[Intel-gfx] [PATCH 1/4] drm/i915: Get active pending request for given context

[Kedar J. Karanje]

Hello Jani,


On Tuesday 25 September 2018 01:34 PM, Jani Nikula wrote:
> On Fri, 21 Sep 2018, kedar.j.karanje at intel.com wrote:
>> From: Praveen Diwakar <praveen.diwakar at intel.com>
>>
>> This patch gives us the active pending request count which is yet
>> to be submitted to the GPU
>>
>> Change-Id: I10c2828ad0f1a0b7af147835737134e07a2d5b6d
> Please remove these.
We will remove the Change-Ids in subsequent patches, thanks.
>
>> Signed-off-by: Praveen Diwakar <praveen.diwakar at intel.com>
>> Signed-off-by: Yogesh Marathe <yogesh.marathe at intel.com>
>> Signed-off-by: Aravindan Muthukumar <aravindan.muthukumar at intel.com>
>> Signed-off-by: Kedar J Karanje <kedar.j.karanje at intel.com>
>> Signed-off-by: Ankit Navik <ankit.p.navik at intel.com>
> What are you trying to convey with the five signoffs?
The guys who were working on this moved on to other teams, since we 
picked it up from where they left we have included the original authors 
and added new folks who would continue to work on it too, I am not sure 
of what is the protocol in such situations.
I referred to the guidelines at: 
https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html 
please do let me know if there are any changes in the same.

Thanks,
Kedar
>
> BR,
> Jani.
>
>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.c            | 1 +
>>   drivers/gpu/drm/i915/i915_drv.h            | 5 +++++
>>   drivers/gpu/drm/i915/i915_gem_context.c    | 1 +
>>   drivers/gpu/drm/i915/i915_gem_context.h    | 6 ++++++
>>   drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++++
>>   drivers/gpu/drm/i915/intel_lrc.c           | 6 ++++++
>>   6 files changed, 24 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index f8cfd16..d37c46e 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -903,6 +903,7 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
>>   	mutex_init(&dev_priv->av_mutex);
>>   	mutex_init(&dev_priv->wm.wm_mutex);
>>   	mutex_init(&dev_priv->pps_mutex);
>> +	mutex_init(&dev_priv->pred_mutex);
>>   
>>   	i915_memcpy_init_early(dev_priv);
>>   
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 4aca534..137ec33 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1609,6 +1609,11 @@ struct drm_i915_private {
>>   	 * controller on different i2c buses. */
>>   	struct mutex gmbus_mutex;
>>   
>> +	/** pred_mutex protects against councurrent usage of pending
>> +	 * request counter for multiple contexts
>> +	 */
>> +	struct mutex pred_mutex;
>> +
>>   	/**
>>   	 * Base address of the gmbus and gpio block.
>>   	 */
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
>> index b10770c..30932d9 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
>> @@ -387,6 +387,7 @@ i915_gem_create_context(struct drm_i915_private *dev_priv,
>>   	}
>>   
>>   	trace_i915_context_create(ctx);
>> +	ctx->req_cnt = 0;
>>   
>>   	return ctx;
>>   }
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
>> index b116e49..243ea22 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.h
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.h
>> @@ -194,6 +194,12 @@ struct i915_gem_context {
>>   	 * context close.
>>   	 */
>>   	struct list_head handles_list;
>> +
>> +	/** req_cnt: tracks the pending commands, based on which we decide to
>> +	 * go for low/medium/high load configuration of the GPU, this is
>> +	 * controlled via a mutex
>> +	 */
>> +	u64 req_cnt;
>>   };
>>   
>>   static inline bool i915_gem_context_is_closed(const struct i915_gem_context *ctx)
>> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> index 3f0c612..f799ff9 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> @@ -2178,6 +2178,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>>   		       struct drm_syncobj **fences)
>>   {
>>   	struct i915_execbuffer eb;
>> +	struct drm_i915_private *dev_priv = to_i915(dev);
>>   	struct dma_fence *in_fence = NULL;
>>   	struct sync_file *out_fence = NULL;
>>   	int out_fence_fd = -1;
>> @@ -2390,6 +2391,10 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>>   	 */
>>   	eb.request->batch = eb.batch;
>>   
>> +	mutex_lock(&dev_priv->pred_mutex);
>> +	eb.ctx->req_cnt++;
>> +	mutex_unlock(&dev_priv->pred_mutex);
>> +
>>   	trace_i915_request_queue(eb.request, eb.batch_flags);
>>   	err = eb_submit(&eb);
>>   err_request:
>> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
>> index 1744792..039fbdb 100644
>> --- a/drivers/gpu/drm/i915/intel_lrc.c
>> +++ b/drivers/gpu/drm/i915/intel_lrc.c
>> @@ -728,6 +728,12 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
>>   			trace_i915_request_in(rq, port_index(port, execlists));
>>   			last = rq;
>>   			submit = true;
>> +
>> +			mutex_lock(&rq->i915->pred_mutex);
>> +			if (rq->gem_context->req_cnt > 0) {
>> +				rq->gem_context->req_cnt--;
>> +			}
>> +			mutex_unlock(&rq->i915->pred_mutex);
>>   		}
>>   
>>   		rb_erase_cached(&p->node, &execlists->queue);