Commit 265fa069 authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/xe: Don't use drm exec locking in SVM pagefaults 



Only the VM dma-resv lock is needed in SVM pagefaults so
xe_vm_lock/unlock can be used instead of drm exec. Micro optimization
but should save some CPU cycles in a critical path.

Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: default avatarStuart Summers <stuart.summers@intel.com>
Link: https://lore.kernel.org/r/20250603174012.2195759-1-matthew.brost@intel.com
parent 0ed4b3c2

drivers/gpu/drm/xe/xe_svm.c

+13 −23
Original line number Diff line number Diff line
@@ -858,7 +858,6 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 
			vm->xe->atomic_svm_timeslice_ms : 0,

	};

	struct xe_svm_range *range;

	struct drm_exec exec;

	struct dma_fence *fence;

	struct xe_tile *tile = gt_to_tile(gt);

	int migrate_try_count = ctx.devmem_only ? 3 : 1;
@@ -933,30 +932,21 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 
	range_debug(range, "PAGE FAULT - BIND");



retry_bind:

	drm_exec_init(&exec, 0, 0);

	drm_exec_until_all_locked(&exec) {

		err = drm_exec_lock_obj(&exec, vm->gpuvm.r_obj);

		drm_exec_retry_on_contention(&exec);

		if (err) {

			drm_exec_fini(&exec);

			goto err_out;

		}



	xe_vm_lock(vm, false);

	fence = xe_vm_range_rebind(vm, vma, range, BIT(tile->id));

	if (IS_ERR(fence)) {

			drm_exec_fini(&exec);

		xe_vm_unlock(vm);

		err = PTR_ERR(fence);

		if (err == -EAGAIN) {

			ctx.timeslice_ms <<= 1;	/* Double timeslice if we have to retry */

			range_debug(range, "PAGE FAULT - RETRY BIND");

			goto retry;

		}

			if (xe_vm_validate_should_retry(&exec, err, &end))

		if (xe_vm_validate_should_retry(NULL, err, &end))

			goto retry_bind;

		goto err_out;

	}

	}

	drm_exec_fini(&exec);

	xe_vm_unlock(vm);



	dma_fence_wait(fence, false);

	dma_fence_put(fence);