[PATCH v5 18/23] drm/xe/madvise: Skip vma invalidation if mem attr are unchanged

[Matthew Brost]

On Tue, Jul 22, 2025 at 07:05:21PM +0530, Himal Prasad Ghimiray wrote:
> If a VMA within the madvise input range already has the same memory
> attribute as the one requested by the user, skip PTE zapping for that
> VMA to avoid unnecessary invalidation.
> 
> v2 (Matthew Brost)
> - fix skip_invalidation for new attributes
> - s/u32/bool
> - Remove unnecessary assignment  for kzalloc'ed
> 
> Suggested-by: Matthew Brost <matthew.brost at intel.com>

Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm_madvise.c | 52 +++++++++++++++++++++---------
>  drivers/gpu/drm/xe/xe_vm_types.h   |  6 ++++
>  2 files changed, 42 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm_madvise.c b/drivers/gpu/drm/xe/xe_vm_madvise.c
> index 727833780b4b..fbb6aa8a7a5e 100644
> --- a/drivers/gpu/drm/xe/xe_vm_madvise.c
> +++ b/drivers/gpu/drm/xe/xe_vm_madvise.c
> @@ -84,13 +84,19 @@ static void madvise_preferred_mem_loc(struct xe_device *xe, struct xe_vm *vm,
>  	xe_assert(vm->xe, op->type == DRM_XE_MEM_RANGE_ATTR_PREFERRED_LOC);
>  
>  	for (i = 0; i < num_vmas; i++) {
> -		vmas[i]->attr.preferred_loc.devmem_fd = op->preferred_mem_loc.devmem_fd;
> -
> -		/* Till multi-device support is not added migration_policy
> -		 * is of no use and can be ignored.
> -		 */
> -		vmas[i]->attr.preferred_loc.migration_policy =
> +		if (vmas[i]->attr.preferred_loc.devmem_fd == op->preferred_mem_loc.devmem_fd &&
> +		    vmas[i]->attr.preferred_loc.migration_policy ==
> +		    op->preferred_mem_loc.migration_policy) {
> +			vmas[i]->skip_invalidation = true;
> +		} else {
> +			vmas[i]->skip_invalidation = false;
> +			vmas[i]->attr.preferred_loc.devmem_fd = op->preferred_mem_loc.devmem_fd;
> +			/* Till multi-device support is not added migration_policy
> +			 * is of no use and can be ignored.
> +			 */
> +			vmas[i]->attr.preferred_loc.migration_policy =
>  						op->preferred_mem_loc.migration_policy;
> +		}
>  	}
>  }
>  
> @@ -105,7 +111,12 @@ static void madvise_atomic(struct xe_device *xe, struct xe_vm *vm,
>  	xe_assert(vm->xe, op->atomic.val <= DRM_XE_ATOMIC_CPU);
>  
>  	for (i = 0; i < num_vmas; i++) {
> -		vmas[i]->attr.atomic_access = op->atomic.val;
> +		if (vmas[i]->attr.atomic_access == op->atomic.val) {
> +			vmas[i]->skip_invalidation = true;
> +		} else {
> +			vmas[i]->skip_invalidation = false;
> +			vmas[i]->attr.atomic_access = op->atomic.val;
> +		}
>  
>  		bo = xe_vma_bo(vmas[i]);
>  		if (!bo)
> @@ -130,9 +141,14 @@ static void madvise_pat_index(struct xe_device *xe, struct xe_vm *vm,
>  
>  	xe_assert(vm->xe, op->type == DRM_XE_MEM_RANGE_ATTR_PAT);
>  
> -	for (i = 0; i < num_vmas; i++)
> -		vmas[i]->attr.pat_index = op->pat_index.val;
> -
> +	for (i = 0; i < num_vmas; i++) {
> +		if (vmas[i]->attr.pat_index == op->pat_index.val) {
> +			vmas[i]->skip_invalidation = true;
> +		} else {
> +			vmas[i]->skip_invalidation = false;
> +			vmas[i]->attr.pat_index = op->pat_index.val;
> +		}
> +	}
>  }
>  
>  typedef void (*madvise_func)(struct xe_device *xe, struct xe_vm *vm,
> @@ -158,17 +174,20 @@ static u8 xe_zap_ptes_in_madvise_range(struct xe_vm *vm, u64 start, u64 end)
>  				  false, MAX_SCHEDULE_TIMEOUT) <= 0)
>  		XE_WARN_ON(1);
>  
> -	tile_mask = xe_svm_ranges_zap_ptes_in_range(vm, start, end);
> -
>  	drm_gpuvm_for_each_va_range(gpuva, &vm->gpuvm, start, end) {
>  		struct xe_vma *vma = gpuva_to_vma(gpuva);
>  
> -		if (xe_vma_is_cpu_addr_mirror(vma))
> +		if (vma->skip_invalidation)
>  			continue;
>  
> -		for_each_tile(tile, vm->xe, id) {
> -			if (xe_pt_zap_ptes(tile, vma)) {
> -				tile_mask |= BIT(id);
> +		if (xe_vma_is_cpu_addr_mirror(vma)) {
> +			tile_mask |= xe_svm_ranges_zap_ptes_in_range(vm,
> +								      xe_vma_start(vma),
> +								      xe_vma_end(vma));
> +		} else {
> +			for_each_tile(tile, vm->xe, id) {
> +				if (xe_pt_zap_ptes(tile, vma)) {
> +					tile_mask |= BIT(id);
>  
>  				/*
>  				 * WRITE_ONCE pairs with READ_ONCE
> @@ -176,6 +195,7 @@ static u8 xe_zap_ptes_in_madvise_range(struct xe_vm *vm, u64 start, u64 end)
>  				 */
>  				WRITE_ONCE(vma->tile_invalidated,
>  					   vma->tile_invalidated | BIT(id));
> +				}
>  			}
>  		}
>  	}
> diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
> index cd94d8b5819d..81d92d886578 100644
> --- a/drivers/gpu/drm/xe/xe_vm_types.h
> +++ b/drivers/gpu/drm/xe/xe_vm_types.h
> @@ -157,6 +157,12 @@ struct xe_vma {
>  	/** @tile_staged: bind is staged for this VMA */
>  	u8 tile_staged;
>  
> +	/**
> +	 * @skip_invalidation: Used in madvise to avoid invalidation
> +	 * if mem attributes doesn't change
> +	 */
> +	bool skip_invalidation;
> +
>  	/**
>  	 * @ufence: The user fence that was provided with MAP.
>  	 * Needs to be signalled before UNMAP can be processed.
> -- 
> 2.34.1
>