[Intel-xe] [PATCH v2 2/3] drm/xe/bo: consider dma-resv fences for clear job

[Thomas Hellström]

On 10/27/23 12:48, Matthew Auld wrote:
> There could be active fences already in the dma-resv for the object
> prior to clearing. Make sure to input them as dependencies for the clear
> job.
>
> v2 (Matt B):
>    - We can use USAGE_KERNEL here, since it's only the move fences we
>      care about here. Also add a comment.

LGTM.

Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>


> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Cc: Matthew Brost <matthew.brost at intel.com>
> ---
>   drivers/gpu/drm/xe/xe_migrate.c | 16 ++++++++++++++--
>   1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
> index 009d728af762..e6a31f90ebdb 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.c
> +++ b/drivers/gpu/drm/xe/xe_migrate.c
> @@ -980,8 +980,6 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>   
>   		size -= clear_L0;
>   
> -		/* TODO: Add dependencies here */
> -
>   		/* Preemption is enabled again by the ring ops. */
>   		if (!clear_vram) {
>   			emit_pte(m, bb, clear_L0_pt, clear_vram, &src_it, clear_L0,
> @@ -1010,6 +1008,18 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>   		}
>   
>   		xe_sched_job_add_migrate_flush(job, flush_flags);
> +		if (!fence) {
> +			/*
> +			 * There can't be anything userspace related at this
> +			 * point, so we just need to respect any potential move
> +			 * fences, which are always tracked as
> +			 * DMA_RESV_USAGE_KERNEL.
> +			 */
> +			err = job_add_deps(job, bo->ttm.base.resv,
> +					   DMA_RESV_USAGE_KERNEL);
> +			if (err)
> +				goto err_job;
> +		}
>
>   		xe_sched_job_arm(job);
>   		dma_fence_put(fence);
> @@ -1024,6 +1034,8 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>   		xe_bb_free(bb, fence);
>   		continue;
>   
> +err_job:
> +		xe_sched_job_put(job);
>   err:
>   		mutex_unlock(&m->job_mutex);
>   		xe_bb_free(bb, NULL);