Re: [CI 3/3] drm/xe: Move vma rebinding to the drm_exec locking loop

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

On Thu, Mar 07, 2024 at 05:41:19PM +0100, Thomas Hellström wrote:
> Rebinding might allocate page-table bos, causing evictions.
> To support blocking locking during these evictions,
> perform the rebinding in the drm_exec locking loop.
> 
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>  drivers/gpu/drm/xe/xe_exec.c |  4 ++++
>  drivers/gpu/drm/xe/xe_vm.c   | 12 +++++++-----
>  2 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_exec.c b/drivers/gpu/drm/xe/xe_exec.c
> index 5124663a9694..b683ce415ef1 100644
> --- a/drivers/gpu/drm/xe/xe_exec.c
> +++ b/drivers/gpu/drm/xe/xe_exec.c
> @@ -106,6 +106,10 @@ static int xe_exec_fn(struct drm_gpuvm_exec *vm_exec)
>  	if (ret)
>  		return ret;
>  
> +	ret = xe_vm_rebind(vm, false);
> +	if (ret)
> +		return ret;
> +

This needs to be moved below the slot resveration to avoid [1].

Matt

[1] https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-130871v1/bat-atsm-2/igt@xe_exec_threads@threads-mixed-shared-vm-userptr-invalidate-race.html

>  	/*
>  	 * 1 fence slot for the final submit, and 1 more for every per-tile for
>  	 * GPU bind and 1 extra for CPU bind. Note that there are potentially
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index d9487b39778e..dbfdfd3ee39c 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -516,7 +516,13 @@ static int xe_preempt_work_begin(struct drm_exec *exec, struct xe_vm *vm,
>  	if (err)
>  		return err;
>  
> -	return drm_gpuvm_validate(&vm->gpuvm, exec);
> +	err = drm_gpuvm_validate(&vm->gpuvm, exec);
> +	if (err)
> +		return err;
> +
> +	err = xe_vm_rebind(vm, true);
> +
> +	return err;
>  }
>  
>  static void preempt_rebind_work_func(struct work_struct *w)
> @@ -568,10 +574,6 @@ static void preempt_rebind_work_func(struct work_struct *w)
>  	if (err)
>  		goto out_unlock;
>  
> -	err = xe_vm_rebind(vm, true);
> -	if (err)
> -		goto out_unlock;
> -
>  	if (vm->rebind_fence) {
>  		dma_fence_wait(vm->rebind_fence, false);
>  		dma_fence_put(vm->rebind_fence);
> -- 
> 2.44.0
>