static u64 __i915_pmu_event_read(struct 
>> perf_event *event)
>>                 val = ktime_to_ns(intel_engine_get_busy_time(engine,
>>                                        &unused));
>> +        } else if (sample == I915_SAMPLE_BUSY_TICKS &&
>> +               intel_engine_supports_tick_stats(engine)) {
>> +            val = intel_engine_get_busy_ticks(engine);
>>           } else {
>>               val = engine->pmu.sample[sample].cur;
>>           }
>> @@ -1000,6 +1015,7 @@ create_event_attributes(struct i915_pmu *pmu)
>>           __engine_event(I915_SAMPLE_BUSY, "busy"),
>>           __engine_event(I915_SAMPLE_SEMA, "sema"),
>>           __engine_event(I915_SAMPLE_WAIT, "wait"),
>> +        __engine_event(I915_SAMPLE_BUSY_TICKS, "busy-ticks"),
>>       };
>>       unsigned int count = 0;
>>       struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
>> @@ -1103,6 +1119,9 @@ create_event_attributes(struct i915_pmu *pmu)
>>                                   engine->uabi_instance,
>>                                   engine_events[i].sample));
>>   +            if (engine_events[i].sample == I915_SAMPLE_BUSY_TICKS)
>> +                continue;
>> +
>>               str = kasprintf(GFP_KERNEL, "%s-%s.unit",
>>                       engine->name, engine_events[i].name);
>>               if (!str)
>> diff --git a/drivers/gpu/drm/i915/i915_pmu.h 
>> b/drivers/gpu/drm/i915/i915_pmu.h
>> index 41af038c37388..72a9c71944f8d 100644
>> --- a/drivers/gpu/drm/i915/i915_pmu.h
>> +++ b/drivers/gpu/drm/i915/i915_pmu.h
>> @@ -49,7 +49,7 @@ enum {
>>       (I915_ENGINE_SAMPLE_COUNT + \
>>        I915_PMU_MAX_GT * __I915_PMU_TRACKED_EVENT_COUNT)
>>   -#define I915_ENGINE_SAMPLE_COUNT (I915_SAMPLE_SEMA + 1)
>> +#define I915_ENGINE_SAMPLE_COUNT (I915_SAMPLE_BUSY_TICKS + 1)
>>     struct i915_pmu_sample {
>>       u64 cur;
>> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>> index e26dd27ff4a5f..8ae98c1bda0ea 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -257,7 +257,8 @@ struct i915_engine_class_instance {
>>   enum drm_i915_pmu_engine_sample {
>>       I915_SAMPLE_BUSY = 0,
>>       I915_SAMPLE_WAIT = 1,
>> -    I915_SAMPLE_SEMA = 2
>> +    I915_SAMPLE_SEMA = 2,
>> +    I915_SAMPLE_BUSY_TICKS = 3,
>>   };
>>     #define I915_PMU_SAMPLE_BITS (4)
>> @@ -274,6 +275,9 @@ enum drm_i915_pmu_engine_sample {
>>   #define I915_PMU_ENGINE_BUSY(class, instance) \
>>       __I915_PMU_ENGINE(class, instance, I915_SAMPLE_BUSY)
>>   +#define I915_PMU_ENGINE_BUSY_TICKS(class, instance) \
>> +    __I915_PMU_ENGINE(class, instance, I915_SAMPLE_BUSY_TICKS)
>> +
>>   #define I915_PMU_ENGINE_WAIT(class, instance) \
>>       __I915_PMU_ENGINE(class, instance, I915_SAMPLE_WAIT)
>>   @@ -651,7 +655,14 @@ typedef struct drm_i915_irq_wait {
>>   #define   I915_SCHEDULER_CAP_PRIORITY    (1ul << 1)
>>   #define   I915_SCHEDULER_CAP_PREEMPTION    (1ul << 2)
>>   #define   I915_SCHEDULER_CAP_SEMAPHORES    (1ul << 3)
>> +/*
>> + * BUSY_STATS is deprecated on platforms with GuC based submission 
>> and will nt
>> + * be available at all on newer platforms. It has accuracy issues 
>> due to the
>> + * conversions from tick counts to wall time.
>> + * BUSY_TICKS_STATS should be used instead.
>> + */
>>   #define   I915_SCHEDULER_CAP_ENGINE_BUSY_STATS    (1ul << 4)
>> +#define   I915_SCHEDULER_CAP_ENGINE_BUSY_TICKS_STATS    (1ul << 5)
>>   /*
>>    * Indicates the 2k user priority levels are statically mapped into 
>> 3 buckets as
>>    * follows:



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