Re: [PATCH v4 4/5] drm/xe: Timeslice GPU on atomic SVM fault

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 22-04-2025 22:34, Matthew Brost wrote:
> Ensure GPU can make forward progress on an atomic SVM GPU fault by
> giving the GPU a timeslice of 5ms
> 
> v2:
>   - Reduce timeslice to 5ms
>   - Double timeslice on retry
>   - Split out GPU SVM changes into independent patch
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_svm.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index f749ae367a8f..d5376a76cdd1 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -783,6 +783,8 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
>   			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR) ? SZ_64K : 0,
>   		.devmem_only = atomic && IS_DGFX(vm->xe) &&
>   			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
> +		.timeslice_ms = atomic && IS_DGFX(vm->xe) &&
> +			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR) ? 5 : 0,
>   	};
>   	struct xe_svm_range *range;
>   	struct drm_gpusvm_range *r;
> @@ -819,6 +821,7 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
>   	if (--migrate_try_count >= 0 &&
>   	    xe_svm_range_needs_migrate_to_vram(range, vma)) {
>   		err = xe_svm_alloc_vram(vm, tile, range, &ctx);
> +		ctx.timeslice_ms <<= 1;	/* Double timeslice if we have to retry */

LGTM
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

>   		if (err) {
>   			if (migrate_try_count || !ctx.devmem_only) {
>   				drm_dbg(&vm->xe->drm,