Commit 1b36ea2f authored by Matthew Brost's avatar Matthew Brost Committed by Lucas De Marchi
Browse files

drm/xe: Timeslice GPU on atomic SVM fault 



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
v5:
 - Double timeslice in a few more places

Fixes: 2f118c94 ("drm/xe: Add SVM VRAM migration")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarHimal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://lore.kernel.org/r/20250512135500.1405019-5-matthew.brost@intel.com


(cherry picked from commit a5d8d3be)
Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent df8c3781

drivers/gpu/drm/xe/xe_svm.c

+5 −0
Original line number Diff line number Diff line
@@ -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 */

		if (err) {

			if (migrate_try_count || !ctx.devmem_only) {

				drm_dbg(&vm->xe->drm,
@@ -838,6 +841,7 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 
	err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, r, &ctx);

	/* Corner where CPU mappings have changed */

	if (err == -EOPNOTSUPP || err == -EFAULT || err == -EPERM) {

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

		if (migrate_try_count > 0 || !ctx.devmem_only) {

			if (err == -EOPNOTSUPP) {

				range_debug(range, "PAGE FAULT - EVICT PAGES");
@@ -877,6 +881,7 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 
			drm_exec_fini(&exec);

			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;

			}