[PATCH v2 3/6] drm/xe: Add helper to accumulate exec queue runtime

[Tvrtko Ursulin]

On 26/04/2024 19:59, Umesh Nerlige Ramappa wrote:
> On Fri, Apr 26, 2024 at 11:49:32AM +0100, Tvrtko Ursulin wrote:
>>
>> On 24/04/2024 00:56, Lucas De Marchi wrote:
>>> From: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>>>
>>> Add a helper to accumulate per-client runtime of all its
>>> exec queues. Currently that is done in 2 places:
>>>
>>>     1. when the exec_queue is destroyed
>>>     2. when the sched job is completed
>>>
>>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>>> ---
>>>  drivers/gpu/drm/xe/xe_device_types.h |  9 +++++++
>>>  drivers/gpu/drm/xe/xe_exec_queue.c   | 37 ++++++++++++++++++++++++++++
>>>  drivers/gpu/drm/xe/xe_exec_queue.h   |  1 +
>>>  drivers/gpu/drm/xe/xe_sched_job.c    |  2 ++
>>>  4 files changed, 49 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/xe/xe_device_types.h 
>>> b/drivers/gpu/drm/xe/xe_device_types.h
>>> index 2e62450d86e1..33d3bf93a2f1 100644
>>> --- a/drivers/gpu/drm/xe/xe_device_types.h
>>> +++ b/drivers/gpu/drm/xe/xe_device_types.h
>>> @@ -547,6 +547,15 @@ struct xe_file {
>>>          struct mutex lock;
>>>      } exec_queue;
>>> +    /**
>>> +     * @runtime: hw engine class runtime in ticks for this drm client
>>> +     *
>>> +     * Only stats from xe_exec_queue->lrc[0] are accumulated. For 
>>> multi-lrc
>>> +     * case, since all jobs run in parallel on the engines, only the 
>>> stats
>>> +     * from lrc[0] are sufficient.
>>
>> Out of curiousity doesn't this mean multi-lrc jobs will be incorrectly 
>> accounted for? (When capacity is considered.)
> 
> TBH, I am not sure what the user would like to see here for multi-lrc. 
> If reporting the capacity, then we may need to use width as a 
> multiplication factor for multi-lrc. How was this done in i915?

IMO user has to see the real utilisation - so if there are two VCS and 
both are busy, 100% should be reported and not 50%. Latter would be 
misleading, either with or without cross-checking with physical utilisation.

In i915 with execlists this works correctly and with GuC you would 
probably know the answer better than me.

Regards,

Tvrtko

> 
> Regards,
> Umesh
> 
> 
>>
>> Regards,
>>
>> Tvrtko
>>
>>> +     */
>>> +    u64 runtime[XE_ENGINE_CLASS_MAX];
>>> +
>>>      /** @client: drm client */
>>>      struct xe_drm_client *client;
>>>  };
>>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c 
>>> b/drivers/gpu/drm/xe/xe_exec_queue.c
>>> index 395de93579fa..b7b6256cb96a 100644
>>> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
>>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>>> @@ -214,6 +214,8 @@ void xe_exec_queue_fini(struct xe_exec_queue *q)
>>>  {
>>>      int i;
>>> +    xe_exec_queue_update_runtime(q);
>>> +
>>>      for (i = 0; i < q->width; ++i)
>>>          xe_lrc_finish(q->lrc + i);
>>>      if (!(q->flags & EXEC_QUEUE_FLAG_PERMANENT) && (q->flags & 
>>> EXEC_QUEUE_FLAG_VM || !q->vm))
>>> @@ -769,6 +771,41 @@ bool xe_exec_queue_is_idle(struct xe_exec_queue *q)
>>>          q->lrc[0].fence_ctx.next_seqno - 1;
>>>  }
>>> +/**
>>> + * xe_exec_queue_update_runtime() - Update runtime for this exec 
>>> queue from hw
>>> + * @q: The exec queue
>>> + *
>>> + * Update the timestamp saved by HW for this exec queue and save 
>>> runtime
>>> + * calculated by using the delta from last update. On multi-lrc 
>>> case, only the
>>> + * first is considered.
>>> + */
>>> +void xe_exec_queue_update_runtime(struct xe_exec_queue *q)
>>> +{
>>> +    struct xe_file *xef;
>>> +    struct xe_lrc *lrc;
>>> +    u32 old_ts, new_ts;
>>> +
>>> +    /*
>>> +     * Jobs that are run during driver load may use an exec_queue, 
>>> but are
>>> +     * not associated with a user xe file, so avoid accumulating 
>>> busyness
>>> +     * for kernel specific work.
>>> +     */
>>> +    if (!q->vm || !q->vm->xef)
>>> +        return;
>>> +
>>> +    xef = q->vm->xef;
>>> +    lrc = &q->lrc[0];
>>> +
>>> +    new_ts = xe_lrc_update_timestamp(lrc, &old_ts);
>>> +
>>> +    /*
>>> +     * Special case the very first timestamp: we don't want the
>>> +     * initial delta to be a huge value
>>> +     */
>>> +    if (old_ts)
>>> +        xef->runtime[q->class] += new_ts - old_ts;
>>> +}
>>> +
>>>  void xe_exec_queue_kill(struct xe_exec_queue *q)
>>>  {
>>>      struct xe_exec_queue *eq = q, *next;
>>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h 
>>> b/drivers/gpu/drm/xe/xe_exec_queue.h
>>> index 02ce8d204622..45b72daa2db3 100644
>>> --- a/drivers/gpu/drm/xe/xe_exec_queue.h
>>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.h
>>> @@ -66,5 +66,6 @@ struct dma_fence 
>>> *xe_exec_queue_last_fence_get(struct xe_exec_queue *e,
>>>                             struct xe_vm *vm);
>>>  void xe_exec_queue_last_fence_set(struct xe_exec_queue *e, struct 
>>> xe_vm *vm,
>>>                    struct dma_fence *fence);
>>> +void xe_exec_queue_update_runtime(struct xe_exec_queue *q);
>>>  #endif
>>> diff --git a/drivers/gpu/drm/xe/xe_sched_job.c 
>>> b/drivers/gpu/drm/xe/xe_sched_job.c
>>> index cd8a2fba5438..6a081a4fa190 100644
>>> --- a/drivers/gpu/drm/xe/xe_sched_job.c
>>> +++ b/drivers/gpu/drm/xe/xe_sched_job.c
>>> @@ -242,6 +242,8 @@ bool xe_sched_job_completed(struct xe_sched_job 
>>> *job)
>>>  {
>>>      struct xe_lrc *lrc = job->q->lrc;
>>> +    xe_exec_queue_update_runtime(job->q);
>>> +
>>>      /*
>>>       * Can safely check just LRC[0] seqno as that is last seqno 
>>> written when
>>>       * parallel handshake is done.