Re: [PATCH v6 3/7] drm/xe: Add xe_exec_queue_last_fence_test_dep

[Matthew Brost <matthew.brost@intel.com>]

On Thu, Jun 27, 2024 at 05:36:42PM +0100, Matthew Auld wrote:
> On 26/06/2024 22:15, Matthew Brost wrote:
> > Helpful to determine if a bind can immediately use CPU or needs to be
> > deferred a drm scheduler job.
> > 
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > ---
> >   drivers/gpu/drm/xe/xe_exec_queue.c | 23 +++++++++++++++++++++++
> >   drivers/gpu/drm/xe/xe_exec_queue.h |  2 ++
> >   2 files changed, 25 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
> > index 0ba37835849b..65b4d1da6c93 100644
> > --- a/drivers/gpu/drm/xe/xe_exec_queue.c
> > +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
> > @@ -906,3 +906,26 @@ void xe_exec_queue_last_fence_set(struct xe_exec_queue *q, struct xe_vm *vm,
> >   	xe_exec_queue_last_fence_put(q, vm);
> >   	q->last_fence = dma_fence_get(fence);
> >   }
> > +
> > +/**
> > + * xe_exec_queue_last_fence_test_dep - Test last fence dependency of queue
> > + * @q: The exec queue
> > + * @vm: The VM the engine does a bind or exec for
> > + *
> > + * Returns:
> > + * 0 on success on dependency, -ETIME on dependency
> 
> Could maybe improve the wording here?
> 
> "-ETIME if there exists an unsignalled last fence dependency, zero
> otherwise."
> 

Will fix upon merge or in next rev if one is required.

Matt

> ?
> 
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
> 
> > + */
> > +int xe_exec_queue_last_fence_test_dep(struct xe_exec_queue *q, struct xe_vm *vm)
> > +{
> > +	struct dma_fence *fence;
> > +	int err = 0;
> > +
> > +	fence = xe_exec_queue_last_fence_get(q, vm);
> > +	if (fence) {
> > +		err = test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) ?
> > +			0 : -ETIME;
> > +		dma_fence_put(fence);
> > +	}
> > +
> > +	return err;
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h b/drivers/gpu/drm/xe/xe_exec_queue.h
> > index 289a3a51d2a2..ded77b0f3b90 100644
> > --- a/drivers/gpu/drm/xe/xe_exec_queue.h
> > +++ b/drivers/gpu/drm/xe/xe_exec_queue.h
> > @@ -75,6 +75,8 @@ 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);
> > +int xe_exec_queue_last_fence_test_dep(struct xe_exec_queue *q,
> > +				      struct xe_vm *vm);
> >   void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q);
> >   #endif