drm/xe/vm: Defer vm rebind until next exec if nothing to execute

If all compute engines of a vm in compute mode are idle,
defer a rebind to the next exec to avoid the VM unnecessarily trying
to make memory resident and compete with other VMs for available
memory space.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 6cc3204adaa8..207d20da5c68 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -226,6 +226,19 @@ static int wait_for_existing_preempt_fences(struct xe_vm *vm)
 	return 0;
 }
 
+static bool xe_vm_is_idle(struct xe_vm *vm)
+{
+	struct xe_engine *e;
+
+	xe_vm_assert_held(vm);
+	list_for_each_entry(e, &vm->preempt.engines, compute.link) {
+		if (!xe_engine_is_idle(e))
+			return false;
+	}
+
+	return true;
+}
+
 static void arm_preempt_fences(struct xe_vm *vm, struct list_head *list)
 {
 	struct list_head *link;
@@ -548,6 +561,11 @@ retry:
 	if (err)
 		goto out_unlock_outer;
 
+	if (xe_vm_is_idle(vm)) {
+		vm->preempt.rebind_deactivated = true;
+		goto out_unlock;
+	}
+
 	/* Fresh preempt fences already installed. Everyting is running. */
 	if (!preempt_fences_waiting(vm))
 		goto out_unlock;